Micro Drainage Uk Manual

7/17/2019 Micro Drainage Uk Manual

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INDUSTRY STANDARD DRAINAGE DESIGN SOFTWARE

APTCASDeF CC

M D

DNFloodFlow PQuOSTSIM SCSYS1

USER MANUAL



Revision 0 January 2014 Micro Drainage® 2014

Micro Drainage®



Examples - introduction Page 0.1

Working with Micro Drainage®

An example ledintroduction to the

Micro Drainage suite.



Page 0.2 Examples - introduction

Contents

Introduction, Installation, Help

Example 1System 1 - The Modified Rational Method

Example 2System 1 - Open Channel Design

Example 3

System 1 - Schedules, Longsections, Plan & 3D Graphics

Example 4System 1 - Foul Sewer Design with Schedules

Example 5Source Control - Storage Lake

Example 6Source Control - Tank Sewer

Example 7Simulation - Simulation of a drainage system with tank sewers

Example 8Simulation - Advanced Productivity Tools & CASDeF

Example 9Channel - The Backwater Step Method

Example 10Source Control - Infiltration Systems

Example 11QuOST - Quantities & Costings




Example 12DrawNet (CAD) - Working within AutoCAD

®

Example 13DrawNet - Graphical Model Build

Example 14FloodFlow - Overland Flow Path Analysis

Example 15Pluvius – Use of Extended Time Series Rainfall

AppendicesAppendix i

Appendix ii

Appendix iii

Appendix iv

Appendix v

Hydraulic Conduits

IDF, CRP and Hyetograph

Rural Discharge

Unit Hydrograph

Allowable discharge for Example 8




IntroductionThese examples are designed to give you hands-on experience of working

with Micro Drainage. They have been created to demonstrate the key features

and benefits of the program by addressing most of the common problemsencountered in the analysis and design of drainage networks.

You should use them in conjunction with the program, referring to the results

on-screen where necessary. Images from the program have been used to

illustrate the main points of the procedure.

Installing Micro Drainage

With this pack you will have the Micro Drainage installation DVD and adongle.

To install Micro Drainage insert the DVD into the DVD-ROM drive. Do not

connect dongle until after the software is installed.

Note: Micro Drainage will not run without the dongle - always make sure it

is properly in place before trying to run Micro Drainage.

If you have Autoplay running, the installation procedure will launch

automatically and you will see the Micro Drainage Setup window.




If autoplay is switched off or is not available then proceed as follows:

• From the Start menu select the Run… option.

• At the Run window type the letter of your DVD-ROM drive followed

by :\setup (e.g. d:\setup).

• Click OK .

At the Setup Window select Install Micro Drainage. The program will

display any relevant last minute instructions. When you are happy you are

ready to proceed click the Install Micro Drainage button.

Follow the on-screen prompts. When the Select Installation Folder window

appears, ensure the destination directory is correct.

Click Next to proceed through the Installation wizard.




Upgrade copiesIf you are upgrading an existing copy of Micro Drainage, follow the

installation procedure as if you were installing a new copy.

Installing a Network copy

Windows ServerA License Manager must be installed and running on the server before the

software can be installed to the client machines. This can be achieved by

selecting the License Manager option from the Autoplay menu, or by running

the LMSetup.exe program located in the \Hasp directory on the DVD.

The License Manager will require the red dongle to be connected to a free

USB port on the server.

If you wish to run Micro Drainage on the server then follow the same

procedure as above.

Windows Workstations

Follow the same procedure as for a standalone copy.

General NotesMicro Drainage requires a device driver (haspdinst) to allow communication

with the dongle. This is installed automatically by the Setup program. Please

ensure this can be accomplished before you begin. The device driver is

loaded dynamically (no reboot is required), however this requires you to be

logged in as the Windows Administrator.




HelpThe DVD contains a host of other information relevant to installing and

getting started with Micro Drainage. See the What’s New / Help option for

the latest installation details or to see the major new features in MicroDrainage 2014.

The topic entitled Read Me contains late breaking information. It is

recommended you read this before using the software.

The Help system can be accessed from any of the modules by either clicking

the Help button (found on most of the dialogue boxes), or by pressing the F1key.

MDHelp provides you with valuable technical data and the detail behind the

operation of each module. It follows standard HTML (web page) protocols,

with blue text to help you switch between topics.

The Contents pane gives you a general overview of the topics covered by

Help. However, for a detailed listing of the topics, and to find help quickly ona specific subject, we recommend that you use the Index or Search.




Once you have found the section you want, use the browse buttons at the top

of the window to move forwards and backwards through the text.

Browse buttons

How Do ITutorials are also available for the most commonly asked questions. The

tutorials are contained in the last book in the Contents or can be accessed

directly from the Help menu in any of the modules.

The problems are listed in two sections, By Module and By Theme. To find

the help you require expand the trees.

XP Solutions reserves the right to change any part of the Micro Drainage suite of programs without prior notice. © XP Solutions 2014 XP Solutions recognises all trademarks.



Example 1 Page 1.1


Example 1 – System 1The Modified Rational Method



Page 1.2 Example 1

IntroductionThis example takes you step-by-step through a typical network design, using

the Modified Rational Method as applied within the System 1 module of

Micro Drainage. It has been created to give you hands-on experience ofworking with Micro Drainage.

Loading NetworkSelect the Start button and open the Micro Drainage 2014 menu from within

the Programs menu:

Click the module you wish to work with. For this example, select Network .

This will open all the network build modules held on your licence, and will

include System 1.

You will now see the Open dialogue box. Click Cancel and we will orientate

ourselves with the Micro Drainage package.

Select Module Selector from the Window menu and the screen overleaf

appears.

The Module Selector is the main selection menu of all the Micro Drainage

programs. It allows the user to change modules or add modules to the current



Example 1 Page 1.3

program. The modules in colour are those currently running. You can add or

remove a module by clicking on it.

System1, Simulation, DrawNet and QuOST are grouped under Network, but

can be run separately. APT, CASDeF and FloodFlow add additionalfunctionality to these modules. Source Control, Channel and Pluvius are

separate executables and can be launched from the Module Selector.

If you select a module that is not available on your licence you will be

offered the option to start the 30 Day Time Trial. This allows you to try-out

all modules that have not been purchased for 30 days.

The current active modules are listed in the bottom left-hand corner of the

screen. In the Module Selector select the System 1 module so its’ icon is

coloured ; turn off all other modules by selecting them so they grey out.

Menus within the program will update to display all available options for

active modules.



Page 1.4 Example 1

The Edit menu presents you with options for the preparation and selection of

pipe, manhole, conduit and rainfall libraries which are also available where

required within each module. For these functions, see Appendix i and

Appendix ii, though you do not need them for this example.

The Options menu gives you the choice of industry standard formulae for the

hydraulic gradient and flow calculations. You can choose the combination

which best suits your requirements, but note that once you have started a

project you cannot go back and change your selection for that project.

Close the form by selecting the cross. You are now ready to start the first

example.



Example 1 Page 1.5

Start a New Job

Reopen the System 1 Open dialogue box by selecting Open from the File

menu. Choose the New Storm option by highlighting it and then clicking OK .

Design CriteriaYou will now see the Design Criteria screen:



Page 1.6 Example 1

Rainfall Details Begin by choosing the Rainfall Method. For this example we will accept FSR

Rainfall and England & Wales for the Region. In a real project you would

select the method and Region by clicking on the arrow to the right of the box.

See Appendix iii for more details on how to use an IDF Library.

Note: FEH Rainfall should not be used below 30 minutes duration. This

means that until further research is carried out by CEH Wallingford to

confirm its use for short durations, it cannot be used for a time of

concentration below 30 minutes.

In the case of hydrograph methods (Simulation and Source Control) if the

15 minute storm is critical then it should be checked using FSR unless

there is further advice from CEH Wallingford.

Proceed to enter the remaining Design Criteria as shown on page 1.5.

Note: All these values can be entered by clicking on the relevant box or

by using the keyboard arrows and then typing.

Pipe and Manhole SizesMicro Drainage allows you to specify your own pipe and manhole libraries

instead of the Standard libraries shown by default. Simply click on the button

next to the Pipes box and the Pipe Sizes form appears.



Example 1 Page 1.7

You may create your own library which can be saved for future use. Or you

can load any pipe library saved as a file with the extension .pipx. The same

approach is taken to change the manhole sizes.

Manhole size library files have the extension .mhsx. Size libraries can also becreated and edited from the Edit menu in the Module selector available from

the Window menu. Further information is given in the Help.

When you have finished entering the data, click OK to proceed.

Creating the network - Network DetailsSystem 1 will now present you with the Network Details spreadsheet.

We will use this spreadsheet to design the following drainage network:

1.000

1.001

1.002

1.004

2.001

2.000

1.003

3.000

The known data for the network are as follows:



Page 1.8 Example 1

Pipe Pipe Fall Slope Area Time Base Pipe US/IL US/CL Pipe

no length [m] [1:x] Entry Flow Rough [m] [m] DIA

1.000 100 1.000 0.25 5 10 0.6 100 R R

1.001 50 R 100 0.5 R R

2.000 20 0.25 0.01 R R R 100 R R

3.000 35.5 R 125 0.02 R R R 100 R R

2.001 21.6 R R R R R

1.002 25 R R 1.52 R 356

1.003 78.9 R 490 5.7 R 2

1.004 100 R 500 R R 1500

Note: Here, R denotes Return. Where no entry is shown, System 1 will

automatically skip the column. This procedure applies within all

subsequent examples. Note also that where a pipeline is entered in

sequence, you can hit Return instead of entering the next pipe number.

Thus for pipe 1.001 you could use the Return key; however, pipe 2.000

breaks the sequence and must be entered manually. We will now proceed to enter each line in turn.

Completing the spreadsheet Note that the first box of the spreadsheet is automatically highlighted. Enter

the data for pipe 1.000 by typing the numbers and pressing Return.



1.000 100 1.000 0.25 5 10 0.6 100 R R

Note that Slope calculates automatically and that Pipe Diameter calculates

when you hit Return for the last time. System 1 will always automatically

select the smallest available section from the pipe library you have chosen -

in this case, the Standard pipe library. In a live project, do not enter a value

for Pipe Diameter unless you are sure it is appropriate to do so - for instance

if you are working with an existing network.



Example 1 Page 1.9

Upstream Invert Levels, Area and Time of Entry are shown in red, because

they are values which you have specified and are not calculated by System 1.

Immediate feedback Note how the results of your entries are automatically calculated in the lower

row. This means that you can see immediately whether or not the values you

have used are achieving the desired effect.

Correcting errorsIf you are not satisfied with the data in the upper half of your spreadsheet,

you can correct any errors simply by highlighting the box concerned. This

can be done either with the mouse (by pointing and clicking) or using the

keyboard arrows. When the box is highlighted simply key in the correct

values.

Note: If you do not specify a pipe number or length, System 1

automatically warns you to do so before allowing you to move on.

Pipe 1.001First, experiment with the error facility by entering 1.002 for Pipe Number .

System 1 warns you that it is an Invalid Pipe Number. Enter the correct

value, followed by the remainder of this sequence:



1.001 50 R 100 0.5 R R

Notice how Fall automatically calculates when you key in the value for

Slope.

After you have entered Area, System 1 automatically takes you to US/CL

(upstream cover levels), since the program automatically calculates the

values in between. We will be entering cover levels later, so here simply hit

Return to move to Pipe Diameter . Hitting Return here (or entering 0)

automatically calculates the value and moves you to the next row of the

spreadsheet.

You can alter the automatic calculations if you need to, using the keyboard or



Page 1.10 Example 1

mouse as described previously. However, Time of Entry cannot, of course, be

changed as this is only required at the head of a branch line.

Equally, you should not specify an upstream invert level (US/IL) unless you

wish to specify a backdrop. System 1 automatically places the pipes soffit-to-soffit or invert-to-invert, in accordance with the options chosen in the Design

Criteria. Accordingly, the automatically calculated invert level is shown in

blue, whereas an invert level which you specified would show as red.

Pipes 2.000 and 3.000 Now enter the following two rows:

Pipe Pipe Fall Slope Area Time Base Pipe US/IL US/CL Pipeno length [m] [1:x] Entry Flow Rough [m] [m] DIA

2.000 20 0.25 0.01 R R R 100 R R

3.000 35.5 R 125 0.02 R R R 100 R R

As both these pipes are at the head of a branch line, the Time of Entry is

automatically entered, using your original specified time (5) as a default.

Similarly, Pipe Roughness defaults to 0.6; if you alter this value, the new

value will then be used as the new default by the program.

In this instance, pipes 2.000 and 3.000 have a velocity which is below the

recognised minimum of 1m/s as specified by Sewers for Adoption.

Accordingly, they are shown in green.

Note: Some specifications are less stringent and require 0.7m/s (EN 752).

0.75m/s has been the traditional minimum (formerly 2½ ft/s CP2005 1969)

used for several decades and can be acceptable to approving authorities

where pumping can be avoided by its adoption.

Pipe 2.001 Now enter this row:




Example 1 Page 1.11

2.001 21.6 R R R R R

Note that Fall, Slope and Diameter are not specified here. This is the only

time that the program uses the minimum velocity specified in the Design

Criteria. This is what is meant by Auto-Design in the Design Criteria screen.

A diameter and slope (or fall) will be chosen by System 1, which will yield a

velocity within the specified range. However, note that if a slope or fall is

chosen, then the program chooses the smallest diameter, regardless of

velocity. Conversely, if a diameter is chosen and not a slope/fall, then the

program calculates the minimum slope required to take the flow - again,

regardless of velocity.

In addition, note that the slope of 2.000 is automatically altered to bring its

downstream end level with 3.000, removing a small backdrop. The note at

the bottom of the screen tells you that this has been done.

Pipe 1.002Enter the following row:


1.002 25 R R 1.52 R 356

Here, you specify the diameter and the 356 appears in red. The slope is given

to closely match the flow. As you can see, you can specify non-standard

diameters as well as standard diameters.




1.003 78.9 R 490 5.7 R 2

This time you are specifying both the Diameter and the Slope. It is no

mistake that the diameter is 2. When you specify a diameter, which is less

than 66 you are in fact specifying a hydraulic section, which is held in aninternal library of the most commonly used non-circular sections.



Page 1.12 Example 1

The properties of these sections, which include box culverts, open channels,

double and triple pipelines and egg shaped sewers, can be viewed by clicking

the Conduits button when you are in the Diameter column of the spreadsheet.

In a real project you can also create or load a conduit library of your own.Appendix ii has full details of this facility.




1.004 100 R 500 R R 1500

Here we specify both Slope and Diameter , as you would if the pipe already

existed. The 1500mm pipe has spare capacity and the program accepts it. If

the pipe was under capacity, System 1 would overrule you and increase the

diameter. A way to avoid this automatic upgrading when you are working

with an existing system that may be overloaded is explained in a later

example.

Checking your entryYour Network Details spreadsheet should now look like the following

example:



Example 1 Page 1.13

Saving your work and opening new projectsBefore we examine how to edit data in a completed project, we will save and

re-open this finished version. To do so, select Save from the File menu.

You will then be presented with the Save Network File window:

In the File name box enter the title Example1 and click Save, or press Return.

Note: System 1 is not case-sensitive when searching for file names, so the

use of capitals is not essential when opening or re-opening files.

To confirm that your file has been saved, exit from System 1 by selecting

Exit from the File menu.

Now follow the procedure for opening System 1 via the Start button we usedat the beginning of this example.

When the Open screen appears, the option to continue with Example1.mdx

will be displayed. Click on its icon to highlight it and select OK , and you are

returned to the Network Details screen.

You can open and save files quickly using the toolbar icons:

Saves your file

Opens a file

Editing



Page 1.14 Example 1

Editing an existing l ineGo to pipe 1.001, either by using the scroll bar and clicking on that line or by

using the keyboard arrows. Enter a value of 125 for Slope - don't forget to hitReturn. System 1 automatically re-calculates the values for pipe 1.001 and all

pipes downstream.

Note: If you now try to alter the value for Slope again, you will find that

the cursor automatically highlights Fall and not Slope. To re-calculate

Slope, enter a 0 for Fall and the original value of 100 for Slope. Once again

System 1 re-calculates and a value of 0.500 is restored for Fall.

Deleting a pipeHighlight pipe 1.001. To delete this pipe, click on the Delete Pipe icon in the

toolbar.

Deletes a pipe

The Delete Pipe dialogue box now appears.

The number of the pipe highlighted is automatically shown. However, you

can select another pipe number if you prefer. To delete the pipe, simply click

OK or press Return.

Note: When you delete pipe 1.001, System 1 automatically re-numbers the

remaining pipes, e.g. pipe 1.002 is now pipe 1.001, pipe 1.003 is now pipe

1.002 etc.



Example 1 Page 1.15

Inserting a pipeTo insert a pipe, highlight a pipe following the point at which you wish to

insert a new pipe. For this example, click on pipe 1.001. Then choose the

Insert Pipe icon.

Inserts a pipe

The Insert Pipe dialogue box now appears. We have two choices. Upstream

of… is to insert a pipe which flows into the selected pipe, as would be

required here. Downstream of… is to insert a pipe which receives flow from

the selected pipe.

You can accept the number of the specified pipe, or select a different pipe

from the network. However, for this example click Cancel, because we will

shortly restore pipe 1.001 using a different function.

If you had clicked OK , System 1 would have inserted a blank row above pipe

1.001 and would again automatically re-number the rest of the spreadsheet.

Re-inserting the deleted pipe – Revision ManagerSelecting Previous Revision from the File menu re-inserts the pipe youdeleted. This uses the Revision Manager function which stores a history of

data states and edit actions in a database which can be viewed by selecting

Revision Manager from the File menu.



Page 1.16 Example 1

The Revision Manager will be operating if Save Undo Information is

checked on under the Settings tab. The History tab shows all saved revisions

which can be restored by selecting a Revision and clicking Undo.

Longitudinal sectionThe Longsections function gives you a full graphic representation of the

network. To display a longitudinal section, click the Longsections icon.

Longsections

The screen presents you with a Longitudinal section at the point within the

network corresponding to the location of the cursor on the spreadsheet. The

default settings only show 1 pipe.

Previous pipes displayed

Above the Longsection itself is a command enabling you to alter the numberof pipes displayed on the screen at one time.

To increase the number of pipes, click the up arrow. To reduce the number of

pipes, click the down arrow. Alternatively type in the box the number of

pipes you wish to view and the Longsection will automatically update.

You can experiment with this facility by moving the box to the right-hand

side of the scroll bar. In our example, there are five different pipes in the



Example 1 Page 1.17

main line; System 1 allows you to view up to thirty pipes at a time.

Click the up or down arrow until the command reads 5 or simply type 5 in the

box. You will now see all pipes of the main line displayed in longsection.

Now click the down arrow, so that the command reads 4.

System 1 removes pipe 1.000 and zooms you in closer to the remaining pipes

displayed. Change the number of pipes displayed back to 5.

Note: If you had clicked the up arrow, the screen would have remained

unchanged, since there are only five pipes in this line.

There are several icons above the Longsection which we can use to adjust thedisplay. Click the icon below to view the cross-section of each pipe showing

the proportional depth and proportional velocity of the flow.

Show Cross-section

You can move along the network using the box in the scroll bar beneath the

display. Move the box to the right-hand end of the bar to see a full display.



Page 1.18 Example 1

Note: The blue circle for pipe 2.001 is shown above the pipeline profile, to

indicate that a backdrop has been incorporated at the junction of the two

lines. This is because the invert level for pipe 2.001 (99.716) lies outside

the minimum backdrop height of 0.200m specified in Design Criteria. Hadit fallen within the specified minimum, System 1 would have automatically

recalculated to eliminate the requirement for a backdrop.

Branches can be turned on by depressing the Include branch lines option:

Include branch lines

Branch lines are shown in Blue, to change colours on screen or for printingsee Example 3. To view a branch, move the box so that the junction of the

branch with the main line is the last section to be displayed on the screen. In

this example, move the box approximately to the centre of the scroll bar.

You will now see pipes 2.000 and 2.001, with a blue circle indicating the

branch with pipe 3.000 and a pink circle showing where pipe 2.001 joins the

main network.



Example 1 Page 1.19

Pause?You have now completed the first stage of Example 1. This is an appropriate

place to take a break if you need one.

Managing windows in System 1A key benefit of Micro Drainage is the facility to move between the elements

of each module quickly and easily. Using our example, we will now practice

sizing windows and arranging them on the System 1 desktop.

Sizing windowsUse the Windows re-sizing button to shrink the Longsections screen without

sending it to the Task Bar.

You should now see a scaled down version of Longsections with the Network

Details spreadsheet behind it:



Page 1.20 Example 1

Switching between windowsFor this example, you are going to delete a pipe to demonstrate how System 1

automatically re-calculates between functions - and how easy it is to switch

between the functions to see the results.

First, click on the Design Criteria icon:

Design Criteria

Design Criteria appears in front of the existing screens. Then choose Cascade

from the Window menu and all three Windows are arranged tidily on the

screen.

Select the Network Details window by clicking in its title bar. You can work

with the data within the spreadsheet even though the window does not fill the

screen. To make all the title bars visible again, choose Cascade from the

Window menu.

Before proceeding, make sure you have saved all your work so far. Then

delete pipe 1.003, following the procedure set out in Deleting a pipe on page

1.14. Then click on the Longsections title bar and expand the screen byclicking the middle re-sizing button.

Adjust the scroll bar until the complete network is shown (by sliding the box

to the right-hand side of the scroll) and ensure that the command box at the

top of the screen shows 5 Pipes.

You will see that in fact only four pipes are displayed, since the original pipe

1.003 has been removed. Pipe 1.004 is the new pipe 1.003, as specified onthe Network Details spreadsheet. Finally, choose Cascade again to make all

three functions of System 1 visible.

Note: A quick way to switch between windows using the keyboard is to

hold down Ctrl and use the Tab button to toggle between the windows.

Before moving on, reinstate pipe 1.003 by selecting Previous Revision from

the File menu.



Example 1 Page 1.21

Note: If you are familiar with the clicking and dragging capabilities of

Windows, you may find it easier simply to click in the title bars of the

functions and drag them around the desktop, instead of using the Cascade

facility.

Auto-refreshIf Longsections was visible when you altered the pipeline details, you may

have noticed that the graphic of the network was automatically changed at the

same time. System 1 automatically refreshes Longsections whenever a

change is made to the spreadsheet. This is a particularly useful function,

allowing you to see each pipe in Longsection as it is added to the network.

OptimiseWe will now demonstrate the Optimise function, beginning by entering the

cover levels for the network we have already designed.

Entry of cover levelsEnter the following data for each pipe in the US/CL[m] column. Simply type

in the numbers and press the down arrow.

Pipe number US/CL [m] 1.000 103

1.001 100.5

2.000 102

3.000 102.5

2.001 100.8

1.002 100.7

1.003 99.2

1.004 98

System 1 warns you (in the Warning bar at the foot of the screen) that the

data is inconsistent with the depth of 1.2m designated in the Design Criteria.

To see the effect this has, look at Longsections. It may help if you turn on the

Show pipe bounds which displays the Design Depth.

Show pipe bounds



Page 1.22 Example 1

The effect is particularly marked at the conjunction of pipes 2.001 and 1.002.

Note the hydraulic grade line (HGL) which is shown in blue.

Next, return to Network Details and go to the Pipe DIA [mm] column. Delete

each of the entries shown in red - i.e. all those figures, which you specified,

rather than allowing System 1 to calculate them automatically - by entering

zero.

Hit Return as you delete each figure and System 1 automatically calculates

the new pipe diameters. Then simply click Optimise.

Optimise

The Optimise dialogue box now appears:



Example 1 Page 1.23

You have, of course, already asked System 1 to re-calculate your pipe

diameters. Click Yes or press Y.

System 1 re-calculates to produce the optimum design depth at 1.2m

throughout the entire network. To see the effect, go to Longsection again.

Note that 1.004 does not have its ground profile because the downstream

cover level is not known at this stage. In addition, you will see that design

depth has been set at 1.2m wherever possible. System 1 uses design depth,

measured from the connection height to cover level. This can be further

observed in the Network Details by looking at the Warnings/Notes box at the

bottom of the screen.

Obstructions underground - how to avoid themIn the event that your optimised network encounters an obstruction

somewhere along its length, such as an electrical cable or gas pipeline,

System 1 allows you to input a different invert level and pipe diameter for the

affected point.

In this case, let us assume that pipe 1.001 cannot be placed at the level

automatically calculated by System 1. Replace the upstream invert level witha value of 98, to allow the pipe to be laid below the service crossing, and the

pipe diameter with a value of 450. When the pipe diameter is entered (and

Return) both the level and diameter should be in red as they are user

specified. Optimise will now leave this pipe in place (unless it is too high or

has insufficient capacity).

Go to Longsections and note that the network once again fails to follow the

ground profile at the optimum depth. If you display the pipes downstreamyou will see that these pipes have also had their depths increased.

Return to Network Details and click Optimise, again choosing Yes at the

dialogue box. A return to Longsections shows how System 1 optimises the

network throughout its entire length, including the pipes downstream of the

fixed pipe which are once more at their minimum design depth.

This demonstrates System 1's capacity to optimise an entire system around

any number of fixed pipes within the network.



Page 1.24 Example 1

Note: As well as fixing pipes in space it is also possible to specify a

different required design depth on a pipe by pipe basis. In this instance pipe

1.001 would require a deeper design depth to drop it below the obstruction.

An extra column can be switched on in the spreadsheet from Preferencesavailable from the Network Details toolbar to allow this.

Automatic OptimisationFinally, let us now use the automatic optimisation facility built-in to System

1 to enter two more pipes.

Click the Optimise On icon in the toolbar:

Optimise On

Now key in the following pipe details:



1.005 50 R R 0.25 96.000 R

1.006 50 R 250 0.25 95.500 R R

Choose Longsection again and note how System 1 has automatically

specified the new pipes to follow the ground profile.

Designing to a Required OutfallMany new designs require you to connect into a fixed level, whether it is an

existing sewer or watercourse. Hitting this required level has always been the bane of the design engineer and designing from the outfall upwards goes

against the forward flow design path of the Modified Rational Method. To

reverse design is an onerous task to carry out by hand.

System 1 allows you to specify the required outfall level in the Outfall

Details and Optimise will redesign the system to meet this level.

The design we have completed has an outfall level of 93.2m. However the

outfall level we require is 94m so we have missed it by 800mm.



Example 1 Page 1.25

Open the Outfall Details by selecting it from the Network menu.

Enter 94 in the Min IL (m) box and then click OK .

Before we do the Full Optimise to meet our required outfall we need to turn

the Automatic Optimise function off. Click the icon in the toolbar to turn it

off.

Optimise Off

Now click the Full Optimise button and say Yes to the first warning message.

A second warning message will appear asking if you would like to raise the

outfall invert as it is lower than 94m.

Click Yes to this message and Optimise will redesign the system.



Page 1.26 Example 1

The Network Details show that the Downstream Invert Level for 1.006 has

been raised to meet our required outfall invert of 94m.

Note: As the message suggests a minimum invert level can be specified at

any point in the system. An extra column can be switched on in the

spreadsheet from Preferences to allow this.

In reaching our minimum outfall System 1 has had to break the minimum

cover rule of 1.2m in some places. Look at the Longsections to see the effect

of this. You will need to increase the number of pipes displayed to 7 to see

the entire network.



Example 1 Page 1.27

Network SchematicThis facility allows you to view a graphic model of the network. Click on the

Schematic icon:

Schematic

The schematic is presented showing whichever pipe is highlighted on the

pipeline details at the centre of the system. The pipe is shown in red. The

number of pipes to display will need to be increased to 6.

The rest of the pipes in any given line are shown in yellow, while branches

are shown in blue. Click on any pipe with the right mouse button and select

Properties and the properties of the pipe are shown in a popup window. For

more information on Properties see Example 13.

You can also move through the system by clicking on branches. Try clicking

on branch 2; pipes 2.000 and 2.001 are shown, with an arrow to depict the

conjunction with the main line:



Page 1.28 Example 1

Printing within System 1System 1 gives you the option to print a variety of hard copies, based on the

values calculated. All the print commands are located under the File menu.

A quicker way to open the dialogue box is to click the Print icon in the

toolbar:

Print

When you select Print, System 1 shows you the Print dialogue box:

These options are self-explanatory; you choose the options you would like to

print simply by clicking in the appropriate box. Click the Update Preview

button to see a print preview. When you are satisfied with the selected

options click the printer icon at the top of the dialogue to send the job to the

printer.

Page Setup… allows you to edit the margins. The printer can be chosen when

you click the print icon in the Print window.



XP Solutions Page 29

Jacobs Well Example 1

West Street System 1

Newbury RG14 1BD The Modified Rational Method

Date 04/12/2013 Designed by XP Solutions

File Example1.mdx Checked by

XP Solutions Network 2013.1.5

STORM SEWER DESIGN by the Modified Rational Method

Design Criteria for Storm

©1982-2013 XP Solutions

Pipe Sizes STANDARD Manhole Sizes STANDARD

FSR Rainfall Model - England and Wales

Return Period (years) 1 Add Flow / Climate Change (%) 20

M5-60 (mm) 20.000 Minimum Backdrop Height (m) 0.200

Ratio R 0.400 Maximum Backdrop Height (m) 1.500

Maximum Rainfall (mm/hr) 50 Min Design Depth for Optimisation (m) 1.200

Maximum Time of Concentration (mins) 30 Min Vel for Auto Design only (m/s) 1.00

Foul Sewage (l/s/ha) 1.000 Min Slope for Optimisation (1:X) 500

Volumetric Runoff Coeff. 0.750

Designed with Level Soffits

Time Area Diagram for Storm

Time

(mins)

Area

(ha)

Time

(mins)

Area

(ha)

Time

(mins)

Area

(ha)

0-4 4.200 4-8 4.263 8-12 0.037

Total Area Contributing (ha) = 8.500

Total Pipe Volume (m³) = 183.571

Network Design Table for Storm

PN Length

(m)

Fall

(m)

Slope

(1:X)

I.Area

(ha)

T.E.

(mins)

Base

Flow (l/s)

k

(mm)

HYD

SECT

DIA

(mm)

1.000 100.000 2.500 40.0 0.250 5.00 10.0 0.600 o 225

1.001 50.000 0.125 400.0 0.500 0.00 0.0 0.600 o 450

2.000 20.000 1.200 16.7 0.010 5.00 0.0 0.600 o 100

3.000 35.500 1.700 20.9 0.020 5.00 0.0 0.600 o 100

2.001 21.600 0.369 58.6 0.000 0.00 0.0 0.600 o 100

1.002 25.000 0.325 76.9 1.520 0.00 0.0 0.600 o 5251.003 78.900 1.200 65.8 5.700 0.00 0.0 0.600 o 750

Network Results Table

PN Rain

(mm/hr)

T.C.

(mins)

US/IL

(m)

Σ I.Area

(ha)

Σ Base

Flow (l/s)

Foul

(l/s)

Add Flow

(l/s)

Vel

(m/s)

Cap

(l/s)

Flow

(l/s)

1.000 50.00 5.80 101.575 0.250 10.0 0.3 8.8 2.07 82.5 52.9

1.001 48.01 6.63 98.000 0.750 10.0 0.8 21.7 1.01 160.7 129.9

2.000 50.00 5.18 100.700 0.010 0.0 0.0 0.3 1.90 14.9 1.6

3.000 50.00 5.35 101.200 0.020 0.0 0.0 0.5 1.70 13.3 3.3

2.001 50.00 5.71 99.500 0.030 0.0 0.0 0.8 1.01 7.9 4.9

1.002 47.44 6.79 97.800 2.300 10.0 2.3 61.6 2.56 553.3 369.4

1.003 46.17 7.17 97.250 8.000 10.0 8.0 203.7 3.45 1526.2 1222.0






Newbury RG14 1BD The Modified Rational Method






PN Length

(m)

Fall

(m)

Slope

(1:X)

I.Area

(ha)

T.E.

(mins)

Base

Flow (l/s)

k

(mm)

HYD

SECT

DIA

(mm)

1.004 100.000 1.550 64.5 0.000 0.00 0.0 0.600 o 750

1.005 50.000 0.100 500.0 0.250 0.00 0.0 0.600 o 1050

1.006 50.000 0.100 500.0 0.250 0.00 0.0 0.600 o 1050


PN Rain

(mm/hr)

T.C.

(mins)

US/IL

(m)

Σ I.Area

(ha)

Σ Base

Flow (l/s)

Foul

(l/s)

Add Flow

(l/s)

Vel

(m/s)

Cap

(l/s)

Flow

(l/s)

1.004 44.68 7.65 96.050 8.000 10.0 8.0 203.7 3.49 1540.7 1222.0

1.005 43.11 8.19 94.200 8.250 10.0 8.3 203.7 1.53 1328.5 1222.01.006 41.67 8.74 94.100 8.500 10.0 8.5 203.7 1.53 1328.5 1222.0

Free Flowing Outfall Details for Storm

Outfall

Pipe Number

Outfall

Name

C. Level

(m)

I. Level

(m)

Min

I. Level

(m)

D,L

(mm)

W

(mm)

1.006 0.000 94.000 94.000 0 0



Example 2 Page 2.1


Example 2 - System 1Open Channel Design



Page 2.2 Example 2

IntroductionPipe networks and open channels share many characteristics and it is

therefore appropriate to use System 1 for the design of an open channel

system.

In this example we will examine how a specific conduit library can be

created and analysed, using Micro Drainage’s integral conduit design facility.

We will also see how a network combining open channels and pipes can be

created.

The intention here is to keep all water levels below 600mm. However, in

order to allow the Simulation module to show overloading when it occurs, we

shall define the section to a depth of 1 metre.

Setting up the networkWe need only a few sections to demonstrate the principles involved. The

following network will be sufficient:



Example 2 Page 2.3

Begin by opening System 1 and select New Storm. Enter the Design Criteria

as follows:

Note that we have given the system 15% spare capacity by allowing for 15%

additional flow.

PreferenceClick OK to call up the Network Details spreadsheet. However, before

proceeding to enter any data, we need to add some additional columns to thespreadsheet.

This is done by selecting Preferences from the tool bar.

Preferences

The Preferences dialogue box presents you with a variety of options, which

help you tailor the Network Details spreadsheet to suit your requirements.



Page 2.4 Example 2

You can, for example, switch off any columns you are not interested in. Here,

however, note that Pipe Roughness and Manning's n (n) are not ticked. Click

on n and Pipe Roughness to tick them as shown below. On the Results tab

ensure the Proportional Velocity (Pro. Vel m/s) and Proportional Depth (Pro.Depth mm) fields are selected as shown below. Then click OK .

Data entryFor the first line of the spreadsheet, enter the following. Note that since pipe

1.000 is the first pipe in the line, you could use the automatic pipe numbering

facility and simply press Return instead of entering the number manually:

Pipe Pipe Fall Slope Area Time Base Pipe n US/IL US/CL Pipe


1.000 100 0.5 0.25 R 10 R 0.012 100 R COND

BUTTON

The command COND BUTTON here means that you should click the

Conduits button when the Pipe Diameter field is highlighted.

Conduits



Example 2 Page 2.5

This enables you to load or create your preferred conduit library, from which

you can select the required sections.

Setting up the LibraryWe are going to specify two different types of conduit, a built in culvert

section and a pipe for this system. This will include designing our own

section (see Appendix ii for more on this).

The Conduit Picker form defaults to the System tab which contains all 65

default conduits supplied with the software. Select the User tab; in this part of

the form you can create your own bespoke conduits. Select the Edit button

and the Conduit Designer form is loaded.

Choose the Free option and enter the following data for the first section.

Click on the Channel button and Micro Drainage automatically calculates theareas and wetted perimeter values.



Page 2.6 Example 2

This gives us a standard trapezoidal section. However, note the connection

height: 600mm. Although our specified height is 1 metre, to allow for a

proper simulation of extreme conditions within Simulation, where pipes are

to be connected to the system we need to ensure that the flow does not come

in above our prescribed level for normal flows.

Note: The Open Section box is ticked to indicate we have created an open

section.

The next section is one you can create yourself. Highlight the next row on the

spreadsheet and choose the Create option. Then select Define.

Enter the following data for the section:

Click OK and the section data are entered onto the spreadsheet. You can use

the forward slash and backward slash keys to create the Free symbol in theSymbol column. Note, however that the connection height (measured

between the pipes invert and the soffit of the upstream pipe) defaults to the

height of the section. You will need to alter this from 1 metre to 600mm.

Next, we require a U-shaped section. Enter a width of 500mm, a height of

1000mm and a connection height of 600mm. Then choose Free again and

click the U Shape button to calculate the variables for the section.



Example 2 Page 2.7

We now have sufficient sections for our demonstration. They will be saved as

part of the .mdx file the next time you save. Alternatively, the sections can be

saved as Example2.secx and opened for other projects. Select OK for the

Conduit Designer form and return to the Conduit Picker form.

Specifying a sectionSpecify the first section simply by highlighting it and clicking OK . Note that

the section is shown by the value -1. This indicates that it is a conduit taken

from your own library, rather than the default. See Appendix ii for more

details.

For pipe 1.001 enter the following:



1.001 50 0.3 0.25 R R

Hitting Return instructs System 1 to repeat the last value for Pipe diameter;

thus section -1 is chosen again.

Adding a branchWe now wish to specify a pipe branch line discharging into the channel. The

data are:



2.000 20 R 50 0.5 R R 0.6 100 R R

This time, hitting Return gives us a pipe diameter value of 300mm.

For the third section in the channel we want to put in a culvert, we can use

one of the predefined culverts in the software. We need to add more fields to

the spreadsheet to select one.



Page 2.8 Example 2

Select Preferences button on the Network Details tool bar and click on the

Input tab. Check the boxes for Section Type, Connection Height (C.Height)

and Conduit Symbol and then click OK .

Enter the pipe details as shown below:

Pipe Pipe Fall Slope Area Time Base Pipe n US/IL Section Type C. Height US/CL Conduit Pipe

No. length [m] [1:x] Entry Flow Rough [m] [m] [m] Symbol DIA

1.002 100 R R 0.5 600 Culvert R R R

We will specify neither Fall nor Slope. In the Section Type field, click on the

dropdown menu and select the 600 Culvert, this refers to the height of the

culvert in mm. The software chooses the smallest width culvert that can take

the flow (900mm) and displays it in the Pipe DIA column. The Help on

culverts and other section types can be found by pressing the F1 key.

Note: The cursor is automatically moved into the US/CL column when you

press Enter in the Area column since this is not the head of a branchline.

Step back to the Section Type column and select the required section from

the drop down menu.

System 1 calculates the minimum slope required for the culvert to

accommodate the flow. However, the branch - pipe 2.000 - is now definedwith a connection height of 700mm. This gives us a backdrop of 100mm,

since we specified a connection height for the conduit sections of 600mm.

The backdrop falls within the minimum backdrop height of 200mm specified

in Design Criteria. System 1 therefore corrects the slope for pipe 2.000 from

50 to 40. The warning bar at the foot of the spreadsheet notifies you of the

change. Switch to Longsections to see the effect of this:



Example 2 Page 2.9

The dotted line indicates the connection height specified (600mm), whereas

the solid yellow line depicts the top of the channel at a height of 1 metre. The

culvert 1.002 therefore connects at the level of the dotted line, as does the

incoming branch 2.000. Note also that the hydraulic grade line (the

approximate water level) is below the 600mm connection height.

Calculating flow capacityFinally, input the data for pipe 1.003:

Pipe Pipe Fall Slope Area Time Base Pipe n US/IL Section Type C. Height US/CL Conduit Pipe

No. length [m] [1:x] Entry Flow Rough [m] [m] [m] Symbol DIA

1.003 100 0.5 3 0.012 600 Culvert R R R

Note: As with pipe 2.000 you will need to use the cursor keys to step back

to the Manning’s n column. You will now be able to enter the required

Manning's n.

With a substantially increased area, the flow is too great for a culvert of the

same size. System 1 therefore increases the width of the culvert to 1200mm.



Page 2.10 Example 2

For this example we will make the final section open. To find a suitable

section from our own conduit file, highlight the pipe diameter field again and

click the Conduits button.

With a flow/capacity ratio of 1.031, which is 3 per cent greater than thecapacity of section -3, the section is greyed out since it cannot accommodate

the flow. You are left with the choice of the remaining two sections.

Section -1 has a ratio suggesting it will probably flow deeper than our

prescribed maximum of 600mm. Therefore click on section -2, with its

flow/capacity ratio of 0.317, and then click OK .

Section -2 is accepted, accommodating the flow of 1021.9 l/s at a depth of564mm.

Note: Even though section -2 appears in its place on the spreadsheet, the

calculations to give the values above will not be made until you have hit

Return or moved the cursor off the row.

SimulationWhile System 1 provides a snapshot of the flows through the system, and

ensures the optimum specification for the return period, it does not provide

true backwater analysis. For real-time representation of the hydraulic grade

lines, this type of system should be analysed within the Simulation module.

When you have completed Example 3 (Schedules) and Example 7

(Simulation) of this manual, or if you are already familiar with the

Simulation module, you can proceed to generate true hydraulic grade lines

for this system using the following steps.

Enter cover levelsEnter a cover level of 102m for all sections and pipes within the network.

Then save the file as Example2.mdx.



Example 2 Page 2.11

SchedulesOpen the Network menu, select Outfall Details and enter the values as

follows:

Click OK . System 1 automatically schedules the network. To view the

Schedules, from the Network Details form click on the Schedules button.

Schedules

Note: Between open sections there are no manholes. If required a manhole

can be added by changing the US Connection type from Junction to Open

Manhole and by entering a diameter into the US/MH Diam/Len column.

Save the file.



Page 2.12 Example 2

Module Selector

Select Module Selector from the Window menu. Click on the Simulation iconto add the module. Menus within the program will update to display all

available options for the Simulation module.

Running SimulationClick OK at the Simulation Criteria and set the program to analyse At Fine

time step from the Analyse menu.

Real Time Backwater Analysis Call up the Longsections. The red line is an envelope of maximum water

levels. Now animate the moving water levels as the storm passes through the

system. The envelope of maximum water levels may be printed through the

Plot module and it is a far more detailed analysis than the static levels

available through the Modified Rational Method.

The network may also be tested for 10, 20, 30 etc. year storms to observe it

overloading and flooding. Example 7 is recommended for those who wish tomaster Simulation.






Newbury RG14 1BD Open channel Design





Design Criteria for Storm












Time Area Diagram for Storm

Time

(mins)

Area

(ha)

Time

(mins)

Area

(ha)

Time

(mins)

Area

(ha)

0-4 3.116 4-8 1.373 8-12 0.011

Total Area Contributing (ha) = 4.500

Total Pipe Volume (m³) = 244.509


PN Length

(m)

Fall

(m)

Slope

(1:X)

I.Area

(ha)

T.E.

(mins)

Base

Flow (l/s)

k

(mm)

n HYD

SECT

DIA

(mm)

S1.000 100.000 0.500 200.0 0.250 5.00 10.0 0.012 \/ -1

S1.001 50.000 0.300 166.7 0.250 0.00 0.0 0.012 \/ -1

S2.000 20.000 0.500 40.0 0.500 5.00 0.0 0.600 o 300

S1.002 100.000 0.136 735.3 0.500 0.00 0.0 0.600 600 [] 900

S1.003 100.000 0.500 200.0 3.000 0.00 0.0 0.012 \/ -2


PN Rain

(mm/hr)

T.C.

(mins)

US/IL

(m)

Σ I.Area

(ha)

Σ Base

Flow (l/s)

Foul

(l/s)

Add Flow

(l/s)

Vel

(m/s)

Cap

(l/s)

Flow

(l/s)

S1.000 85.88 5.70 100.000 0.250 10.0 0.0 10.2 2.39 1466.8 78.4

S1.001 83.80 6.02 99.500 0.500 10.0 0.0 18.5 2.62 1606.8 142.0

S2.000 89.86 5.13 100.000 0.500 0.0 0.0 18.3 2.49 176.2 139.9

S1.002 74.62 7.68 99.200 1.500 10.0 0.0 47.0 1.00 462.0 360.1

S1.003 72.10 8.22 99.064 4.500 10.0 0.0 133.3 3.07 3228.7 1022.1






Newbury RG14 1BD Open channel Design




Conduit Sections for Storm


NOTE: Diameters less than 66 refer to section numbers of hydraulic

conduits. These conduits are marked by the symbols:- [] box

culvert, \/ open channel, oo dual pipe, ooo triple pipe, O egg.

Section numbers < 0 are taken from user conduit table

Section

Number

Conduit

Type

Major

Dimn.

(mm)

Minor

Dimn.

(mm)

Side

Slope

(Deg)

Corner

Splay

(mm)

4*Hyd

Radius

(m)

XSect

Area

(m²)

-1 \/ 250 1000 70.0 1.033 0.614

-2 \/ 1700 1000 1.508 1.050

Free Flowing Outfall Details for Storm

Outfall

Pipe Number

Outfall

Name

C. Level

(m)

I. Level

(m)

Min

I. Level

(m)

D,L

(mm)

W

(mm)

S1.003 S 101.000 98.564 98.000 1800 0



Example 3 Page 3.1


Example 3 – System1Schedules, Longsections,

Plan & 3D Graphics



Page 3.2 Example 3

IntroductionIn this example we are going to use the Micro Drainage Schedules module to

input manhole data in detail. The data for this example is contained in the file

Example3.mdx. This can be found in the \Micro Drainage 2014\Data directory.

Loading SchedulesThe Schedules module is incorporated in System 1. Open System 1 using

your favourite Windows method. As usual, System 1 presents you with the

Open options box.

The box gives you the option to select the last file you saved or you can open

an existing file. Double click Open Existing File and go to the \Micro

Drainage 2014\Data directory and open Example3.mdx.

Select the Outfall Details option from the Network menu and enter the outfalldetails as shown overleaf.

When you have checked that the data are correct click OK and return to the

Network Details. Input the data as shown for cover levels.



Example 3 Page 3.3

To see the Schedules spreadsheet click the Schedules button.

Schedules

Click the Schedules button again to return to the standard Network Details spreadsheet. Input the data as shown for cover levels. Move down the column

as you enter the data by using the down keyboard arrow. When complete

return to the Schedules table to see the results below.

Schedules automatically assigns a number to each manhole. You will note

that the figures in the Depth column are shown in green. This is because the

values are less then prescribed cover of 0.9m (values that are twice the

prescribed cover will also be displayed in green). Entering the cover levels

will rectify this.

Manhole SchedulesTo view the Manhole Schedule, select Manhole Schedule from the Results

menu or click the Manhole Schedule icon on the toolbar if you have added it.

Manhole Schedule

LongsectionsWithin Longsections, another key feature of Schedules is demonstrated.

Click the Show pipe bounds button.

Show pipe bounds



Page 3.4 Example 3

Note the purple and red lines, which delineate the upper and lower

boundaries for the network. The upper boundary (in purple) is dictated by the

required cover level of 0.900; the lower boundary (in red) is set by the

minimum outfall established in Design Criteria - in this case, 95.000m.

Intermediate ground levelsSchedules gives you the facility to examine intermediate ground levels, using

the GL 1/3 (m) and GL 2/3 (m) columns.

To test this resource return to the Schedules Network Details, click on the GL

1/3(m) column for pipe 1.000 and enter a value of 99.500. Enter a value of

100.000 for GL 2/3 (m), a warning appears in the Warning box at the foot of

the screen due to you do not having the prescribed cover.

This facility is particularly useful in instances where the line crosses an area

of uneven cover, such as a ditch. Schedules allows you to enter the data, but

warns you of the hazard. To see the effect, go to Longsections.



Example 3 Page 3.5

Changing manhole shapesYou can change the shape of the manholes from circular (set as default) to

rectangular, by simply specifying the Diameter/Length and Width of the

manholes. Click on the US/MH Diam/Len (mm) column for pipe 1.000 andkey in 1000 for the length and now click on US/MH Width (mm) column and

key in 750 for the Width. The value for the diameter of 1050 (mm)

disappears. Schedules shows the values in red, because you have specified

them rather than allowing the program to calculate automatically.

Note: The manhole diameters are designed in accordance with the

specifications in the Manhole size library. The option to Edit/Create a

Manhole Size library can be found in the Design Criteria form.

Making the Earth moveWithin Schedules you have the facility to achieve a 'virtual' shift in the

location of true North. This resource is actually designed to make site work

easier by eliminating the need for complex Ordnance Survey coordinates and

orienting the site around a convenient local point, such as a site base line.

Within Example3 we shall use the following coordinates:



Page 3.6 Example 3

Enter these figures by selecting Manhole Coordinates from the Network

menu.

Match boxWhen you click OK , you are warned that your coordinates do not match the

pipe lengths.

In fact, the downstream Northing for 1.002 should have been 249864.400.

Normally the coordinates take precedence in a design. As the warning box

says, you can alter the pipe lengths to suit the coordinates. Click Repair

Lengths and click OK to the message advising you what has happened. Open

the Storm Network Details spreadsheet and you will see that the length of

1.002 has been reduced from 85m to 84.6m - a difference of 0.4m, matching

exactly the error in our coordinates.

However, in this instance it is the ground that is wrong, not the pipe. Re-open

the Manhole Coordinates and enter the correct downstream Northing for pipe

1.002. Click OK and once again select the Repair Lengths option. A look at

the Network Details confirms pipe 1.002 now has the correct length.



Example 3 Page 3.7

Oriental setting Next choose Setting Out Information from the Results menu. With the True

Coordinates button selected, you can see that the system is actually oriented

at a significant angle away from true North; hence the elaborate coordinates.

Clearly, at midnight on a rainswept site, figures of this complexity do not

make the site manager's job easier. To redefine the orientation, select Site

Location from the Site menu and enter the coordinates for Manhole 1 and set

the Orientation to True - in this case, 20 degrees.

Click OK and return to the Setting Out Information. If you now choose the

Site Coordinates option, you will see that the orientation is now true North



Page 3.8 Example 3

and that the figures have been greatly simplified; they are all relative to

manhole 1.



Example 3 Page 3.9

Network PlanWith coordinates in place you can now view a plan view of the network.

Click the Plan icon:

Plan

The plan view of the network allows you to examine manholes and pipes "in

situ".

View Options

Drop down the View Options button menu and ensure the Display Manholes

and Display Pipe Numbers buttons are depressed.



Page 3.10 Example 3

Right click anywhere on the drawing and select Band Zoom.

Click and hold down the left mouse button and drag the mouse to define a

‘banding’ region. Release the button to Zoom to the region chosen.

The Pan option allows you to move the area you are viewing by dragging it.

Alternatively you may also use the Wheel on your mouse to real time zoom.

Use Previous and Extents buttons to switch between magnifications.



Example 3 Page 3.11

3D World ViewA full 3D graphical representation of your network is available in all modules

that have the Plan view.

Like the Plan the World View is based on manhole coordinates and

represents the true state of the world. Pipes without coordinates will have

default coordinates applied so they can be drawn on Plan and in 3D. This is

indicated on the Plan by the rings around each manhole. If the coordinates

and lengths do not match the pipes would be shown as dotted lines. As with

the other views right-clicking on a pipe or manhole and selecting Properties

will pop-up relevant information.

Select 3D World View from the Graphics menu or using the icon on the Plan

View tool bar.

Display World View

The World View will appear showing a full 3D model of the network and

ground.

The compass on the left gives you the ability to move around the network and

zoom into areas. Look around your system using the compass andinstructions overleaf.



Page 3.12 Example 3

In the upper toolbar there are a number of options allowing you to alter or

add to the items displayed.

View Options

Display Pipes / Manholes

These buttons switch the pipes and or manholes on and off.

Display Sky

This switches on a sky background. If switched off the background is left black.

Display Branch Indicators

A flag is drawn at the first pipe in each branch. The integer part of the pipe is

shown in blue on the flag. A flag is also drawn at each outfall position. In this

case the branch number is drawn in green.



Example 3 Page 3.13

Ground Style

No Ground switches the ground profile off. The remaining three options

change the way the profile is drawn. The Ground may be drawn as Solid,

Wireframe or Transparent. The latter option allows the pipes to be seen

through the ground. The Ground is coloured from dark green through to light

green and then grey as the level increases.

Selection Set

By selecting this option it is possible to view only those pipes in the current

Selection Set. The pipes that are not in the selection set are displayed in a

greyed out manner.

Manhole Colours

By default manholes are shown in grey and all outfalls are shown in green.

The Cover Level option colour codes the manholes depending on their cover

level.

The levels associated with each colour can be seen on the Display Settings.

The Depth view colours each manhole according to depth. The depths

associated with each colour can be seen on the Display Settings.

The Connection option displays manholes in red if the connecting pipes are

within a pre-determined angle of each other. The angle can be set from

Display Settings.



Page 3.14 Example 3

Pipe Colours

By default the main line is drawn in yellow and branch lines are displayed in

cyan. The Diameter view colours pipes depending on their size (diameter).

The diameters associated with each colour can be seen on the Display

Settings.

Display Settings

The Display Setting window shows the various colour settings used in the

various graphical displays. Each colour can be user defined. Select the Pipes

Screen colour and the select a blue from the pallet.

Screen Defaults

Select Screen Default to return the Display Settings to the standard colours.

Save

Saves the current view to disk as a graphic file.

Print

Open a Print Preview of the World View which can be sent to a printer.



Example 3 Page 3.15

View Tab

Wireframe Pipes / Manholes

Pipes and manholes can be drawn as solid or wireframe.

Ground Overlay

If a background image is available from the Plan it may be merged with or

drawn in lieu of the ground profile. Select the On Ground option to merge the

image with the existing ground colour. Alternatively select Instead of Ground

to replace the standard ground colouring with the map image.

Polygon Detail Change the detail level of the drawing elements. Lower levels will increase

frame rates on slower machines. This setting only affects solid polygons.

Wireframe elements are always drawn at Low detail.



Page 3.16 Example 3

Model Tab

Overlay Detail

Specify the size in pixels of the overlay map. Larger values make the image

clearer but use more memory and will reduce frame rate.

Horizontal Compression

The Horizontal compression scales the XY axis of the model to accentuate

falls.

Scale All Elements

With this option switched off only the pipe coordinates are scaled. Pipe and

Manhole dimensions are enlarged so they may be easily seen. This should be

taken into account if pipe clashes are being checked. Switch this option on to

show all the elements of the model in true scale (pipes become oval). For

most purposes this option can be left switched off.

Use TIN Ground ModelIf a triangulation data set is available you may switch between a full

triangulated terrain model and the default ground generated from manhole

cover level only.

Use Flat Shading

By default the terrain model is smooth shaded. Flat shading may be more

appropriate if the terrain contains sharp edges (e.g. curbs).



Example 3 Page 3.17

Rebuild Changing options on the Model tab will not automatically modify the model.

Click this button to rebuild the model with the new options.

+ and - Buttons Rebuilds the model but moves the limits of those pipes included. Use + and –

to change the limits of the model slightly.

Saving Schedules as text Schedules gives you the option to save your work as text, for use within a

word processing package. This is particularly useful for producing high

quality proposals and presentations. To do this, simply choose Save ASCII

Manhole Schedules from the File menu. The Save ASCII dialogue box

appears. Key in the title of your choice and click Save.

Note: You cannot open this file from within Micro Drainage. To view your

work, use any popular word processing package, e.g. Microsoft Word,

WordPerfect, Lotus WordPro etc.

Alternatively click on the Schedules spreadsheet with the right mouse button.

The Export menu is displayed.

From here you can choose to Print the data, save it as a .csv, .pdf, html or

Excel format. This facility is available from all of the results spreadsheets

throughout the suite.



Page 3.18 Example 3

Longsection plotsWe will now examine the use of the output of longsection images. The

Longsection module is embedded into System 1, Channel and Simulation.

Go to the File menu and select Plot Longsections. The Plot Preview form will

open.

The tabs on the left allow you to specify the parameters for the printouts.

The Plot Settings tab displays the variables used to batch the pipes for each

drawing. It allows you to choose which pipes are to be plotted and whether

you want to include branch lines in your selection. You can print the network

with the Hydraulic Grade Lines, which will show the Proportional Depth of

water in the pipes. The network can also be printed in Normal view (drawn

uphill from left to right) or Handed view (downhill from left to right).

Note: To change the page orientation, open Page Setup from the File menu

and select Landscape under Orientation.



Example 3 Page 3.19

The Plot to Printer tab determines the drawing format. A margin is drawn oneach page. The margin is applied around the edge of the page and between

the drawings if more than one drawing is plotted per page. The number of

drawings high/wide allows you to determine how many drawings across and

down the page are to be included in each plot.

Pages to Span specify the number of horizontal pages to be used to give the

overall plot.

Note: If you make any changes to the setup tabs then you must click

Update Preview for the changes to take effect.

The Plot to DXF tab lets you print your Longsection to DXF format.

Another facility available is the Plot Designer.



Page 3.20 Example 3

The Plot Designer allows you to add data to the drawings. Click the Plot

Setup icon in the lower toolbar.

Plot Designer

The Plot Designer will appear.

To add the data you require just drag it across from the data table to the top

or the bottom of the designer and the print preview will automatically update.You can also change the colours. When you have the relevant data displayed

you can save your layout for future designs.





West Street Schedules / Longsections

Newbury RG14 1BD Plan / 3D



XP Solutions Network 2014.1


Design Criteria for Example3












Network Design Table for Example3

PN Length

(m)

Fall

(m)

Slope

(1:X)

I.Area

(ha)

T.E.

(mins)

Base

Flow (l/s)

k

(mm)

HYD

SECT

DIA

(mm)

1.000 26.000 1.000 26.0 0.250 5.00 10.0 0.600 o 150

1.001 50.000 1.667 30.0 0.500 0.00 0.0 0.600 o 225

2.000 20.000 0.250 80.0 0.010 5.00 0.0 0.600 o 100

3.000 35.500 0.473 75.1 0.020 5.00 0.0 0.600 o 100

1.002 85.000 0.850 100.0 0.250 0.00 0.0 0.600 o 300


PN Rain

(mm/hr)

T.C.

(mins)

US/IL

(m)

Σ I.Area

(ha)

Σ Base

Flow (l/s)

Foul

(l/s)

Add Flow

(l/s)

Vel

(m/s)

Cap

(l/s)

Flow

(l/s)

1.000 5.00 5.22 100.000 0.250 10.0 0.0 0.0 1.98 35.0 13.4

1.001 5.00 5.57 98.925 0.750 10.0 0.0 0.0 2.40 95.3 20.2

2.000 5.00 5.39 100.000 0.010 0.0 0.0 0.0 0.86 6.8 0.1

3.000 5.00 5.67 100.000 0.020 0.0 0.0 0.0 0.89 7.0 0.3

1.002 5.00 6.57 97.183 1.030 10.0 0.0 0.0 1.57 111.1 23.9










Manhole Schedules for Example3


MH

Name

MH

CL (m)

MH

Depth

(m)

MH

Connection

MH

Diam.,L*W

(mm)

PN

Pipe Out

Invert

Level (m)

Diameter

(mm)

PN

Pipes In

Invert

Level (m)

Diameter

(mm)

Backdrop

(mm)

1 101.250 1.250 Open Manhole 1000 x 750 1.000 100.000 150

2 101.126 2.201 Open Manhole 1200 1.001 98.925 225 1.000 99.000 150

3 101.240 1.240 Open Manhole 1200 2.000 100.000 100

4 102.000 2.000 Open Manhole 1200 3.000 100.000 100

5 101.359 4.176 Open Manhole 1200 1.002 97.183 300 1.001 97.258 225

2.000 99.750 100 2367

3.000 99.527 100 21446 98.500 2.167 Open Manhole 1500 OUTFALL 1.002 96.333 300










PIPELINE SCHEDULES for Example3

Upstream Manhole


PN Hyd

Sect

Diam

(mm)

MH

Name

C.Level

(m)

I.Level

(m)

D.Depth

(m)

MH

Connection

MH DIAM., L*W

(mm)

1.000 o 150 1 101.250 100.000 1.100 Open Manhole 1000 x 750

1.001 o 225 2 101.126 98.925 1.976 Open Manhole 1200

2.000 o 100 3 101.240 100.000 1.140 Open Manhole 1200

3.000 o 100 4 102.000 100.000 1.900 Open Manhole 1200

1.002 o 300 5 101.359 97.183 3.876 Open Manhole 1200

Downstream Manhole

PN Length

(m)

Slope

(1:X)

MH

Name

C.Level

(m)

I.Level

(m)

D.Depth

(m)

MH

Connection

MH DIAM., L*W

(mm)

1.000 26.000 26.0 2 101.126 99.000 1.976 Open Manhole 1200

1.001 50.000 30.0 5 101.359 97.258 3.876 Open Manhole 1200

2.000 20.000 80.0 5 101.359 99.750 1.509 Open Manhole 1200

3.000 35.500 75.1 5 101.359 99.527 1.732 Open Manhole 1200

1.002 85.000 100.0 6 98.500 96.333 1.867 Open Manhole 1500










Setting Out Information - True Coordinates (Example3)


PN USMH

Name

Dia/Len

(mm)

Width

(mm)

US Easting

(m)

US Northing

(m)

Layout

(North)

1.000 1 1000 750 557102.000 249708.000

1.001 2 1200 557110.900 249732.400

2.000 3 1200 557108.000 249779.400

3.000 4 1200 557161.400 249767.200

1.002 5 1200 557128.000 249779.400

PN DSMH

Name

Dia/Len

(mm)

Width

(mm)

DS Easting

(m)

DS Northing

(m)

Layout

(North)

1.002 6 1500 557128.000 249864.400










Setting Out Information - Site Coordinates (Example3)


PN USMH

Name

Dia/Len

(mm)

Width

(mm)

US Easting

(m)

US Northing

(m)

Layout

(North)

1.000 1 1000 750 0.000 0.000

1.001 2 1200 0.018 25.972

2.000 3 1200 -18.782 69.146

3.000 4 1200 35.570 75.946

1.002 5 1200 0.012 75.987

PN DSMH

Name

Dia/Len

(mm)

Width

(mm)

DS Easting

(m)

DS Northing

(m)

Layout

(North)

1.002 6 1500 -29.060 155.860

Free Flowing Outfall Details for Example3

Outfall

Pipe Number

Outfall

Name

C. Level

(m)

I. Level

(m)

Min

I. Level

(m)

D,L

(mm)

W

(mm)

1.002 6 98.500 96.333 95.000 1500 0











1

1.000

150

26.0

1 0 1 .

2 5 0

9 9 .

5 0 0

1 0 0 .

0 0 0

1 0 0 .

0 0 0

9 9 .

0 0 0

26.000

2

1.001

225

30.0

1 0 1 .

1 2 6

9 8 .

9 2 5

9 7 .

2 5 8

50.000

5

1 0 1 .

3 5 9

5

1.002

300

100.0

1 0 1 .

3 5 9

9 7 .

1 8

3

9 6 .

3 3

3

85.000

6

9 8 .

5 0 0

MH Name

PN

Dia (mm)

Slope (1:X)

Cover Level (m)

Invert Level (m)

Length (m)

MH Name

PN

Dia (mm)

Slope (1:X)

Cover Level (m)

Invert Level (m)

Length (m)

Datum (m)92.000

Ver Scale 250

Hor Scale 1200

Datum (m)91.000

Ver Scale 250

Hor Scale 1200



Example 4 Page 4.1


Example 4 – System1Foul Sewer Design with Schedules



Page 4.2 Example 4

Introduction This example details the design of a complete foul sewer network with

schedules using both the Main Drainage and Fixture Unit methods. This

Micro Drainage resource also aids the drafting and production of contractdocuments.

Open System 1 and at the Open screen select New Foul Main Drainage.

Design CriteriaThe Design Criteria window appears with default values set to produce the

design flows required for gravity sewers on residential developments of 4000

l/unit dwelling/24 hours in accordance with Sewers for Adoption.

Enter the additional data as shown and click OK .



Example 4 Page 4.3

Pipeline DetailsThe Foul Network Details spreadsheet now appears. Enter the data for the

following network:

Pipe Pipe Fall Slope Area Houses Base Pipe US/IL US/CL Pipe

no length [m] [m] Flow Rough [m] [m] DIA

1.000 26 R 80 R 58 5 1.500 100 101.100 R

R 25 R 75 R 26 101.200 R

2.000 89 R 45 R 15 R R 100 101.250 R

R 54 R 50 R 22 100.925 R

3.000 25 R 25 R 36 R R 100 101.145 R

1.002 52 R 75 R 29 100.525 R

R 54 R 75 3.2 97.500 R

Here pipes 1.000 to 1.002 serve a housing development. Pipe 1.003 serves an

industrial development. Therefore, the industrial flow has been specified in

litres/second/hectare and the domestic flow has been input in terms of the

number of houses contributing.

It is assumed you have to meet an existing system which is at 95m AOD. In

order to make sure our outfall hits 95m, select Outfall Details from the

Network menu, enter the following additional data and click OK .

Click Full Optimise to improve the design and save your work as Example4.



Page 4.4 Example 4

Optimise has re-designed the network to produce the optimum cover at 0.9m

throughout the network and also a minimum Full Bore Velocity of 0.75

m/sec for each pipe. To provide a self-cleansing regime within foul gravity

sewers, the minimum flow velocity should be 0.75 m/sec at one third design

flow. Optimise has the ability to re-design the network so that it achieves

0.75 m/sec at one third design flow.

Select the optimise to P.Vel at 1/3 Flow option on the toolbar as shown

below.

Then click the Full Optimise button.



Example 4 Page 4.5

The results table shows that the minimum of 0.75 m/sec hasn't been achieved

in all cases. Pipes 1.000, 2.000, 2.001 and 3.000 all have a Proportional

Velocity of less than 0.75 m/sec at 1/3 design flow.

Pipe 1.000 is a 150mm pipe with 58 connections (houses). It has been laid at

a slope of 1:150 in accordance with Sewers for Adoption.

Pipes 2.000 and 2.001 are 100mm pipes with more than 10 connections. They

have been laid at a slope of 1:80 in accordance with BS EN 752.

Pipe 3.000 is also a 100mm pipe with more than 10 connections and is also

subject to the minimum slope (1:80) requirements of BS EN 752. Optimise

has increased the slope for this pipe to 1:40.3 to maintain 0.9m cover.

Optimise has combined minimum velocity rules, minimum slope

recommendations and minimum cover requirements to produce an acceptable

design.

Note: See also Help – System 1 – Optimise

Click Save to save the new design.



Page 4.6 Example 4

SchedulesSelect Manhole Schedule from the Results menu. System 1 has automatically

designed manhole sizes in accordance with the specification set in the

Manhole Size library.

A look at Longsections will show you that the network has been designed

satisfactorily.

You should now have a complete drainage design ready for the production of

contract documents.

Discharge Unit MethodsA second version of Foul can be accessed within System 1 that allows a

network to be designed by specifying a number of discharge units in lieu of

houses. Both the BS 8301 and EN 752 methodologies are supported.

From the Site menu select the Network Manager option and change the

Network Type to Foul – Unit as shown below. Rename the network Foul –

Unit in the Name column and then close the form.



Example 4 Page 4.7

At the Design Criteria form select the BS 8301 option and make sure all the

other data is as shown.

Click OK to the Design Criteria and the Network Details will appear.

The houses entered for the Main Drainage method have been converted to

units at a rate of 14 units per house.

Change optimse to P.Vel at 1/3 Flow again and click Optimise to re-design

the network.



Page 4.8 Example 4

On inspection the results show that the Fixture Unit method produces

different results to the Main Drainage method. The Fixture Unit method is

more applicable to smaller sites (less than 300 houses) whilst the Main

Drainage is more applicable to larger sites. The Fixture Unit method shouldalso be used on sites where there is a mixture of commercial, industrial and

residential properties.

Finally we will demonstrate how the EN 752 method can be used. Select

Design Criteria from the Network menu.

Change the Unit Calculation Method to be used to EN 752 and set the

Frequency Factor (EN 752 Only) to 0.5. This is a typical frequency factor to be used for dwellings as stated in table C.1 (BS EN 752).

Click OK to the Design Criteria and the Network Details will appear. Upon

examining the results you will see that no conversion from houses to units

has occurred when using the EN 752 method.

For this site there are roughly 12 units per dwelling based on the typical

values of discharge units (DU) in table C.2 (BS EN 752).



Example 4 Page 4.9

Enter the Units for each pipe as shown below.

Click the Full Optimise button to optimise the network to proportional

velocity at 1/3 design flow.

The Results now show the system re-designed to achieve proportional

velocity at 1/3 design flow. Where this cannot be achieved the minimumslope recommendations and minimum cover requirements have been applied

to produce an acceptable design.

On sites where there is a mixture of commercial, industrial and residential

properties a Frequency Factor (kDU) can be applied per pipe in accordance

with Table C.1 (BS EN 752).



Page 4.10 Example 4

To specify a Frequency Factor per pipe select Preferences from the toolbar.

Go to the Input tab and tick the Freq Factor option.

Click OK and the network details will now show an additional column

allowing a Frequency Factor (kDU) to be set per pipe.

PrintingThis follows the same procedure as the previous example.



Example 4 Page 4.11

Combining Storm and Foul flowsMicro Drainage gives you the facility to analyse simultaneous Storm and

Foul flows through a network. To do this, select Network Manager from the

Site menu. Test Combined Sewer can be selected from the Toolbar. A copyof the existing network is created as a Storm network or vice versa if a Storm

network that you are copying. You are then prompted to enter the Design

Criteria for your Storm or Foul flow. Clicking OK presents you with a

Network Details spreadsheet, which analyses the dry weather flow condition.

Note: In fact, a combined system would usually be analysed first within the

System 1 module as a Storm file. You can enter the Foul flow in the Design

Criteria window; it is specified in litres/second/hectare. Although this

figure is only an approximation, it is suitable for combined analysis since it

represents only a small percentage of the total flow. For more detailed

analysis of dry weather flow in particular, you can then transfer the data to

Foul as described above. This enables you to specify the foul sewage in

greater detail and to observe the proportional velocities of flow through the

system when it is not raining.



XP Sol ut i ons Page 12

J acobs Wel l Exampl e 4

West St r eet Syst em 1 - Foul Sewer Desi gn

Newbur y RG14 1BD wi t h Schedul es

Dat e 26/ 02/ 2014 Desi gned by XP Sol ut i ons

Fi l e Exampl e4. mdx Checked by

XP Sol ut i ons Net wor k 2014. 1

FOUL SEWERAGE DESI GN

Desi gn Cr i t er i a f or Foul - Mai n

©1982- 2014 XP Sol ut i ons

Pi pe Si zes STANDARD Manhol e Si zes STANDARD

I ndust r i al Fl ow ( l / s/ ha) 1. 00 Add Fl ow / Cl i mat e Change ( %) 20

I ndust r i al Peak Fl ow Fact or 3. 00 Mi ni mum Backdr op Hei ght ( m) 0. 200

Fl ow Per Per son ( l / per / day) 222. 00 Maxi mum Backdr op Hei ght ( m) 1. 500

Persons per House 3. 00 Mi n Desi gn Dept h for Opt i mi sat i on (m) 0. 900

Domest i c ( l / s/ ha) 0. 00 Mi n Vel f or Aut o Desi gn onl y ( m/ s ) 0. 75

Domest i c Peak Fl ow Fact or 6. 00 Mi n Sl ope f or Opt i mi sat i on ( 1: X) 500

Desi gned wi t h Level Sof f i t s

Network Desi gn Tabl e f or Foul - Mai n

PN Length

(m)

Fall

(m)

Slope

(1:X)

Area

(ha)

Houses Base

Flow (l/s)

k

(mm)

HYD

SECT

DIA

(mm)

1. 000 26. 000 0. 173 150. 0 0. 000 58 5. 0 1. 500 o 150

1. 001 25. 000 0. 402 62. 2 0. 000 26 0. 0 1. 500 o 150

2. 000 89. 000 1. 113 80. 0 0. 000 15 0. 0 1. 500 o 100

2. 001 54. 000 0. 675 80. 0 0. 000 22 0. 0 1. 500 o 100

3. 000 25. 000 0. 620 40. 3 0. 000 36 0. 0 1. 500 o 100

1. 002 52. 000 1. 963 26. 5 0. 000 29 0. 0 1. 500 o 1501. 003 54. 000 0. 500 108. 0 3. 200 0 0. 0 1. 500 o 225

Network Resul t s Tabl e

PN US/IL

(m)

Σ Area

(ha)

Σ Base

Flow (l/s)

Σ Hse Add Flow

(l/s)

P.Dep

(mm)

P.Vel

(m/s)

Vel

(m/s)

Cap

(l/s)

Flow

(l/s)

1. 000 100. 050 0. 000 5. 0 58 1. 5 95 0. 78 0. 71 12. 6 9. 2

1. 001 99. 877 0. 000 5. 0 84 1. 8 79 1. 13 1. 11 19. 6 10. 7

2. 000 100. 250 0. 000 0. 0 15 0. 1 26 0. 52 0. 74 5. 8 0. 8

2. 001 99. 138 0. 000 0. 0 37 0. 3 41 0. 68 0. 74 5. 8 2. 1

3. 000 100. 145 0. 000 0. 0 36 0. 3 34 0. 86 1. 05 8. 2 2. 0

1. 002 98. 413 0. 000 5. 0 186 2. 7 79 1. 74 1. 71 30. 2 16. 3

1. 003 96. 375 3. 200 5. 0 186 4. 6 130 1. 17 1. 10 43. 9 27. 8










Manhol e Schedul es f or Foul - Mai n


MH

Name

MH

CL (m)

MH

Depth

(m)

MH

Connection

MH

Diam.,L*W

(mm)

PN

Pipe Out

Invert

Level (m)

Diameter

(mm)

PN

Pipes In

Invert

Level (m)

Diameter

(mm)

Backdrop

(mm)

1 101. 100 1. 050 Open Manhol e 1200 1. 000 100. 050 150

2 101. 200 1. 323 Open Manhol e 1200 1. 001 99. 877 150 1. 000 99. 877 150

3 101. 250 1. 000 Open Manhol e 1200 2. 000 100. 250 100

4 100. 925 1. 787 Open Manhol e 1200 2. 001 99. 138 100 2. 000 99. 138 100

5 101. 145 1. 000 Open Manhol e 1200 3. 000 100. 145 100

6 100. 525 2. 113 Open Manhol e 1200 1. 002 98. 413 150 1. 001 99. 475 150 1063

2. 001 98. 463 1003. 000 99. 525 100 1063

7 97. 500 1. 125 Open Manhol e 1200 1. 003 96. 375 225 1. 002 96. 450 150

8 97. 000 1. 125 Open Manhol e 1200 OUTFALL 1. 003 95. 875 225










PI PELI NE SCHEDULES f or Foul - Mai n

Upst r eam Manhol e


PN Hyd

Sect

Diam

(mm)

MH

Name

C.Level

(m)

I.Level

(m)

D.Depth

(m)

MH

Connection

MH DIAM., L*W

(mm)

1. 000 o 150 1 101. 100 100. 050 0. 900 Open Manhol e 1200

1. 001 o 150 2 101. 200 99. 877 1. 173 Open Manhol e 1200

2. 000 o 100 3 101. 250 100. 250 0. 900 Open Manhol e 1200

2. 001 o 100 4 100. 925 99. 138 1. 687 Open Manhol e 1200

3. 000 o 100 5 101. 145 100. 145 0. 900 Open Manhol e 1200

1. 002 o 150 6 100. 525 98. 413 1. 963 Open Manhol e 12001. 003 o 225 7 97. 500 96. 375 0. 900 Open Manhol e 1200

Downst r eam Manhol e

PN Length

(m)

Slope

(1:X)

MH

Name

C.Level

(m)

I.Level

(m)

D.Depth

(m)

MH

Connection

MH DIAM., L*W

(mm)

1. 000 26. 000 150. 0 2 101. 200 99. 877 1. 173 Open Manhol e 1200

1. 001 25. 000 62. 2 6 100. 525 99. 475 0. 900 Open Manhol e 1200

2. 000 89. 000 80. 0 4 100. 925 99. 138 1. 687 Open Manhol e 1200

2. 001 54. 000 80. 0 6 100. 525 98. 463 1. 963 Open Manhol e 1200

3. 000 25. 000 40. 3 6 100. 525 99. 525 0. 900 Open Manhol e 1200

1. 002 52. 000 26. 5 7 97. 500 96. 450 0. 900 Open Manhol e 1200

1. 003 54. 000 108. 0 8 97. 000 95. 875 0. 900 Open Manhol e 1200

Fr ee Fl owi ng Out f al l Det ai l s f or Foul - Mai n

Outfall

Pipe Number

Outfall

Name

C. Level

(m)

I. Level

(m)

Min

I. Level

(m)

D,L

(mm)

W

(mm)

1. 003 8 97. 000 95. 875 95. 000 1200 0





West Street System 1 - Foul Sewer Design

Newbury RG14 1BD with Schedules





F1

F1.000

225

134.6

1 0 1 .

1 0 0

9 9 .

9 7 5

9 9 .

7 8 2

26.000

F2

F1.001

225

65.5

1 0 1 .

2 0 0

9 9 .

7 8 2

9 9 .

4 0 0

25.000

F6

F1.002

225

18.7

1 0 0 .

5 2 5

9 9 .

1 5 9

9 6 .

3 7 5

52.000

F7

F1.003

300

108.0

9 7 .

5 0 0

9 6 .

3 0 0

9 5 .

8 0 0

54.000

F8

9 7 .

0 0 0

F3

F2.000

150

150.0

1 0 1 .

2 5 0

1 0 0 .

2 0

0

9 9 .

6 0

7

89.000

F4

F2.001

150

145.0

1 0 0 .

9 2 5

9 9 .

6 0

7

9 9 .

2 3

4

54.000

F6

1 0 0 .

5 2 5

MH Name

PN

Dia (mm)

Slope (1:X)

Cover Level (m)

Invert Level (m)

Length (m)

MH Name

PN

Dia (mm)

Slope (1:X)

Cover Level (m)

Invert Level (m)

Length (m)

Datum (m)91.000

Ver Scale 250

Hor Scale 2500

Datum (m)93.000

Ver Scale 250

Hor Scale 2500





West Street System 1 - Foul Sewer Design

Newbury RG14 1BD with Schedules





F5

F3.000

150

40.3

1 0 1 .

1 4 5

1 0 0 .

0 9 5

9 9 .

4 7 5

25.000

F6

1 0 0 .

5 2 5

MH Name

PN

Dia (mm)

Slope (1:X)

Cover Level (m)

Invert Level (m)

Length (m)

Datum (m)92.000

Ver Scale 250

Hor Scale 2500



Example 5 Page 5.1


Example 5 - Source ControlDesign of a storm water storage lake



Page 5.2 Example 5

IntroductionIn this example we are going to work with the Source Control module to

design a tank/pond to serve as a landscaping water feature.

Design criteria• The tank/pond shall provide sufficient storage to limit the run-off

from a 26.9ha (paved area) site to 1300 l/s during a storm of a 100

year return period for both summer and winter storms.

• No drainage point (or top of embankments) is to be lower than500mm above the 100 year storm top water level.

• The overflow should be capable of passing a storm of a 1000 year

return period without the water level rising to within 200mm of the

top of the embankment.

The following picture shows a permanent water feature with 1.5m available

for storage:

Loading Source ControlFollow your preferred procedure for opening Source Control.

Before proceeding with a design it is useful to obtain an estimate of the

storage requirements in order to establish the parameters within which we

will be working. Therefore at the Source Control Open screen, choose Quick

Storage Estimate.



Example 5 Page 5.3

Quick Storage EstimateEnter the data as shown in the example below - some of the figures are

default values. When you are satisfied that the data are correct, click Analyse.

Source Control tells you that it is performing full routing calculations. The

following information box gives you the results:

Make a note of these parameters and click OK . The Global Variables appear

to begin a more detailed design.



Page 5.4 Example 5

Global VariablesCheck that the options shown match the entries shown on the example below.

If they do not, you can select them by using the mouse and clicking on the

arrows at the side of each box, or by using Tab and the keyboard arrows.

Rainfall & Network DetailsClick OK and Source Control opens the Rainfall & Network Details form:

We are going to run both Summer and Winter storms so make sure they are

both selected.

Note: The Cv value for winter is higher than for summer as UCWI is onaverage 50mm higher in winter.



Example 5 Page 5.5

The program assumes no upstream network unless a Storage Volume is

entered. If a storage volume is entered the other details can be entered which

the software uses to calculate the relationship between discharge and

proportional cross sectional area which may affect the Inflow Hydrograph if

there is significant upstream storage.

Enter the data as shown on the previous page - again using Tab and the

arrows or the mouse, according to your preference - and click OK .

Time Area DiagramYour next screen will be the Time Area Diagram spreadsheet. Enter the data

as shown in the right-hand column. To do this, simply highlight each box by

clicking or using the keyboard arrows and then keying in the value. Then

click OK .

Note: In a real project, Time/Area details saved in the System1 module (for

storm networks) under the File menu may be loaded into the above

spreadsheet. Click the Import button to search for files with the .tadx or.tad extension.



Page 5.6 Example 5

Plan Area of Pond Next you will see the Tank or Pond dialogue box:

After entering the Cover Level and Invert Level you can select the depth

increment required or type in only the heights at which the shape of the pondchanges. For this example click 0.1 button to set the depth increment at 0.1m.

You can enter the Area at each depth increment using the Repeat button as

required. However, for this example, enter 4250m² at depth 0.0m. Click the

calculator button and the Shape Calculator form appears. We will use this to

set the Side Slope at 1:4. We could also use the calculator to set the volume.

Note: Shape Calculator will set the side slope or volume for the entire

depth if one cell is selected or the highlighted section if more than onecell is selected.



Example 5 Page 5.7

If we click on each area cell the available volume is displayed in the bottom

left hand corner, for 1.5 m depth this is within our Quick Storage Estimate

range. When you are satisfied the data are correct, click OK .

Note: Scale Factor enables you to adjust the values of the data without re-entering the entire array. Simply enter the increment by which you wish

to increase or decrease the values and click Scale.

Setting ParametersSource Control next moves to the Weir Outflow Control dialogue box. We

will use the Calculator to size the weir based on the required outflow so click

the Calculator icon and enter the details as shown.



Page 5.8 Example 5

A weir width of 415mm is suggested. Click Apply to accept this size, enter

the other weir values as shown below and click OK .

Repeat this procedure with the Weir Overflow Control dialogue box.

Click OK and then hit the Go button in the toolbar.

Run Analysis

The drop down arrow allows you to choose the increment at which to analyse

the structure. The default is the finest increment.



Example 5 Page 5.9

Summary of ResultsSource Control performs the final routing calculations, presenting you with a

request to save the data. Click Yes and save the data as Example5. At the

conclusion of the Save procedure Source Control presents you with thesummary of results for the 100 year return period for both summer and winter

storms:



Page 5.10 Example 5

Full routing tablesTo view a detailed result, click the Hydrograph Tables icon in the toolbar.

Hydrograph Tables

Source Control opens the Hydrograph Tables, beginning with a Winter storm

of 120 minutes duration as this is the critical storm.

Use the scroll bar to the right of the table to view the effects of the storm in

its entirety. The Storm Selector allows the summer/winter analysis of any of

the storm durations to be viewed.



Example 5 Page 5.11

Graphs Next, select the Graphs icon.

Graphs

Source Control displays the Graphs screen.

Once again, you can choose to view either summer or winter and you can

change the storm duration using the Storm Selector. You will note also that

Source Control presents you with several options for viewing the graphs

themselves. Select these simply by clicking on each graph icon on the Graph

toolbar – turn on all the options to see the layout above.

Note - window management: For easy switching between resultswindows, you can use the Tile or Cascade commands under the Window

menu. As set out in Example 1, you can re-size the windows according to

preference.



Page 5.12 Example 5

AnimationSource Control allows you view your results in the form of an animated

simulation of a storm. To experiment with this, click on the Animation icon.

Animation

A Video Controls box appears which features icons that replicate the

functions of a standard media player. Click Play.

The Animation also gives you the option to view either summer or winter

storms. Select 120 min Winter from the Storm Selector . The drawing features

a red disk, which signifies the critical level for the design. An animated blue

disk indicates the level during the course of the storm.

To view the Trace option, ensure the button is depressed and press Play again, you will see the level animated in pale blue, giving you a time elapsed

picture of the storm.



Example 5 Page 5.13

Press Play again and pause the storm when the timer reaches 76 minutes. You

can now use the Forward and Rewind buttons to watch the flow minute-by-

minute. To re-start the animation at any point, simply press Stop, followed by

Play.

PrintingTo print, hit the Print icon.

Print

The Print dialogue box appears.

These options are self-explanatory; you choose the options you would like to

print by clicking in the appropriate box. Click the Update Preview button to

see a print preview. When you are satisfied with the selected options click the

printer icon at the top of the form to send the job to the printer.



Page 5.14 Example 5

Testing overflowsBefore proceeding to look at the results in detail, it is appropriate now to test

the overflow for capacity.

Close all the results forms down except the Summary of Results. The

Window menu will help you to identify forms that are still open.

From Table 7.2. Ciria Book 14 (based on ''Floods and reservoir safety, an

engineering guide, Institution of Civil Engineers'') let us assume that a breach

of the reservoir will pose negligible risk to life and cause limited damage.

This will require the overflow to be tested for a 1000 year return period

(annual probability of 0.1%).

Select Rainfall Details from the Edit menu.

Source Control returns you to the Rainfall and Network Details dialogue box.

Change the return period from 100 to 1000 years and click OK .

You will notice that as soon as you have clicked OK the software will re-

analyse the data and update the Summary of Results. This is because the

default settings in Preferences are set to Maintain Results. If you prefer to usethe Go button to run the analysis you can select the Preferences from the File

menu and change the Analysis to User .

Click the Save icon to save the file as Example5. Source Control will

automatically replace the old example with the new. You will note that the

summary of results shows a maximum depth of 1.786m, which is still within

our 1.8m limit (i.e. 200mm below the embankment) but the Status column is

displaying Flood Risk . The margin for Flood Risk warning can also be editedvia Preferences. Remember that this is a test only for the capacity of the

overflow; if it were inadequate we would increase the length, not the storage.





West Street Source Control

Newbury RG14 1BD Storm Water Storage Lake


File Example5.srcx Checked by

XP Solutions Source Control 2014.0 (Beta 2)

Summary of Results for 100 year Return Period


Storm

Event

Max

Level

(m)

Max

Depth

(m)

Max

Control

(l/s)

Max

Overflow

(l/s)

Max

Σ Outflow

(l/s)

Max

Volume

(m³)

Status

15 min Summer 100.937 0.937 641.1 0.0 641.1 4399.9 O K

30 min Summer 101.151 1.151 872.9 0.0 872.9 5528.4 O K

60 min Summer 101.290 1.290 1035.7 0.0 1035.7 6285.7 O K

120 min Summer 101.349 1.349 1108.2 0.0 1108.2 6616.2 O K

180 min Summer 101.346 1.346 1103.9 0.0 1103.9 6596.2 O K

240 min Summer 101.320 1.320 1072.1 0.0 1072.1 6453.5 O K

360 min Summer 101.255 1.255 994.4 0.0 994.4 6096.1 O K

480 min Summer 101.191 1.191 919.4 0.0 919.4 5748.1 O K

600 min Summer 101.133 1.133 852.5 0.0 852.5 5432.6 O K

720 min Summer 101.081 1.081 794.5 0.0 794.5 5154.0 O K960 min Summer 100.993 0.993 699.4 0.0 699.4 4691.5 O K

1440 min Summer 100.864 0.864 567.6 0.0 567.6 4027.6 O K

2160 min Summer 100.737 0.737 447.6 0.0 447.6 3391.1 O K

2880 min Summer 100.652 0.652 372.5 0.0 372.5 2973.4 O K

4320 min Summer 100.542 0.542 282.3 0.0 282.3 2442.5 O K

5760 min Summer 100.473 0.473 229.8 0.0 229.8 2113.1 O K

7200 min Summer 100.424 0.424 195.1 0.0 195.1 1885.6 O K

8640 min Summer 100.387 0.387 170.1 0.0 170.1 1714.5 O K

10080 min Summer 100.358 0.358 151.3 0.0 151.3 1579.9 O K

15 min Winter 101.031 1.031 740.5 0.0 740.5 4893.4 O K

30 min Winter 101.249 1.249 986.7 0.0 986.7 6061.3 O K

60 min Winter 101.420 1.420 1196.2 0.0 1196.2 7012.7 O K

120 min Winter 101.460 1.460 1247.1 0.0 1247.1 7242.3 O K

180 min Winter 101.429 1.429 1208.2 0.0 1208.2 7068.8 O K

240 min Winter 101.379 1.379 1144.7 0.0 1144.7 6781.6 O K360 min Winter 101.275 1.275 1018.3 0.0 1018.3 6206.5 O K

480 min Winter 101.185 1.185 911.8 0.0 911.8 5710.6 O K

Storm

Event

Rain

(mm/hr)

Flooded

Volume

(m³)

Discharge

Volume

(m³)

Overflow

Volume

(m³)

Time-Peak

(mins)

15 min Summer 98.681 0.0 4907.9 0.0 37

30 min Summer 64.789 0.0 6451.1 0.0 47

60 min Summer 40.510 0.0 8144.3 0.0 66

120 min Summer 24.461 0.0 9849.6 0.0 100

180 min Summer 17.964 0.0 10851.2 0.0 132

240 min Summer 14.342 0.0 11551.9 0.0 166

360 min Summer 10.418 0.0 12587.5 0.0 232

480 min Summer 8.302 0.0 13374.2 0.0 296

600 min Summer 6.956 0.0 14007.1 0.0 358

720 min Summer 6.017 0.0 14539.4 0.0 422

960 min Summer 4.784 0.0 15407.1 0.0 546

1440 min Summer 3.456 0.0 16684.2 0.0 792

2160 min Summer 2.493 0.0 18097.6 0.0 1160

2880 min Summer 1.975 0.0 19115.3 0.0 1520

4320 min Summer 1.421 0.0 20598.5 0.0 2256

5760 min Summer 1.124 0.0 21759.5 0.0 2960

7200 min Summer 0.936 0.0 22656.8 0.0 3688

8640 min Summer 0.806 0.0 23404.9 0.0 4424

10080 min Summer 0.710 0.0 24033.6 0.0 5152

15 min Winter 98.681 0.0 5488.7 0.0 37

30 min Winter 64.789 0.0 7238.9 0.0 51

60 min Winter 40.510 0.0 9133.5 0.0 68

120 min Winter 24.461 0.0 11033.9 0.0 104180 min Winter 17.964 0.0 12155.8 0.0 140

240 min Winter 14.342 0.0 12940.6 0.0 174

360 min Winter 10.418 0.0 14100.6 0.0 242

480 min Winter 8.302 0.0 14981.9 0.0 308












Storm

Event

Max

Level

(m)

Max

Depth

(m)

Max

Control

(l/s)

Max

Overflow

(l/s)

Max

Σ Outflow

(l/s)

Max

Volume

(m³)

Status

600 min Winter 101.107 1.107 823.3 0.0 823.3 5292.6 O K

720 min Winter 101.040 1.040 750.2 0.0 750.2 4939.3 O K

960 min Winter 100.933 0.933 637.0 0.0 637.0 4381.1 O K

1440 min Winter 100.785 0.785 492.0 0.0 492.0 3631.4 O K

2160 min Winter 100.650 0.650 370.8 0.0 370.8 2962.9 O K

2880 min Winter 100.564 0.564 299.7 0.0 299.7 2548.2 O K

4320 min Winter 100.459 0.459 219.7 0.0 219.7 2048.3 O K

5760 min Winter 100.395 0.395 175.4 0.0 175.4 1749.8 O K

7200 min Winter 100.350 0.350 146.6 0.0 146.6 1546.3 O K


Storm

Event

Rain

(mm/hr)

Flooded

Volume

(m³)

Discharge

Volume

(m³)

Overflow

Volume

(m³)

Time-Peak

(mins)

600 min Winter 6.956 0.0 15691.0 0.0 374

720 min Winter 6.017 0.0 16287.3 0.0 438

960 min Winter 4.784 0.0 17259.7 0.0 564

1440 min Winter 3.456 0.0 18692.3 0.0 810

2160 min Winter 2.493 0.0 20270.6 0.0 1180

2880 min Winter 1.975 0.0 21411.1 0.0 1544

4320 min Winter 1.421 0.0 23077.3 0.0 2268

5760 min Winter 1.124 0.0 24371.2 0.0 3008

7200 min Winter 0.936 0.0 25376.7 0.0 3744











Model Details


Storage is Online Cover Level (m) 102.000

Tank or Pond Structure

Invert Level (m) 100.000

Depth (m) Area (m²) Depth (m) Area (m²) Depth (m) Area (m²) Depth (m) Area (m²) Depth (m) Area (m²)

0.000 4250.0 0.600 4822.7 1.200 5431.7 1.800 6076.8 2.400 6758.1

0.100 4342.9 0.700 4921.7 1.300 5536.7 1.900 6187.8 2.500 6875.2

0.200 4436.9 0.800 5021.7 1.400 5642.7 2.000 6299.9

0.300 4531.8 0.900 5122.7 1.500 5749.7 2.100 6412.9

0.400 4627.8 1.000 5224.7 1.600 5857.7 2.200 6527.0

0.500 4724.8 1.100 5327.7 1.700 5966.7 2.300 6642.0

Weir Outflow Control

Discharge Coef 0.544 Width (m) 0.415 Invert Level (m) 100.000

Weir Overflow Control











Event: 120 min Winter




Example 6 Page 6.1


Example 6 - Source ControlDesign of a storm water tank sewer



Page 6.2 Example 6

IntroductionIn this example we are going to design a tank sewer (circular pipe) to limit

the discharge from a 0.45ha site to 16 litres/second during storms of 30 year

return period. We will use a Hydro-Brake

®

as our control.

Quick Storage EstimateFollow the procedure set out in Example 5 to choose the Quick Storage

Estimate option.

In this example we are going to use FEH rainfall data that can be obtained

from the FEH CD produced by the Institute of Hydrology (now known as the

Centre for Ecology and Hydrology). The FEH data for this example iscontained in the file Example6.csv . This file can be found in your \Micro

Drainage 2014\Data directory. Change the Region to FEH Rainfall by

selecting it from the drop down list and click the Browse button to the right

of the Site Location box to load in the Example6.csv file (FEH Rainfall

models can also be loaded in .xml file format). Enter the remaining data as

below and click Analyse.



Example 6 Page 6.3

The results from the QSE will appear showing the storage requirements to be

between 75m³ and 114m³ for the variables stated above. The variation in

storage is dependent on the type of control, structure and the shape of the

storage. It is therefore very important to analyse the actual storage structure,

as approximations may produce significant error. For example, do not assumea constant flow rate through an orifice - it varies greatly with depth.

Click OK on the results form and the Global Variables will be opened.

Global VariablesAt the Source Control Global Variables box, select the options as shown,

using the mouse or tab and the keyboard arrows.



Page 6.4 Example 6

Rainfall and Network DetailsClick OK to the Global Variables and the Rainfall And Network Details

dialogue box is presented. All the data entered for the Quick Storage

Estimate will automatically be pulled across. We intend to run both Summerand Winter storms again so make sure they are selected and click OK .

Note: No entries are required for the Network Details column in this

instance. This is because routing the flow through the pipe network does

not normally result in a significant reduction in the storage facility size, for

two reasons:

• The total storage in the pipe network is small compared with moststorage facilities.

•

The peak flow in the pipe network does not usually coincide with

the peak storage in the storage facility, i.e. when the storage facility

is full, the pipe network is not.



Example 6 Page 6.5

Time Area DiagramAt the Time Area Diagram, enter the following data:

0 to 4 minutes 0.3

4 to 8 minutes 0.15When you have checked that the data are correct, click OK .

Pipe Details Now enter the Pipe Details as shown below, then click OK .

Note: 50m of 1.5m pipe gives 88.4m³ of storage - between 75m³ and

114m³, as calculated within the Quick Storage Estimate.



Page 6.6 Example 6

Outflow ControlYou will now see the Hydro-Brake

® Outflow Control dialogue box. Enter the

data as shown.

The outflow curve is generated automatically. Click OK to accept the data

and click the Go button.



Example 6 Page 6.7

ResultsYour Summary of Results should be as below and will show the results for

both the summer and winter storms. From these you can see the maximum

storage occurs for the 30 minute winter storm duration. The depth of waterabove the outfall invert of the tank sewer is 1.709m. The maximum discharge

is 15.6 l/s.



Page 6.8 Example 6

AnimationOnce again you have an animation facility with which to examine the levels

at each stage of a storm. Choose 3D Animation from the View menu.

Again you have the option to view either summer or winter storms. Select 30

Winter (the critical storm) from the Storm Selector .

It is possible to move around the structure by clicking on the compass. The

full list of motion controls are discussed in Example 3.



XP Solutions Page 9



Newbury RG14 1BD Storm Water Tank Sewer


File Example 6.srcx Checked by




Storm

Event

Max

Level

(m)

Max

Depth

(m)

Max

Control

(l/s)

Max

Volume

(m³)

Status

15 min Summer 101.807 1.407 14.4 66.5 O K

30 min Summer 101.885 1.485 14.7 71.4 O K

60 min Summer 101.859 1.459 14.6 69.8 O K

120 min Summer 101.763 1.363 14.2 63.6 O K

180 min Summer 101.685 1.285 13.9 58.1 O K

240 min Summer 101.612 1.212 13.6 52.9 O K

360 min Summer 101.480 1.080 13.0 43.3 O K

480 min Summer 101.364 0.964 12.5 34.9 O K

600 min Summer 101.262 0.862 12.1 27.7 O K

720 min Summer 101.170 0.770 11.6 21.7 O K960 min Summer 101.004 0.604 10.9 12.4 O K

1440 min Summer 100.668 0.268 10.2 1.9 O K

2160 min Summer 100.400 0.000 7.9 0.0 O K

2880 min Summer 100.400 0.000 6.3 0.0 O K

4320 min Summer 100.400 0.000 4.7 0.0 O K

5760 min Summer 100.400 0.000 3.8 0.0 O K

7200 min Summer 100.400 0.000 3.2 0.0 O K

8640 min Summer 100.400 0.000 2.8 0.0 O K

10080 min Summer 100.400 0.000 2.5 0.0 O K

15 min Winter 101.963 1.563 15.0 75.8 O K

30 min Winter 102.109 1.709 15.6 82.4 O K

60 min Winter 102.094 1.694 15.5 81.8 O K

120 min Winter 101.918 1.518 14.8 73.3 O K

180 min Winter 101.787 1.387 14.3 65.1 O K

240 min Winter 101.670 1.270 13.8 57.1 O K360 min Winter 101.470 1.070 13.0 42.6 O K

480 min Winter 101.302 0.902 12.2 30.5 O K

Storm

Event

Rain

(mm/hr)

Flooded

Volume

(m³)

Discharge

Volume

(m³)

Time-Peak

(mins)

15 min Summer 95.811 0.0 80.6 19

30 min Summer 56.492 0.0 95.5 32

60 min Summer 33.309 0.0 112.8 52

120 min Summer 19.640 0.0 132.1 84

180 min Summer 14.419 0.0 146.2 120

240 min Summer 11.580 0.0 156.6 152

360 min Summer 8.502 0.0 172.5 218

480 min Summer 6.828 0.0 184.3 282

600 min Summer 5.760 0.0 194.4 344

720 min Summer 5.013 0.0 203.0 404

960 min Summer 4.013 0.0 216.8 520

1440 min Summer 2.933 0.0 237.5 750

2160 min Summer 2.144 0.0 260.5 0

2880 min Summer 1.716 0.0 278.0 0

4320 min Summer 1.279 0.0 310.7 0

5760 min Summer 1.038 0.0 336.2 0

7200 min Summer 0.882 0.0 357.3 0

8640 min Summer 0.773 0.0 375.6 0

10080 min Summer 0.691 0.0 391.8 0

15 min Winter 95.811 0.0 90.4 19

30 min Winter 56.492 0.0 107.0 32

60 min Winter 33.309 0.0 125.3 56

120 min Winter 19.640 0.0 148.0 92180 min Winter 14.419 0.0 163.7 128

240 min Winter 11.580 0.0 175.6 164

360 min Winter 8.502 0.0 192.8 232

480 min Winter 6.828 0.0 206.7 298












Storm

Event

Max

Level

(m)

Max

Depth

(m)

Max

Control

(l/s)

Max

Volume

(m³)

Status

600 min Winter 101.157 0.757 11.6 20.9 O K

720 min Winter 101.023 0.623 11.0 13.3 O K

960 min Winter 100.714 0.314 10.2 2.7 O K

1440 min Winter 100.400 0.000 7.8 0.0 O K

2160 min Winter 100.400 0.000 5.7 0.0 O K

2880 min Winter 100.400 0.000 4.6 0.0 O K

4320 min Winter 100.400 0.000 3.4 0.0 O K

5760 min Winter 100.400 0.000 2.8 0.0 O K

7200 min Winter 100.400 0.000 2.3 0.0 O K

8640 min Winter 100.400 0.000 2.1 0.0 O K10080 min Winter 100.400 0.000 1.8 0.0 O K

Storm

Event

Rain

(mm/hr)

Flooded

Volume

(m³)

Discharge

Volume

(m³)

Time-Peak

(mins)

600 min Winter 5.760 0.0 217.7 358

720 min Winter 5.013 0.0 227.3 416

960 min Winter 4.013 0.0 242.6 528

1440 min Winter 2.933 0.0 266.1 0

2160 min Winter 2.144 0.0 291.7 0

2880 min Winter 1.716 0.0 311.4 0

4320 min Winter 1.279 0.0 348.0 0

5760 min Winter 1.038 0.0 376.5 0

7200 min Winter 0.882 0.0 400.2 0











Model Details



Pipe Structure

Diameter (m) 1.500 Slope (1:X) 70.000 Length (m) 50.000 Invert Level (m) 100.400

Hydro-Brake® Outflow Control

Design Head (m) 2.200 Hydro-Brake® Type Md6 SW Only Invert Level (m) 100.000

Design Flow (l/s) 16.0 Diameter (mm) 137

Depth (m) Flow (l/s) Depth (m) Flow (l/s) Depth (m) Flow (l/s) Depth (m) Flow (l/s) Depth (m) Flow (l/s)

0.100 4.5 0.800 10.0 2.000 15.1 4.000 21.4 7.000 28.3

0.200 9.5 1.000 10.9 2.200 15.9 4.500 22.7 7.500 29.3

0.300 10.5 1.200 11.8 2.400 16.6 5.000 23.9 8.000 30.3

0.400 10.2 1.400 12.7 2.600 17.3 5.500 25.1 8.500 31.2

0.500 9.8 1.600 13.5 3.000 18.5 6.000 26.2 9.000 32.1

0.600 9.6 1.800 14.4 3.500 20.0 6.500 27.3 9.500 33.0










Event: 30 min Winter




Example 7 Page 7.1


Example 7 - SimulationSimulation of a drainage system

with tank sewers



Page 7.2 Example 7

IntroductionThe following system has been designed to illustrate a large number of

features in a small network. It should be studied closely by any user who

intends to introduce storage into a system in order to alleviate flooding.

The following facilities are demonstrated:

• Determine flooding in a system with a limited discharge.

• Identify the pipes responsible for that flooding.

• The use of online controls to improve the performance of storagetanks.

•

Pumping.• The use of additional offline controls.

• The use of looped controls.

The data for this example is contained in the file Example7.mdx. This can be

found in the \Micro Drainage 2014\Data directory.

Loading Simulation

Open Simulation using your preferred method. At the Open screen, selectOpen Existing File. The familiar Open File dialogue box now appears.

Example7.mdx should feature on the list of files, enabling you to open the

file simply by double clicking. If it is not shown, it can be found on the

installation DVD supplied. The file will be opened with the Simulation

Criteria screen.

You are now ready to commence the simulation project.



Example 7 Page 7.3

The networkWe are going to simulate the following network:

Pipes 2.000 and 3.000 have been enlarged to provide potential storage in the

system. 3.000 has no flow associated with it and is used purely as storage to

reduce the water level upstream of 1.004 and consequently reduce the flows

in 1.004 itself. The network must discharge no more than 50 l/s with no

flooding for the 30 year return period.

Flood riskSimulation allows you to preset the level at which it will warn you that there

is a serious risk of flooding. Call up the Preferences dialogue box from theFile menu.

Note: The above network is contained in the file Example7.mdx.

However if you cannot find this file, simply input the system. The

network details can be found on the output accompanying this example.

The procedure is similar to that detailed in Example 1 of this manual. Thedata is first input in the System 1 program and then Scheduled before it

can be simulated. Note that upsizing of pipes in System 1 is prevented

by setting the maximum rainfall to zero in the Design Criteria or by

using the “not allowed” auto design option (only if A.P.T. is installed).



Page 7.4 Example 7

The default value for flood warning is 300mm. The effect will be shown in

the Summary of Results. As a general rule Engineers should not design for

the water level to be immediately below the cover level.

Check the Analysis is set to Maintain Results. With this selected Simulation

will reanalyse the network automatically each time the network is edited.Summary forms will be updated without the need to close and reload them.

Simulation CriteriaAt the Simulation Criteria screen, simply alter the return period from one

year to 30 years and the MADD factor to 1. Your finished data should look as

follows:



Example 7 Page 7.5

The Water UK/WRc plc specification Sewers for Adoption 6th

Edition states

that the “system should be designed under pipe full conditions for 1, 2 or 5

years” and “designed not to flood any part of the Site for a 1:30 year return

period design storm.” In addition, local planning conditions or other

approving authorities may require a more extreme standard such as the 100year return period plus an allowance for climate change.

With the above conditions a MADD factor of 2 would not be unreasonable

but the Water Company may use their discretion to request a lower value or

0. For more information select the Help facility within Simulation Criteria.

Surcharged OutfallSelect Outfall Details from the Network menu and the following windowappears:

This facility allows you to edit the outfall details and model a tidal outfall. If

the water rises above the invert of the outgoing pipe there will be a backing

effect in the drainage system. You are able to vary the rising water level

minute by minute to model this effect in Micro Drainage. This is also usefulif the network outfalls into a pond where the top water level is higher than the

network's outfall.



Page 7.6 Example 7

The model assumes that a flap valve has been placed on the outfall to prevent

the water flowing back into the system. This example has a free outfall so

simply click Cancel and click OK on the Simulation Criteria.

AnalyseWe are now ready to analyse the flows through the network. Click the

Analyse menu. The following options appear:

You are given four choices of time interval for the analysis. While the storm

is actually only 30 minutes long, the analysis is for 60 minutes to observe the

system draining down. To run the analysis for longer, specify a Run Time inthe Simulation Criteria, for this example accept the software default.

For a detailed calculation, choose the At Fine time step option either with the

mouse or the keyboard arrows. The Progress window now appears, followed

by the Save New Data dialogue box.

Click the Save option. Simulation automatically presents you with the

Summary of Results spreadsheet. Use the scroll bar below the data to view

the Status field if it is not shown.



Example 7 Page 7.7

Whilst the network shows no flooding the pipe flow from 1.004 is 206 l/s, far

more than the 50 l/s maximum allowed.

Online ControlsA flow control can be introduced to pipe 1.004 to limit the discharge from the

network. To do this simply select the Online Controls option from the

Network menu.

Online Controls

The Online Controls spreadsheet now appears.

•

Clear deletes all the specifications for the highlighted control.• Clear All deletes all the specified controls.

Enter 1.004 in the DS Pipe Number . Select control type Pump from the

dropdown list. A constant pump rate is needed, the depth increment can be

user specified. If a Depth and a single Outflow rate are entered the program

will assume the pump requires 200mm to reach the constant flow rate which

it will then maintain up to cover level at that manhole. With this in mind

enter 0.2m and 50 l/s respectively in the first cells.Alternatively you can select a Depth Increment which will populate the

Depth column on the spreadsheet for you. You may then enter flows for each

depth increment.



Page 7.8 Example 7

When your data are as above, click OK .

As the preferences are set to Maintain Results the analysis is automatically

instigated using the last selected time increment. Alternatively if you have

chosen User from the preferences select the Go toolbar shortcut.

Run Analysis



Example 7 Page 7.9

Summary of ResultsIn the Summary of Results, the results are colour-coded:

• Pipes whose flow capacities are less than 1 are shown in blue.

•

Pipes whose flow capacities are greater than 1 are shown in red.• Pipes whose flow capacities are greater than 2 are highlighted.

The term flow capacity refers to the ratio of the flow to the full bore capacity

of the pipe.

Note: A test for overloading within System 1 would have shown different

results. Simulation takes account of manhole losses, inlet/outlet controls

and other factors to provide a more accurate representation of the realities

of fluid flow and pipe capacity. For more information on the method ofanalysis view the Help.

Simulation applies four levels of status to pipes within a network:

• Flood identifies those pipes where the water level is above the upstream

cover level.

• Flood Risk is shown when the water level rises to within a prescribed

distance from the cover level - the default freeboard value is 300mm.

•

Surcharged pipes are those where the water level is above the soffit at theupstream end of the pipe.

• OK designates a pipe where the water is at or below the soffit at the

upstream end.

Analysis of Results

In this example, although pipe 1.001 is surcharged, it is not overloaded (the

flow capacity is less than 1 and is shown in blue). It is only shown as

surcharged because its downstream pipe (1.002) is overloaded and backs-up

into 1.001.



Page 7.10 Example 7

Pipe 1.003 has surcharged to within 300mm of the cover level and is

therefore shown as Flood Risk . Pipe 1.004 has flooded because of the

restriction placed on it by the pump rate.

GraphsTo view graphs, simply click on the Graphs icon in the toolbar.

Graphs

Simulation presents you with graphic analysis for each pipe in turn.

To view each pipe, use the Select Pipe drop down at the top of the screen.

You are also able to choose whether to view Branch Lines, Selection Set,

Flow Graph, Velocity Graph, Volume Graph, Depth Graph, Rainfall Curve

on Flow Graph, Overflow Curve on Flow Graph and Infiltration Curve on

Flow Graph using the buttons on the Toolbar.



Example 7 Page 7.11

Longsections, animate Next, click on the Longsections icon in the toolbar.

Longsections

Simulation presents the longsection of the network. You can move along the

network using the scroll bar as usual, adjusting your view by choosing the

number of pipes displayed.

For the best view of the animation facility, enlarge the screen and scroll to

the end of the network. Set the number of pipes to be displayed to 5 and the

length of line 1 will be presented.

The red line indicates the highest water level during the storm and it is

already apparent that flooding occurs at the upstream end of 1.004.



Page 7.12 Example 7

AnimationWithin Simulation, the Video Controls form appears when a graphics form

that can be animated is opened, it is available from the Results menu if it has

been closed. As with Source Control these function in the same way as astandard media player:

Here again the animated red line indicates the flow and you can use the Trace

button to view a time-elapsed image.

SchematicCall up the Schematic from the Graphics menu and run the animation to view

the progress of the storm. Clicking Show Flow Direction indicates the flow

with a dotted line and direction pointer.

Note that at the peak of the flow - around 20-40 minutes into the 30 minute

storm - surcharged pipes and manholes are shown with red circles around the

manholes. Flooded parts of the system show in blue with the animation

showing how the manhole fills and floods during the storm.



Example 7 Page 7.13

Windows management within SimulationYou can have the results analysis facilities open simultaneously. As with

System 1, you can arrange them for easy switching between windows by

using the Cascade option under the Window menu. You can also switch between windows using the icons in the toolbar.

Utilising existing storageMove the Longsection so that pipes 2.000 and 2.001 are displayed. The red

maximum water line clearly shows pipe 2.000 does not fill. We are now

going to try to control the outflow from pipe 2.000 to use more of its storage.

We will assign a 150mm orifice control on pipe 2.000. However, instead of

entering the data in the usual way we can demonstrate the use of Toolbox in

the Schematic View (also available in the Plan View) as a means of

introducing controls.



Page 7.14 Example 7

Using the Schematic to introduce controlsClick on the Schematic icon to open the Schematic view. You will see that as

branch line 2 was being displayed on the Longsection the Schematic will

automatically go to the same branch. Select the Toolbox icon.

Toolbox

Make sure the Online Controls tab is selected. There is a collection of icons

representing online controls. Moving the pointer over each control causes the

name of the control to be displayed. In each case the final icon is used to

cancel any given control.

For this example we require control Orifice, which is the top left of the On-

Line icons:

Orifice

Click on this and drag it over the manhole at the outflow of 2.000 as shown

below. See also the How-Do-I: Specify a Hydro-Brake® for more information

on dragging and dropping controls.



Example 7 Page 7.15

When you release the mouse button, the Online Controls dialogue box

appears.

Enter the diameter of 150mm (0.150m) and click OK ; the Schematic shows

that a control is now present.

As Maintain Results is selected in the File Preferences the analysis is

automatically run after every edit made to your network. Open the

Longsection and once the Maintain Results has finished you can see that the

storage in pipe 2.000 has now been fully utilised. On faster PCs this will be

almost instantaneous. The next step is to try to alleviate flooding at the pump

location.



Page 7.16 Example 7

More analysisYou will notice that orifice controls on the tank sewers raise the water levels

in the tanks, making better use of their storage and reducing downstream

flows even further. Pipe 2.000 is controlled by a combination of thedownstream orifice and the rising water level in pipe 2.001.

In other words, Micro Drainage can analyse controls drowned by rising water

levels downstream. (To examine the tank sewer 2.000 on the graphs you must

examine pipe 2.000 and also the control pipe 2.001, as its upstream manhole

determines the level. Pipe 2.000 itself may show no surcharging which only

means that the water level is not above the upstream soffit of pipe 2.000).

As Simulation analyses backwater effects in all pipes including those without

controls. The downstream pipe, together with rising water levels in the

downstream system dictates the water level in the pipes.

The downstream pipe in cases without controls should be relatively long;

otherwise small changes in water levels will result in very large changes in

hydraulic gradient and/or capacities.

For these obvious reasons large short pipes are not suitable for analysiswithout controls. If you are in any doubt, inspect the results and in particular

if the unstable analysis warning appears on your results. If there are rapid and

repeated changes in the outflow graph run the analysis At 2.5 Second

Increment (Extended) by selecting it from the Analyse menu. Also refer to

Unstable Analysis in the on-line Help.

Micro Drainage also provides for a large range of online control

configurations to be used at invert levels above the control.



Example 7 Page 7.17

Overflows Next introduce an offline control in the form of a side weir in the upstream

manhole of pipe 1.004. This provides an overflow for the pumping station to

maintain a water depth of around 1.6m. To do this, call up the OfflineControls form by selecting Offline Controls from the Network menu. Offline

Controls can also be added in the same way as Online Controls on the Plan or

Schematic.

Offline Controls

In the first cell key in pipe number 1.004 and call up the control type options

as described above. Choose option Weir . When the Control Details box

appears, enter the values as shown, using tab or the mouse to move between

the boxes. Then click OK and wait for the analysis to update. The flow over

the weir is shown in the Overflow (l/s) column of the Summary of Results.



Page 7.18 Example 7

StorageIt is not always possible to discharge water from the network in this manner.

We will therefore add storage at the pump to stop the overflow activating.

Before designing the storage we need to find out how much is required. To

do this select the Preferences button on the Summary of Results toolbar. Tick

the Overflow Vol (m³) option, click Apply and then OK .

The Summary of Results now displays an Overflow Vol (m³) column, which

shows 48.139 m³ goes over the weir. There is 1.6m of usable depth below the

overflow in manhole 8. This equates to a fixed rate pond area of about 35m².

To add the pond select Pond (Tank/Storage Structure) from the Network

menu and enter the details as shown below.

Specifying 35.0 in the Area (m²) column will result in a straight sided pond

starting at the manhole invert and rising up to the cover level. Click OK . Waitfor the Summary of Results to be automatically updated.



Example 7 Page 7.19

The results show that the flooding has been cured.

Note: This is a simple case with a constant pumped flow. Source Control

may be used to estimate the storage requirement in more complex

examples. Also CASDeF can size storage for all storms in a few seconds.

Controls (loops)Finally, we will introduce a loop into the system. Open the Offline Controls

spreadsheet again and enter pipe number 2.001 in the second row. Select

control type Pipe and Loop to Pipe Number 3.000. Enter the data as shown,

click OK and run the analysis.

AnalysisLook at the graphs for pipes 2.001 and 3.000. You will see that the loop

control pipe takes a distinct "chunk" of water from pipe 2.001 and lets it flow

through 3.000. The water only flows through the looped pipe control when

the upstream manhole of 2.001 has a water depth of 0.6m above the outgoing pipe invert.



Page 7.20 Example 7

PrintingTo print your results, click on the Print icon in the toolbar. The Simulation

Print gives you a range of options:

For this final analysis select the Network Details, Simulation Criteria,

Storage Structures, Online Controls and Offline Controls from the Model tab.

From the Results tab select Summary of Results and Rainfall Profile and then

select the Update Preview button.

The selected information will now be displayed. Select the Print button to print or alternatively select Save to create an electronic copy.



Example 7 Page 7.21

APT Flood Flow & Climate Change

If this is the system you want you should also check it for all storm durations.

If you have very small controls then very long storms may be critical. If you

have APT the wizards may be used to automatically summarise the results ofall Summer and Winter storms. It is also necessary under some specifications

to determine flood flow paths and the sensitivity to climate change and these

facilities are described in Example 8.

Measured Rainfall and measured flows If you choose Rainfall Profile in the Simulation Criteria, you will be allowed

to specify up to ten hyetographs. In this instance you may use soil index and

PIMP data in lieu of Cv (the volumetric run-off coefficient).

You can then specify a different hyetograph for each pipe by entering the

hyetograph number in the Profile Number column of Rainfall Links which

can be accessed in the Network menu. You can re-run the above example

with Rainfall Profile selected in the Simulation Criteria. You have the option

to create, edit and load synthetic hyetograph and/or real world rainfall data

which the program will use for analysis.

Measured hydrographs may also be input into the system. This feature is also

used to connect upstream networks into the system. If a sub-catchment has

not been analysed it may be represented as a time/area diagram, as can an

undeveloped catchment which may need to be incorporated to determine its

effect on the network.

If you have APT the Unit Hydrograph method may be used to generate flows

from undeveloped land.



Page 7.22 Example 7

Points to rememberProbably the most common mistake to make with Simulation is to run a

hopeless case. A system that cannot take a 5 year storm will not yield

meaningful results when simulated on a 100 year return period. Some preliminary work is required.

The first step is to run option 1 of the overloaded options contained in System

1 for say a 1 year return. This will yield the diameters the pipes should have

been under normal design conditions. If a 150mm pipe should have been a

600mm pipe then there is precious little point in simulating it under extreme

conditions - it will flood!

If the capacity of the pipe is very small then storage may not be the most

economical solution. The pipe may have to be upgraded.

The program will endeavour to analyse anything you specify but only if your

approach is sensible will the results be meaningful.





West Street Simulation of a drainage

Newbury RG14 1BD system with tank sewers



XP Solutions Network 2014.0 (Beta 2)

Existing Network Details for Example7


PN Length

(m)

Fall

(m)

Slope

(1:X)

I.Area

(ha)

T.E.

(mins)

k

(mm)

HYD

SECT

DIA

(mm)

1.000 20.000 1.200 16.7 0.200 5.00 0.600 o 225

1.001 39.000 0.488 79.9 0.120 0.00 0.600 o 300

2.000 80.000 0.360 222.2 0.200 5.00 0.600 o 600

2.001 25.000 0.888 28.2 0.120 0.00 0.600 o 225

1.002 90.000 0.360 250.0 0.115 0.00 0.600 o 375

1.003 50.000 0.350 142.9 0.350 0.00 0.600 o 375

3.000 90.000 0.480 187.5 0.000 5.00 0.600 o 750

1.004 45.000 0.300 150.0 0.070 0.00 0.600 o 375

PN US/MH Name

US/CL(m)

US/IL(m)

USC.Depth

(m)

DS/CL(m)

DS/IL(m)

DSC.Depth

(m)

Ctrl US/MH(mm)

1.000 1 102.000 100.500 1.275 101.000 99.300 1.475 1050

1.001 2 101.000 99.225 1.475 100.600 98.737 1.563 1050

2.000 3 101.900 100.060 1.240 101.700 99.700 1.400 1500

2.001 4 101.700 99.700 1.775 100.600 98.812 1.563 Orifice 1500

1.002 5 100.600 98.662 1.563 100.150 98.302 1.473 1350

1.003 6 100.150 98.302 1.473 99.600 97.952 1.273 1350

3.000 7 100.400 97.950 1.700 99.600 97.470 1.380 1800

1.004 8 99.600 97.470 1.755 98.800 97.170 1.255 Pump 1800

Free Flowing Outfall Details for Example7

Outfall

Pipe Number

Outfall

Name

C. Level

(m)

I. Level

(m)

Min

I. Level

(m)

D,L

(mm)

W

(mm)

1.004 9 98.800 97.170 0.000 1800 0

Simulation Criteria for Example7

Volumetric Runoff Coeff 0.750 Foul Sewage per hectare (l/s) 0.000

Areal Reduction Factor 1.000 Additional Flow - % of Total Flow 0.000

Hot Start (mins) 0 MADD Factor * 10m³/ha Storage 1.000Hot Start Level (mm) 0 Run Time (mins) 60

Manhole Headloss Coeff (Global) 0.500 Output Interval (mins) 1

Number of Input Hydrographs 0 Number of Offline Controls 2 Number of Time/Area Diagrams 0

Number of Online Controls 2 Number of Storage Structures 1

Synthetic Rainfall Details

Rainfall Model FSR Profile Type Summer

Return Period (years) 30 Cv (Summer) 0.750

Region England and Wales Cv (Winter) 0.840

M5-60 (mm) 20.000 Storm Duration (mins) 30

Ratio R 0.400










Online Controls for Example7


Orifice Manhole: 4, DS/PN: 2.001, Volume (m³): 25.7

Diameter (m) 0.150 Discharge Coefficient 0.600 Invert Level (m) 99.700

Pump Manhole: 8, DS/PN: 1.004, Volume (m³): 49.7


Depth (m) Flow (l/s)

0.200 50.0000










Offline Controls for Example7


Pipe Manhole: 4, DS/PN: 2.001, Loop to PN: 3.000

Diameter (m) 0.225 Roughness k (mm) 0.600

Section Type Pipe/Conduit Entry Loss Coefficient 0.900

Slope (1:X) 50.0 Coefficient of Contraction 0.600

Length (m) 50.000 Upstream Invert Level (m) 100.300

Weir Manhole: 8, DS/PN: 1.004, Loop to PN: None











Storage Structures for Example7


Tank or Pond Manhole: 8, DS/PN: 1.004


Depth (m) Area (m²)

0.000 35.0










Summary of Results for 30 minute 30 year Summer (Example7)


Margin for Flood Risk Warning (mm) 300.0 DVD Status OFF

Analysis Timestep Fine Inertia Status OFF

DTS Status ON

PN

US/MH

Name

Water

Level

(m)

Surcharged

Depth

(m)

Flooded

Volume

(m³)

Flow /

Cap.

Overflow

(l/s)

Pipe

Flow

(l/s) Status

1.000 1 100.613 -0.112 0.000 0.51 0.0 58.8 OK

1.001 2 99.740 0.215 0.000 0.77 0.0 89.4 SURCHARGED

2.000 3 100.409 -0.251 0.000 0.13 0.0 54.8 OK

2.001 4 100.396 0.471 0.000 0.41 21.5 36.9 SURCHARGED

1.002 5 99.499 0.462 0.000 1.15 0.0 138.4 SURCHARGED

1.003 6 99.152 0.475 0.000 1.36 0.0 211.0 SURCHARGED

3.000 7 99.106 0.406 0.000 0.02 0.0 14.4 SURCHARGED

1.004 8 99.106 1.261 0.000 0.33 4.2 50.0 SURCHARGED










Graphs for Pipe 1.004 US/MH 8 (Example7)

30 minute 30 year Summer

Status: SURCHARGED




Example 8 Page 8.1


Example 8 - Simulation Advanced Productivity Tools & CASDeF



Page 8.2 Example 8

IntroductionThis example demonstrates the enhanced functionality of A.P.T. and

CASDeF to improve the design and productivity of a typical drainage

network.

The developed site is expected to increase the volume of discharge above the

original greenfield runoff. Therefore the allowable discharge has been limited

to QBAR (20 l/s) for the 100 year event.

The determination of QBAR and the pre-development runoff volume is

discussed in Appendix v.

The completed design must comply with Sewers For Adoption (no flooding

for a 1:30 year return period, minimum velocities, manhole sizes etc.). A

pond at the outfall will be designed for the 100 year event while discharging

no more than 20 l/s.

Finally, the system will be audited against increased rainfall to determine

sensitivity to failure under climate change. Also any on-site flooding that

occurs during this extreme event must be contained on the site and the

overland flood flow paths identified to ensure the safety of buildings.

The example follows the current requirements of ICP SUDS, SFA, CfSH and

NPPF. However the specification for each site must be approved by the

relevant statutory authorities. Other specifications and criteria may be

supported using a similar methodology, for example the Code for Sustainable

Homes requirements under Category 4: Surface Water Runoff, SUR 1 are

based on the ICP for SUDS and therefore the same audit can be used. Risks

to pedestrians and vehicles from flood flow may also be determined but iscovered in example 14 in more detail.



Example 8 Page 8.3

The networkThe following network will be tested:

We have the opportunity of placing some of the storage mid site in pipe

1.002. This pipe has been enlarged to 1200mm. We will assess the system to

see if it is being utilised and, if not, we will design a control to make the best

use of the storage available. As we have to limit the discharge to 20 l/s we

will add a control at the upstream end of 1.007.

This design was set out using System1 and DrawNet. So far no simulationchecks have been carried out to find whether it passes the current design

specifications and good engineering practice. Before APT was available,

checks were carried out by inspection, running each storm duration

individually and analysing the huge amount of data generated by the network.

Processing the storms individually did not take a long time, but analysing the

data and finding the critical storm for the network was very time consuming,

especially if attenuation was incorporated into the design (which is the norm

in sustainable design).

APT (Advanced Productivity Tools) takes the laborious and time consuming

data collation and analysis out of the equation.

APT and CASDeF automate through a range of Wizards to analyse the

system and alter it automatically. Approximately one thousand simulations

will have been run via all the Wizards when this example has been

completed.



Page 8.4 Example 8

Loading the SoftwareOpen Network using your preferred method. At the Open screen, select Open

Existing File.

Go to the \Micro Drainage 2014\Data directory and Example8.mdx should

feature on the list of files, enabling you to open the file simply by double

clicking (please ensure it is the latest file supplied with the software). If it is

not displayed, it can be found on the installation DVD supplied.

Overview of the NetworkWe will start with a Seasonal Return Period Wizard. This Wizard will

provide a full overview of the system for all storm durations, both Summerand Winter and it will also identify the critical storm for each node

automatically.

Select Seasonal Return Period Wizard from the Wizards menu.

The Wizard will take you through a series of storyboards allowing sequential

data entry. Step 1 sets the rainfall criteria for the site. Simulation will

automatically read the rainfall data specified in the storm design.

Note that the wizard allows you to run both Summer and Winter storms.

Winter storms are very important especially when checking attenuation

designs. You should also check that the Volumetric Runoff Coefficient is at

least 0.84 for winter storms. The program gives standard defaults, but these

can be changed to suit different site conditions (please refer to Help for more

information).

Summer and Winter storms should be run for this design so make sure they

are both selected and click Next to proceed to Step 2. Specify the standardstorm durations by clicking the Default button and then Next.



Example 8 Page 8.5

Step 3 allows you to enter the Return periods. Enter the return periods as

below and click Next.

At Step 4 the Fine (recommended) time step is chosen with Dynamic Time

Step on. Click Finish.



Page 8.6 Example 8

The program starts running all nine design storms for both Summer and

Winter profiles, with six different Return Periods. That’s a total of 108

simulations.

When all the runs have been completed click Save and the Summary WizardResults along with a Storm Selector floating window will be presented. To

examine the results in full we need to add a couple of fields to the Summary

table.

Select Summary Preferences from the toolbar. Select Event and Storm Rank ,

click Apply and then OK .

Use the Storm Selector to view the results of all the simulation runs for

different return periods and storm durations.

From the Summary of Results we are interested in finding the critical storm

for each node. We can do this by sorting through all 108 storms individually

or we can simply click the Critical Storm icon, which will sift through all the

data and find the worst case for every pipe based on the Maximum WaterLevel.

Critical Storm

The summary table will now show the results below.



Example 8 Page 8.7

There is no flooding in the system for a 30 year return period but in the

absence of controls the Network is discharging at 823.2 l/s. Also note the 15

minute Winter Storm is critical for every pipe.

Tip: If the network becomes unstable, re-run the Wizard and at Step 4select the 2.5 second increment (extended) (slowest analysis). This will

run the longer storm durations at a shorter time step. For cases where the

Summary shows flooding but the water level is below the cover level you

may see an unstable analysis warning to help warn you when an extended

time step may be needed.

Click back onto the Current Storm icon and from the Storm Selector , select

the 15 minute Winter storm for the 30 year return period.

Current Storm

Storm Selector window

Bring up the 3D WorldView either from the Graphics menu or be selecting

the icon from Plan view.

3D World View

The program will generate a full 3-Dimensional representation of the

network. Click on the compass to the left to move around the network and

zoom into areas. (See Example 3 for more information on how to use all the

controls in the 3D view and also see Help).



Page 8.8 Example 8

The Video Controls form appears allowing animation of the water levels in

the pipes and manholes throughout the storm. The Storm Selector should

already be open displaying the 15 minute winter storm for the 30 year return

period. If it is not visible you can select it from the Results menu and changeit to show the above information.

Use the compass to get pipe 1.002 fully in view and press the Play button on

the Video Controls. Notice how the pipe storage is not fully utilised for the

critical storm.



Example 8 Page 8.9

CASDeF CASDeF provides solutions to hydraulic problems in the sewer system.

Normally CASDeF is used to solve flooding problems, but it has a wider

range of application.

Instead of the Engineer providing individual solutions through trial and error,

CASDeF will provide the solutions automatically and, more importantly,

quickly.

The CASDeF Controller gives the Engineer complete control over the design

and analysis processes. Any or all options may be switched off at each node

to prevent CASDeF from defining impractical solutions.

A full Audit Trail is provided enabling the Engineer to trace the decisions

made by CASDeF.

To solve individual problems, CASDeF will use a logical 3 step procedure.

Step 1 – Introduction and sizing of controls to utilise existing storage

Step 2 – Upgrading of pipe sizes where there is insufficient flow capacity

Step 3 – Introduction of Storage

In this example we are going to use CASDeF to design a hydraulic control at

the downstream end of our large tank sewer (Pipe 1.002). This will attenuate

the flow in Pipe 1.002 to utilise all the available storage.

Select Network Manager from the Site menu. We want to save the file before

running CASDeF but as yet we do not know if this will be our final solution.

You could save a revision at each change in a separate file. Alternatively, youare able to Copy the network and save revisions or scenarios in the same file

using the Network Manager functions.

Highlight Example8 and click the Copy icon in the toolbar. Rename the Copy

as Example8A. To stop CASDeF making changes to the starting network you

can turn off analysis for Example8 by clicking the Go icon so it turns red,

also turn off the Select, Move and Visible options. The Network Manager

should now look like this:



Page 8.10 Example 8

Now select CASDeF Parameters from the Site menu.

The CASDeF Parameters allow the range of design storms to be set. You can

also set design parameters such as minimum control sizes and standard pipe

increments when upsizing pipes.

Set the data as above and click OK .



Example 8 Page 8.11

Open the Network menu and select CASDeF Controller .

Switch on the Modify Control setting for pipe 1.003 and click OK . The

control upstream of pipe 1.003 will control the water levels in pipe 1.002.

To start the CASDeF run select CASDeF + Summary Wizard from the

Wizards menu. CASDeF will now design the control to fully utilise the

storage capacity of the pipe. Then it will construct a summary wizard on the

design for a full validation.

Again step through the Wizard selecting Summer and Winter storms and the

default storm durations as before and at the end of the wizard click Finish to

commence the CASDeF run. If a warning appears select No and CASDeFwill only be run on the current network

When the Wizard has finished running, the summary of results will be

displayed. Click the Critical Storm icon in the toolbar to observe the impact

of the CASDeF alterations.



Page 8.12 Example 8

Note that CASDeF has lowered the final discharge rate to 777.0 l/s, without

introducing any flooding. We must view the Audit Trail to examine the

changes made by CASDeF.

Under the Results menu in the main toolbar, select CASDeF Audit Trail.

The Audit Trail saves all the decision-making processes CASDeF used whilst

solving the problem.

Use the scroll bar at the side of the table to view the CASDeF alterations.

The grand summary is at the end of the file. CASDeF has designed a 268mm

orifice plate to make full use of the storage in Pipe 1.002.

The effect of the orifice is clearly illustrated on the 3D view. First change the

Storm Selector to view the 30 minute Winter storm. Now click on the Plan

view and click the 3D button or open the 3D from the Graphics menu.

We have used CASDeF so far to design hydraulic controls in the system and

make use of the storage capacity. This is just a small sample of its power.



Example 8 Page 8.13

We are now going to change the specification quite dramatically. The

network is currently discharging with no restrictions on the outfall. However

most sites will have some form of restricted discharge.

The final discharge through Pipe 1.007 is to be restricted to 20 l/s for the 100year return period. A storage pond at the outfall must be designed to store the

100 year event (ICP SUDS). From the previous wizard we know that the

current discharge rate for the worst case storm is 777.0 l/s. It is quite obvious

that if we cut the flow down to such a small rate flooding will occur.

Normally we would set a control to achieve our desired discharge rate and

run all the design storms to find the extent of the flooding, if any. We would

then proceed to design the storage structure and re run all the design stormsagain to prove that the system meets the new criteria.

We will set the control and solve the flooding in one operation,

demonstrating another part of CASDeF.

Before setting the control make another copy of the network called

Example8B following the same procedure as on page 8.10 but this time copy

then switch off Example8A.



Page 8.14 Example 8

Select Simulation Criteria from the Site menu and change the Return Period

(years) to 100, Storm Duration (mins) to 30 and Profile to Winter.

Then open the Online Controls and specify a Hydro-Brake® at Pipe 1.007.

Click the Calculator button and set the Design Head to 2m and the

Design Flow to 20 l/s.

Select an MD 6 from the list. This Hydro-Brake® type is not pre-initialised in

this case and it also has a good opening size of 157mm.



Example 8 Page 8.15

We must change the CASDeF Controller to set up the new specification

before we carry out the CASDeF run.

Click on the Network menu in the toolbar and select the CASDeF Controller .

Edit the CASDeF Controller to allow storage to be added at the Hydro-

Brake® location by ticking the Add Storage box for pipe 1.007 and set the

Level Not Exceed to 98.037 (2m deep).

Remember to deselect Modify Control for Pipe 1.003, as it will still be

selected from the last run.

Click OK .



Page 8.16 Example 8

We are now ready to run CASDeF again. Select CASDeF + Summary

Wizard from the Wizards menu. Set the Return Period (years) to 100 and go

through the steps as before.

CASDeF will analyse several passes to design a storage pond to alleviate theflooding.

Select CASDeF Audit Trail from the Results menu and peruse the changes

made by CASDeF.

The audit trail documents that CASDeF has added 2022m³ of storage at the

upstream end of Pipe 1.007 in the form of a pond.

Close the audit trail and open the Summary of Results to examine the effect

of adding the pond.

Notice that there are now three storms, which are critical in the network.



Example 8 Page 8.17

The critical summary confirms that the discharge has been reduced to 17.8 l/s

(below the 20 l/s target). However on inspection the Summary shows that the

water level at the pond location is 1.592m (992mm surcharged depth on pipe

1.007 plus a 600mm pipe). This is below our required water depth of 2m for

the pond which is acceptable but you may wish to adjust it.

Before continuing add a copy of the network called Example8C as on page

8.10 remembering to turn off the other networks.

To increase the water level we will reduce the size of the pond manually by

20% (0.4m/2m).

Select Pond (Tank/Storage Structure) from the Network menu.

Enter -20 in the Scale Factor box and click the Scale button. Then click OK

to accept the new pond size.

As we have used CASDeF to make the Engineering decisions for us and

changed the system, we still need to check the design to verify that it still

complies with good engineering practice in accordance with Sewers For

Adoption 7th

Edition. Additional calculations to confirm compliance with the

Interim Code of Practice have also been included.



Page 8.18 Example 8

Click on the Wizards menu in the main toolbar and from the pull down select

Design Audit Wizard.

The Design Audit Wizard will appear.

This allows you to specify up to 10 tests, ranging from Pipe Diameters to Full

Bore Velocities.

Confirm that the variables are set out as above and click Next to proceed to

Step 2. Make sure both the Summer and Winter storms are selected.

Step 3 allows you to specify the storm durations. We are going to run thestandard storm durations so click the Default button and then Next.



Example 8 Page 8.19

Step 4 allows you to set different return periods for the different design

checks. Three more audits are also available here, Surcharge, Flooding and

P. Velocity. Tick all boxes and accept the default return periods. Set the

Minimum Proportional Velocity (m/s) to 0.75 and select Next.

At Step 5 tick Use ICP SUDS to turn on the 14th

and final audit which tests

the allowable discharges for the network against the ICP SUDS specification.



Page 8.20 Example 8

Refer to Appendix v for a worked example on calculating the allowable

discharge rates.

If required the return periods and climate change allowances can be specified

as will be required for the Code for Sustainable Homes criteria. For thisexample, accept the defaults.

It is also necessary to determine the volume of runoff from the undeveloped

site during an event of 360 minute duration and 100 year return period (based

on the current ICP SUDS specifications).

Enter the discharge rates as shown and click the Calculate button. Enter the

ICP Greenfield Runoff values as shown below and click Calculate.



Example 8 Page 8.21

The undeveloped catchment discharges a volume of 1696m3

for a 360 minute

100 year return period event. If this volume discharge is exceeded for the

same storm on the developed site then 20.1 l/s will be the maximum

allowable discharge for both the 30 and 100 year events.

Click OK to apply the results of the Calculator and then proceed to the end of

the Wizard. Click Finish to run the Auditor.

When completed the Wizard presents its findings. The Summary report lists a

total of five failures across seven pipes. The system has failed on cover

levels, velocities, proportional velocities, headlosses and the ICP check.

Click the Pipes option to see where the failures have occurred.

X markers indicate that pipe 1.002 has failed on cover, velocity and

proportional velocity. Pipe 2.001 has failed on velocity. Pipe 1.007 has failed

on proportional velocity and the ICP audit and pipes 1.003 to 1.006 have

failed on manhole headlosses.

We will now examine the failures in more detail by looking at themindividually. Click the Cover Levels option on the left hand side.



Page 8.22 Example 8

Pipe 1.002 does not have the required 1.2m cover at its downstream end. This

pipe was originally oversized for the storage and again this failure can be

accepted if the structural strength and pipe surround are specified

appropriately.

The next set of failures is listed under Full Bore Velocity. Click the Full Bore

Velocity option to display the following data.

Then click on the Proportional Velocity option as this is the next failure on

the list.

Pipes 1.002 and 2.001 have not reached the minimum velocity of 1m/s Full

Bore and 1.002 and 1.007 have not reached the specified minimum

Proportional Velocity of 0.75m/s.

It is important for pipes to attain self-cleansing velocities and this particular

failure will need to be addressed. If it is not addressed silting may occur in

the pipe and consequently it may lose some of its storage capacity. Maximum

Velocity may be specified by the sewerage undertaker otherwise it will be

down to the engineer’s judgement whether this should be corrected or not.

The next set of failures is listed under Manhole Headloss. Click the Manhole

Headloss option to display the following data.



Example 8 Page 8.23

Simulation has applied a global headloss of 0.15 to all the manholes in the

network. As a general rule this value applies to pipes angled at no more than

30 degrees. However, as the network has co-ordinates specified the Auditor

has identified manholes (upstream of 1.003, 1.004, 1.005 and 1.006) where a

higher headloss would be more appropriate due to the change in flowdirection. The recommended headlosses can be applied automatically by

clicking the Update button, however doing this will invalidate the Design

Audit results.

We will return and update the headlosses after reviewing the final category,

ICP Audit.

Developing the site has increased the runoff from the predevelopment

volume of 1696 m3. This confirms that under the ICP SUDS specification the

site should not be allowed to discharge more than QBAR which is 20 l/s. If

the site had passed this test or if the discharge was very low for the 5mm testthen a higher allowable discharge could have been considered.



Page 8.24 Example 8

The Code for Sustainable Homes will require you to show the pre and post

development runoff rates and volume which are presented here, however you

must add an allowance for climate change. In addition the Minimal Discharge

Test may be used to gain extra credits.

To fix the headlosses return to the Manhole Headloss page, click the Update

button and answer Yes to the on-screen prompt. To correct the problems of

low velocities we need to change the physical properties of the pipe.

Create another copy using the Network Manager as before called

Example8D.

Select Existing Network Details from the Network menu.

Increase the fall on Pipes 1.002 and 2.001 by lifting the upstream end of pipe1.002 by 300mm and by lowering the downstream end of pipe 2.001 by

200mm. This should help the pipes to achieve self-cleansing velocity.

Also the pipe specified for 1.007 only has to convey 20 l/s maximum flow.

Alter the diameter to 300mm.



Example 8 Page 8.25

To view the four updated manhole headlosses select Manhole Headloss from

the Network menu, the updated values appear in red to indicate they have

been changed from the default value specified in the Simulation Criteria.

Close the Manhole Headloss and Network Details windows.

As we have made changes to the network we need to rerun the Design Audit

to determine if the altered system complies with good engineering practice.

Select Design Audit Wizard from the Wizards menu, re-enter the values for

the ICP SUDS step as per page 19 and click the finish button to re-run the

wizard.

When the Wizard has finished select the Pipes option again. The Summary

table indicates the system has still failed on cover for pipe 1.002 and

surcharging for pipe 1.007. This is acceptable as 1.002 is our tank sewer and

has been enlarged to provide storage and 1.007 should surcharge, as it is

where the Hydro-Brake® is located.



Page 8.26 Example 8

Pipe 1.007 also fails the ICP Audit for the Volume Balance Test which is

acceptable as QBAR was chosen as the allowable discharge.

However the Summary does not list any failures for full bore velocity,

proportional velocity and manhole headloss. The amendments we made tothe system have resulted in self-cleansing velocities in our pipes and the

network has now passed the set criteria.

In the past, Engineers had to design a system that had no flooding typically

for the 1 in 30 year event. Several specifications and regulations including

Sewers for Adoption 7th

Edition now require the Engineer to test the system

beyond failure and identify the flood flow paths.

Below is the relevant extract from Sewers for Adoption 7th

Edition.

'In designing the site sewerage and layout, Developers should also

demonstrate flow paths and the potential effects of flooding resulting from

extreme rainfall blockage, pumping station failure or surcharging in

downstream sewers, by checking the ground level around the likely points

that flow would flood from the system to identify the flood routes'.

All of these checks can be carried out in Micro Drainage. APT will execute afull Sensitivity analysis on the design and it will also indicate the location of

the failures and the sites of possible surface ponding.

Now choose the Climate Change/Sensitivity Wizard from the Wizards menu.

Step through the Wizard to Step 3 adding Default storm durations at Step 2.



Example 8 Page 8.27

The Wizard will increase/decrease the rainfall by the default percentages

shown in Step 3. National Planning Policy Framework (2012) states that

‘Local planning authorities should adopt proactive strategies to mitigate and

adapt to climate change, taking full account of flood risk’ in line with the

objectives and provisions of the Climate Change Act 2008, a value of 30% iscommonly applied.

Click Clear all and enter the data as shown below.

Proceed to the end of the wizard and click Finish.

When the Summary of Results appear it may not display the information we

require so select the toolbar Summary Preferences.

Tick the boxes as shown below, click Apply and then OK .



Page 8.28 Example 8

The Summary of Results has now been extended as specified. Click the

Critical Storm icon to identify the critical storm for each pipe.

The First Flooding column displays the event that causes first failure. The

cells with no data have no flooding for any of the increased flows.

The results indicate three pipes that are the most sensitive points in the

network as they flood with 20% additional flow. However a majority of the

system could withstand the 100 yr rp storm +30% with only minor flooding.

The data from the Sensitivity Wizard can be viewed graphically enabling you

to identify where the system may fail and the possible flood flow paths.Change the Storm Selector to 15 Winter / +30% sensitivity Flow and bring

up the 3D World View which will display a full 3D representation of the

network and ground profile.

To identify the flooding, the direction of the flood flow and where it finally

ponds select the Flood Path icon from the View Options button menu.

Flood Path

Note: This does not mean you can downsize these pipes.



Example 8 Page 8.29

Note that the ground profile has three additional colours:

The Light Blue shading marks the source point of the flooding.

The Yellow Arrows identify the route of the flooding.

The Dark Blue shading locates where the water ponds.

Note: A more detailed analysis of overland flow paths can be generated

using the FloodFlow module. See Example 14 for more details.





West Street Simulation

Newbury RG14 1BD A.P.T. and CASDeF


File Example 8.mdx Checked by


Existing Network Details for Example8D


PN Length

(m)

Fall

(m)

Slope

(1:X)

I.Area

(ha)

T.E.

(mins)

Base

Flow (l/s)

k

(mm)

HYD

SECT

DIA

(mm)

E1.000 20.000 1.200 16.7 0.250 5.00 0.0 3.000 o 225

E1.001 39.000 0.437 89.2 0.250 0.00 0.0 3.000 o 300

E2.000 25.000 0.625 40.0 0.130 5.00 0.0 3.000 o 225

E2.001 90.000 0.653 137.8 0.250 0.00 0.0 3.000 o 300

E1.002 90.000 0.360 250.0 0.240 0.00 0.0 3.000 o 1200

E1.003 50.000 0.465 107.5 0.200 0.00 0.0 3.000 o 525

E3.000 90.000 2.324 38.7 0.105 5.00 0.0 3.000 o 150

E4.000 45.000 1.390 32.4 0.136 5.00 0.0 3.000 o 225

E1.004 48.170 0.458 105.2 0.135 0.00 0.0 3.000 o 525

E1.005 21.990 0.220 100.0 0.951 0.00 0.0 3.000 o 525

E1.006 34.000 0.680 50.0 0.469 0.00 0.0 3.000 o 525

E1.007 34.000 0.222 153.2 0.900 0.00 0.0 3.000 o 300


PN US/IL

(m)

Σ I.Area

(ha)

Σ Base

Flow (l/s)

Vel

(m/s)

Cap

(l/s)

E1.000 100.507 0.250 0.0 2.51 99.9

E1.001 99.232 0.500 0.0 1.32 93.1

E2.000 99.948 0.130 0.0 1.62 64.4

E2.001 99.248 0.380 0.0 1.06 74.8

E1.002 98.295 1.120 0.0 1.94 2197.6

E1.003 97.935 1.320 0.0 1.74 376.1

E3.000 100.124 0.105 0.0 1.25 22.0

E4.000 98.860 0.136 0.0 1.80 71.6

E1.004 97.470 1.696 0.0 1.76 380.3

E1.005 97.012 2.647 0.0 1.80 390.1

E1.006 96.792 3.117 0.0 2.55 551.9E1.007 96.037 4.017 0.0 1.00 71.0










Manhole Schedules for Example8D


MH

Name

MH

CL (m)

MH

Depth

(m)

MH

Connection

MH

Diam.,L*W

(mm)

PN

Pipe Out

Invert

Level (m)

Diameter

(mm)

PN

Pipes In

Invert

Level (m)

Diameter

(mm)

Backdrop

(mm)

E1 102.000 1.493 Open Manhole 1200 E1.000 100.507 225

E2 101.000 1.768 Open Manhole 1200 E1.001 99.232 300 E1.000 99.307 225

E3 102.800 2.852 Open Manhole 1200 E2.000 99.948 225

E4 101.000 1.752 Open Manhole 1500 E2.001 99.248 300 E2.000 99.323 225

E5 100.500 2.205 Open Manhole 1800 E1.002 98.295 1200 E1.001 98.795 300

E2.001 98.595 300

E6 99.800 1.865 Open Manhole 1800 E1.003 97.935 525 E1.002 97.935 1200

E7 102.500 2.376 Open Manhole 1200 E3.000 100.124 150

E8 100.900 2.040 Open Manhole 1200 E4.000 98.860 225

E9 99.600 2.130 Open Manhole 1800 E1.004 97.470 525 E1.003 97.470 525

E3.000 97.800 150

E4.000 97.470 225

E11 100.000 2.988 Open Manhole 1500 E1.005 97.012 525 E1.004 97.012 525

E12 99.000 2.208 Open Manhole 1500 E1.006 96.792 525 E1.005 96.792 525

E13 98.500 2.463 Open Manhole 1500 E1.007 96.037 300 E1.006 96.112 525 300

EO/F 1 97.750 1.935 Open Manhole 1200 OUTFALL E1.007 95.815 300

Free Flowing Outfall Details for Example8D

Outfall

Pipe Number

Outfall

Name

C. Level

(m)

I. Level

(m)

Min

I. Level

(m)

D,L

(mm)

W

(mm)

E1.007 EO/F 1 97.750 95.815 0.000 1200 0

Simulation Criteria for Example8D

Volumetric Runoff Coeff 0.840 Additional Flow - % of Total Flow 0.000

Areal Reduction Factor 1.000 MADD Factor * 10m³/ha Storage 1.000

Hot Start (mins) 0 Inlet Coeffiecient 0.800

Hot Start Level (mm) 0 Flow per Person per Day (l/per/day) 0.000

Manhole Headloss Coeff (Global) 0.150 Run Time (mins) 60

Foul Sewage per hectare (l/s) 0.000 Output Interval (mins) 1


Number of Online Controls 2 Number of Storage Structures 1 Number of Real Time Controls 0


Rainfall Model FSR Profile Type Winter

Return Period (years) 100 Cv (Summer) 0.750


M5-60 (mm) 20.000 Storm Duration (mins) 30

Ratio R 0.400










Online Controls for Example8D


Orifice Manhole: E6, DS/PN: E1.003, Volume (m³): 104.5

Diameter (m) 0.268 Discharge Coefficient 0.600 Invert Level (m) 97.935

Hydro-Brake® Manhole: E13, DS/PN: E1.007, Volume (m³): 11.4




0.100 5.2 0.800 13.7 2.000 19.9 4.000 28.1 7.000 37.2

0.200 12.0 1.000 14.5 2.200 20.9 4.500 29.8 7.500 38.5

0.300 14.6 1.200 15.6 2.400 21.8 5.000 31.4 8.000 39.8

0.400 14.6 1.400 16.7 2.600 22.7 5.500 33.0 8.500 41.0

0.500 14.1 1.600 17.8 3.000 24.4 6.000 34.4 9.000 42.2

0.600 13.7 1.800 18.9 3.500 26.3 6.500 35.9 9.500 43.3










Storage Structures for Example8D


Tank or Pond Manhole: E13, DS/PN: E1.007



0.000 924.3








File Example8_cdf_cdf.mdx Checked by


Summary of Critical Results by Maximum Level (Rank 1) for Example8D


Simulation Criteria

Areal Reduction Factor 1.000 Additional Flow - % of Total Flow 0.000

Hot Start (mins) 0 MADD Factor * 10m³/ha Storage 1.000

Hot Start Level (mm) 0 Inlet Coeffiecient 0.800

Manhole Headloss Coeff (Global) 0.150 Flow per Person per Day (l/per/day) 0.000

Foul Sewage per hectare (l/s) 0.000


Number of Online Controls 2 Number of Storage Structures 1 Number of Real Time Controls 0


Rainfall Model FSR M5-60 (mm) 20.000 Cv (Summer) 0.750

Region England and Wales Ratio R 0.400 Cv (Winter) 0.840

Margin for Flood Risk Warning (mm) 300.0 DVD Status OFF

Analysis Timestep Fine Inertia Status OFF

DTS Status ON

Profile(s) Summer and Winter

Duration(s) (mins) 15, 30, 60, 120, 240, 360, 480, 960, 1440

Return Period(s) (years) 1, 30, 100

Climate Change (%) 0, 0, 0

PN Storm

Return

Period

Climate

Change

First X

Surcharge

First Y

Flood

First Z

Overflow

O/F

Act.

Lvl

Exc.

E1.000 15 Winter 100 0% 30/15 Summer 100/15 Winter 1

E1.001 15 Winter 100 0% 30/15 Summer 100/15 Winter 1

E2.000 15 Winter 100 0% 30/15 Summer

E2.001 15 Winter 100 0% 30/15 Summer 100/15 Summer 2

E1.002 30 Winter 100 0% 100/15 Summer

E1.003 30 Winter 100 0% 1/15 Winter 100/15 Summer 6

E3.000 15 Winter 100 0% 30/15 Summer 100/15 Summer 2

E4.000 15 Winter 100 0% 100/15 Summer

E1.004 15 Winter 100 0% 30/15 Summer

E1.005 15 Winter 100 0% 30/15 Summer

E1.006 15 Winter 100 0% 30/15 Summer

E1.007 480 Winter 100 0% 1/30 Summer

PNUS/MH Name

Water

Level(m)

Surch'ed Depth (m)

Flooded

Volume(m³)

Flow /Cap.

O'flow(l/s)

Pipe

Flow(l/s) Status

E1.000 E1 102.001 1.269 0.806 0.93 0.0 91.0 FLOOD

E1.001 E2 101.000 1.468 0.199 2.05 0.0 188.4 FLOOD

E2.000 E3 101.474 1.301 0.000 0.86 0.0 54.3 SURCHARGED

E2.001 E4 101.004 1.456 3.699 1.64 0.0 121.9 FLOOD

E1.002 E5 99.856 0.361 0.000 0.14 0.0 294.1 SURCHARGED

E1.003 E6 99.846 1.386 46.036 0.57 0.0 199.0 FLOOD

E3.000 E7 102.501 2.227 1.056 1.29 0.0 28.4 FLOOD

E4.000 E8 99.676 0.591 0.000 0.74 0.0 52.4 SURCHARGED

E1.004 E9 98.977 0.982 0.000 0.82 0.0 286.9 SURCHARGED

E1.005 E11 98.856 1.319 0.000 1.59 0.0 528.4 SURCHARGED

E1.006 E12 98.328 1.011 0.000 1.55 0.0 680.3 SURCHARGED

E1.007 E13 97.973 1.636 0.000 0.28 0.0 19.6 SURCHARGED



Example 9 Page 9.1


Example 9 – ChannelThe Backwater Step Method



Page 9.2 Example 9

IntroductionChannel is a backwater step method for determining the water levels in open

channels. It is suitable for gradually varying flows in channels of reasonably

uniform cross section where the flow is sub-critical.

Where the flow becomes super-critical (or rapid), an estimate of depth based

on stage discharge is output for the main channel. Backwater analysis is then

continued upstream when the flow becomes sub-critical (or tranquil) again.

Methodology Step methods are one of the most commonly used ways for determining

backwater curves. They calculate the water levels from station to station

where the cross sections and hydraulic characteristics are known.

Some of these methods determine the hydraulic gradient at each station and

average them, while others use the average cross sectional area of the stations

to determine an average velocity and hence a gradient.

Channel uses the latter method, as it is easier to carry out a manual check of

the results. However, there is usually very little difference between the results

given by the two methods.

Preparing the data The first part of the open channel to be modelled has two reaches, defined by

the three sections shown opposite:



Example 9 Page 9.3

Section 1

Section 2

Section 3



Page 9.4 Example 9

These sections must be input to the program using x and y co-ordinates. The y

co-ordinates are the levels at each point. The x co-ordinates define the width

of the channel and only need to be given relative to one another.

Defining the sections Look at the hard copies of the results at the end of this example (pages 9.23

to 9.26), coordinates are defined in x and y format for each section.

Flows and roughnessThe roughness variables defined in section 1 apply to the reach from sections

1 to 2. Similarly, the roughness variables defined in section 2 are used

between sections 2 to 3 and so on.

Remember that backwater analysis starts from the outfall, so that section 1 is

downstream of section 2.

The full cross section details for each station are given in the results. This

example has been deliberately chosen for its awkwardness to demonstrate

how complex sections can be modelled.

Opening ChannelAfter the Channel title screen, you will see the Channel Open screen:

The Start a New Job button is already highlighted, so click OK or pressReturn.



Example 9 Page 9.5

Channel DetailsChannel presents you with Channel Details spreadsheet. The row for Section

1 under Chainage is already highlighted for you to enter the value. For this

example, enter zero (or leave the field blank) and press Return. The cursormoves to the Type field, leave this as Open and press Return again to move

to the Flow field, we will come back to different section types later in the

example.

We must enter a flow for the first section and at points where the flow

changes otherwise it will default to the previous value by pressing Return.

Enter 8 m3/s and press Return. Losses may also be varied for each section,

but in this example you need simply to press Return again to reach the Level

column. We must enter a value for the first section, enter 10m. We cannot

edit the level for any other section as the program calculates the level.



Page 9.6 Example 9

Channel CoordinatesPressing Return in the Level column will have moved the cursor to the first

row of the Channel Coordinates spreadsheet:

Enter the data shown here. Note that the cursor automatically moves betweenthe x and y coordinates and n value. The n value must be entered for the first

cell and at points where it changes otherwise it will default to the previous

value by pressing Return.

When the cursor moves to the eleventh row, press Return again and it

automatically takes you to Section 2.



Example 9 Page 9.7

Section 2

For Section 2 the chainage is 80, the flows is as for section 1 so will be

automatically filled in if you press Return and there are no losses to enter.

The x/y co-ordinates and n values are as shown.

When you have finished entering these co-ordinates, note that Channel

produces its first results:



Page 9.8 Example 9

Finally, enter the data for Section 3. The chainage is 187.

Longsection The Longsection and Cross Section are displayed alongside the Channel

Details. To view full screen longitudinal sections of the system, simply click

on the Longsection icon in the toolbar:

Longsection

You can move between sections using the scroll box at the bottom of the

screen; if you click on the scroll box, you can then use the keyboard arrows.

You can also adjust the number of sections displayed using the arrows at the

top of the screen.

Cross sectionsTo view full screen cross sections of each section, click the Cross Sectionicon in the toolbar.

Cross Section

Again, clicking in the scroll bar enables you to switch between sections,

using the keyboard arrows if you prefer.



Example 9 Page 9.9

Cascaded viewsAs with all Micro Drainage modules, Channel allows you to view all open

windows simultaneously. Simply select Cascade from the Window menu.

You can move quickly between the spreadsheet and the graphic views of the

sections simply by clicking on the window you require.

PrintingYou can now print out your results. Simply click on the Print icon in the

toolbar.

Print

When you select Print, Channel shows you the Print dialogue box:

These options are self-explanatory; you choose the options you would like to print simply by clicking in the appropriate box. Click the Update Preview

button to see a print preview. When you are satisfied with the selected

options click the Print icon at the top of the dialogue to send the job to the

printer.



Page 9.10 Example 9

Super-critical flow The usual flow in a river is sub-critical or tranquil. A stone dropped in the

river will cause ripples upstream - the flow is slower than the wave speed.

Super-critical (or rapid) flow has a parallel in supersonic speed. Ripples froma stone, or a stick placed in the water, will cause waves downstream, but the

velocity is too fast for the wave to travel upstream.

The principles of backwater analysis do not apply if the flow is super-critical,

as downstream effects do not backwater upstream. Accordingly, if the

channel bed is steep and rapid flow results, Channel shows the result in red.

This illustrates that backwater analysis has not been possible and the depth

calculated for that section is based on a stage discharge relationship.

The hard copy places an asterisk beside the result to show it has not been

calculated by backwater. In addition, the results are shown on one line as

they are based on that section and not on the average values of two sections

as in normal backwater.

To view this effect, and to practice the entry of circular sections, we will

enter three additional sections as shown opposite.



Example 9 Page 9.11

Section 4

Section 5

Section 6



Page 9.12 Example 9

Introducing super-crit ical flowOn the Channel Details spreadsheet move the cursor to Section 4 of the

Chainage Details. Enter a chainage of 200, a flow of 6.000 with the data

shown here for the x/y coordinates and Manning’s n.

Section 4, at 200m, provides for super-critical flow, as it is much higher than

the previous section. Note that super-critical flow is shown in red on the

results section of the spreadsheet.



Example 9 Page 9.13

Pipe sectionsWe shall now add two circular sections. Move the cursor to Section 5 on the

Chainage Details spreadsheet. Enter 230m for the Chainage and then change

the Type to Pipe.

The coordinates form changes to show the appropriate entry form. Click in

the Flow column, then click Return until the cursor appears in the IL column.

Now enter the data shown here for Section 5.

Copying sectionsSection 6 has the same diameter and invert level as Section 5 so we can copy

these details by clicking the Insert Section button in the toolbar.

Insert Section

The Insert Section No form appears from which you should select the last

option leaving the change in invert level as 0m, then click OK .



Page 9.14 Example 9

Change the Chainage to 250m and check the other details have been copiedcorrectly as below.

Note: The results for Section 6 show a return to tranquil flow. Channel

does not model hydraulic jumps, so the water depths for the super-critical

sections must be regarded as estimates for use as data with which to

backwater the next sub-critical section. If a detailed analysis of super-critical flows and hydraulic jumps is required, then these must be

undertaken manually and the appropriate specification applied to stilling

basins etc.



Example 9 Page 9.15

Introducing an intermediate sectionThe cross-sections in backwater analysis should not change rapidly. Apart

from super-critical flow, another reason the result may appear in red is that

the sections are too dissimilar.

If we introduce an intermediate section between 187m and 200m the

backwater may be successful. To do this, move the cursor back onto Section

3 and click on the Insert Section icon again. Choose Insert Intermediate After

Section No and click OK to accept the insert section position.

Channel inserts a new line below the highlighted Section. The old Section 4

now becomes Section 5. Overtype the Flow value with 6 m3/s for the

intermediate section and update the n values for the Channel Coordinates as

below:

Intermediate sections should always be tried if the results appear in red.

However, if the flow is super-critical then intermediate sections will not alter

the result from red to blue.



Page 9.16 Example 9

Local lossesWith the introduction of the intermediate section we still have super-critical

flow at Section 6.

This is because the water levels have dipped due to the large changes in

velocities, even though there is an increase in the energy line upstream. A dip

in water levels may be observed in streamlined sections, but in most

circumstances local losses will occur.

In this example we have a tributary entering the channel between Sections 4

and 3 (194m and 187m), with a flow of 2m3/s. To account for the additional

local losses caused, enter a factor of 1.0 at Section 3. To enter the local loss

factor, simply click in the K field for Section 3 and enter the appropriate

value - in this case, 1.0.

Also the flow exits a culvert into an open channel between Sections 6 and 5

(230m to 200m). If we apply a local loss factor of 1.5 at Section 5, the effect

is duly registered and the results show a more realistic conclusion. The

results now show a much better balance of levels and velocities and, indeed,

a properly accurate reflection of reality:

Note: The super-critical flow at Section 6 has been removed.

Now save the file as Example 9.bckx.



Example 9 Page 9.17

The value of kTo demonstrate the calculations required to determine an appropriate value

for k - the local loss factor - within Channel we will show how it may be

applied to another reach of the channel.

Let us assume that a short culvert restricts the flow in the main channel

between Sections 1 and 2. As the culvert is short (say less than 10m) the

friction loss is negligible and it is not necessary to input section details at

each end of the culvert. A local loss factor input at Section 1 (to be used in

the reach 1 to 2) may be sufficient to account for this obstruction.

The entrance and exit to and from the culvert are abrupt. At the entrance,

50% of the kinetic energy increase from the channel to the culvert is lost,while at the exit 100% of the kinetic energy decrease from the culvert to the

channel is also lost. This may be expressed as follows:

v1 = average channel velocityv2 = velocity in culvert

entrance loss = 0.5 * (v22 - v12)/ (2 * 9.81)exit loss = 1 * (v22 - v12)/ (2 * 9.81)

Total loss = 1.5 * (v22 - v12)/ (2 * 9.81)

The k value in the program is the proportion of the kinetic energy of the

average channel flow lost due to the obstruction. Therefore the k value to be

used in the program is:

k * v12 / (2 * 9.81) = 1.5 * (v22 - v12)/ (2 * 9.81)

If v1 = 1 m/s and v2 = 1.2 m/s, then k = 0.66

This calculation is not applicable if the velocity in the culvert is critical. The

culvert then becomes the control. The critical depth for the culvert must be

calculated and a new backwater curve calculated upstream of the critical

section.

If the culvert were long it would be necessary to specify a section at each end

of the culvert, as friction losses would be significant. Say the culvert starts at



Page 9.18 Example 9

Section 2 and ends at Section 3 and is 150m long. As the x co-ordinates for a

cross section must be at least .001m apart, the vertical sides of a culvert can

only be specified as near vertical (i.e., with a 1 mm slope).

At Section 2 the exit loss from the culvert must be specified as:

k * v22 / (2 * 9.81) = 1 * (v22 - v12)/ (2 * 9.81)

Note that the average velocity for the reach under consideration (between

Sections 2 and 3) is v2 - the velocity in the culvert and k at Section 2 is

deemed to be a proportion of the kinetic energy based on this velocity. v1 is

the average velocity in the channel between Sections 1 and 2.

The entrance loss is now specified at Section 3 and the k factor is calculated

as follows:

k * v12 / (2 * 9.81) = .5 * (v22 - v12)/ (2 * 9.81)

k is now a proportion of v1 which is the average velocity in the channel

between Sections 3 and 4.

So the local loss factor must always be expressed as a proportion of the

average velocity in the reach being considered. If k is specified at Section n it

will be applied to the reach from Section n to Section n+1 and it must be

based on the average velocity in this reach.

It is not possible in this example to give definitive advice on what proportion

of the kinetic energy is lost at each obstruction, as it will always depend on

the geometry of the structure. It is a good starting point to assume that it is a

proportion of the change in the kinetic energy of the flow, as this exampleillustrates. However site measurements are very useful in determining local

loss factors.

The ratio of the cross sectional areas of the channel and the obstruction may

change during high flows. An allowance must be made for this if water levels

taken at low flows are used to calculate local loss factors.



Example 9 Page 9.19

Analysing in Simulation A.P.T. Channel is useful for backwater analysis of river sections with known flows

but if you have additional areas draining to the river sections or you want to

more accurately model super-critical flows the Simulation module can read inChannel files for analysis.

Start the Simulation A.P.T. module and select Open Existing File at the Open

screen. Change the file type from .mdx, to .bckx using the drop down menu

and open the file Example 9.bckx.

At the Simulation Criteria screen enter the values as shown below:

Click OK to the Simulation Criteria.



Page 9.20 Example 9

Editing the Network DetailsSelect Network Details from the Network menu. Starting at the most

upstream section, section 7 in the Channel file, the file has been converted to

a network with pipe numbers. The top spreadsheet shows the Pipe DIA for

the open sections from Channel as negative numbers indicating they are from

a conduit library (see Example 2 for details of using your own conduit

library). The conduit library has been created and will be saved as part of the

.mdx file. The circular sections have been loaded as pipes.

Enter the flows from Channel into the Base Flow column; note that these

values are in l/s, rather than m3/s. Enter 6000 l/s for pipe 1.000 and 2000 l/s

at pipe 1.004 where the additional flow enters the network. We will also

enter an extra 5ha at pipe 1.004.

The spreadsheet also shows manholes have not been designed between the

open sections. If the manhole dimensions cannot be seen, open the toolbar

Preferences and turn on the US/MH Diam/Len and US/MH Width columns.A manhole has been assigned between the open section and the pipe. In

reality this will not exist, to avoid taking into account additional storage

change select the Preferences button and add the US Connection column.

Close the preferences form and change the manhole type to Junction.

The yellow background indicates values have been altered from the original

file.



Example 9 Page 9.21

The local loss factor, K , from Channel can be entered in the Manhole

Headloss form available from the Network menu. Enter the details as shown

below to represent the local losses. The values turn from blue to red to

indicate they are user defined.

Open the Network Manager from the Site menu, Analyse will be set to off,

shown as red. Click on the GO icon and it will change to green, now you can

run the analysis as usual, view the Summary of Results and display the

graphical views. For more information on the Simulation module see

Example 7 of this manual.



Page 9.22 Example 9

Editing in System 1 A.P.T. or DrawNetChannel files may be imported to System 1 with A.P.T. or DrawNet as

Existing Networks. To import into an existing file, select Network Manager

from the Site menu and click the Import icon on the toolbar, change the filetype to .bckx and select the required file.

To import the network into a new file select Open Existing File at the Open

screen and follow the procedure as for Simulation. For more information on

the DrawNet module see Example 13 of this manual.





West St r eet Channel

Newbur y RG14 1BD The backwat er st ep met hod


Fi l e Exampl e9. bckx Checked by

XP Sol ut i ons Channel 2014. 1

NOTE: - Sl ope i s t he gr adi ent of t he ener gy l i ne not t he wat er l i ne.

The wat er l evel i s t he energy l evel - V² / 19. 62


CHAIN

(m)

K N FLOW

(m³/s)

AREA

(m²)

VEL

(m/s)

PERIM

(m)

A/P

(m)

SLOPE

(1:X)

LEVEL

(m)

0 8. 000 22. 66 21. 30 10. 000

0. 000 0. 035 8. 000 19. 19 0. 42 17. 80 1. 08 5074

80 8. 000 15. 72 14. 29 10. 009

0. 000 0. 035 8. 000 16. 23 0. 49 19. 48 0. 83 2658

187 8. 000 16. 74 24. 67 10. 051

1. 000 0. 323 7. 000 13. 40 0. 52 20. 04 0. 67 20

194 6. 000 10. 07 15. 42 10. 397

0. 000 0. 393 6. 000 8. 09 0. 74 11. 65 0. 69 7

200 6. 000 6. 12 7. 89 11. 194

1. 500 0. 030 6. 000 4. 61 1. 30 6. 24 0. 74 152230 6. 000 3. 10 4. 59 11. 250

0. 000 0. 012 6. 000 3. 15 1. 90 4. 63 0. 68 1171

250 6. 000 3. 21 4. 66 11. 280










COORDI NATES


Sect i on No 1 Chai nage ( m) 0

Open Channel Coordi nates

X (m) Y (m) n X (m) Y (m) n X (m) Y (m) n X (m) Y (m) n X (m) Y (m) n

1. 000 12. 000 1. 000 12. 000 10. 000 0. 035 23. 150 8. 230 0. 035 38. 000 10. 300 1. 000 42. 000 11. 200 1. 000

5. 000 10. 500 1. 000 19. 200 8. 110 0. 035 34. 000 10. 200 1. 000 40. 000 11. 000 1. 000 44. 000 12. 000 1. 000



X (m) Y (m) n X (m) Y (m) n X (m) Y (m) n X (m) Y (m) n X (m) Y (m) n

1. 000 12. 000 1. 000 8. 000 10. 000 0. 035 17. 340 8. 400 0. 035 35. 000 10. 700 1. 000 41. 000 11. 700 1. 000

5. 000 10. 300 1. 000 13. 000 8. 120 0. 035 23. 100 10. 600 1. 000 37. 000 11. 500 1. 000 43. 000 12. 200 1. 000



X (m) Y (m) n X (m) Y (m) n X (m) Y (m) n

0. 000 12. 000 0. 035 8. 600 8. 200 0. 035 26. 000 9. 800 1. 000

5. 000 8. 500 0. 035 12. 000 9. 600 1. 000 29. 000 11. 000 1. 000



X (m) Y (m) n X (m) Y (m) n X (m) Y (m) n

0. 000 12. 500 0. 035 6. 800 9. 135 0. 035 17. 350 9. 940 1. 000

5. 000 9. 285 0. 035 10. 350 9. 840 1. 000 20. 750 11. 850 1. 000



X (m) Y (m) n X (m) Y (m) n X (m) Y (m) n X (m) Y (m) n

0. 000 13. 000 0. 030 5. 000 10. 070 0. 030 8. 700 10. 080 0. 030 12. 500 12. 700 0. 030


Ci rcul ar Secti on Det ai l s

Di ameter (m) 4. 00 I nvert Level (m) 10. 070 n 0. 012


Ci rcul ar Secti on Det ai l s

Di ameter (m) 4. 00 I nvert Level (m) 10. 070 n 0. 012











0

8. 000

0. 42

5074

1 2 .

0 0 0

1 2 .

0 0 0

8 .

1 1 0

1 0 .

0 0 0

80

80

8. 000

0. 49

2658

1 2 .

2 0 0

1 2 .

0 0 0

8 .

1 2 0

1 0 .

0 0 9

107

187

8. 000

0. 52

20

1 1 .

0 0 0

1 2 .

0 0 0

8 .

2 0 0

1 0 .

0 5 1

7

194

6. 000

0. 74

7

1 1 .

8 5 0

1 2 .

5 0 0

9 .

1 3 5

1 0 .

3 9 7

6

200

6. 000

1. 30

152

1 2 .

7 0 0

1 3 .

0 0 0

1 0 .

0 7 0

1 1 .

1 9 4

30

230

1 4 .

0 7 0

1 4 .

0 7 0

1 0 .

0 7 0

1 1 .

2 5 0

230

6. 000

1. 90

1171

1 4 .

0 7 0

1 4 .

0 7 0

1 0 .

0 7

0

1 1 .

2 5

0

20

250

1 4 .

0 7 0

1 4 .

0 7 0

1 0 .

0 7

0

1 1 .

2 8

0

Chai nage ( m)

Fl ow ( m³ / s)

Vel oci t y ( m/ s)

Sl ope ( 1: X)

L/ Bank Level ( m)

R/ Bank Level ( m)

Wat er Level ( m)

I nver t Level ( m)

Lengt h ( m)

Chai nage ( m)

Fl ow ( m³ / s)

Vel oci t y ( m/ s)

Sl ope ( 1: X)

L/ Bank Level ( m)

R/ Bank Level ( m)

Wat er Level ( m) I nver t Level ( m)

Lengt h ( m)

Datum ( m) 5. 000

Ver Scal e 200

Hor Scal e 1900

Datum ( m) 6. 000

Ver Scal e 200

Hor Scal e 1900











0 .

0 0

0

1 2 .

0 0 0

5 .

0 0

0

8 .

5 0 0

8 .

6 0

0

8 .

2 0 0

1 2 .

0 0

0

9 .

6 0 0

2 6 .

0 0

0

9 .

8 0 0

2 9 .

0 0

0

1 1 .

0 0 0

0 .

0 0 0

1 2 .

5 0 0

5 .

0 0 0

9 .

2 8 5

6 .

8 0 0

9 .

1 3 5

1 0 .

3 5 0

9 .

8 4 0

1 7 .

3 5 0

9 .

9 4 0

2 0 .

7 5 0

1 1 .

8 5 0

X- Coord ( m)

Y- Coord ( m)

Sect i on Number 3

Chai nage ( m) 187

Wat er Level ( m) 10. 051

X- Coord ( m)

Y- Coord ( m)

Sect i on Number 4 Chai nage ( m) 194

Wat er Level ( m) 10. 397

Datum ( m) 5. 000

Ver Scal e 150

Hor Scal e 500

Datum ( m) 6. 000

Ver Scal e 150

Hor Scal e 500



Example 10 Page 10.1


Example 10 - Source ControlInfi ltration Systems



Page 10.2 Example 10

IntroductionThe use of infiltration techniques has risen to the top of the engineering

agenda. The pressure to improve the environmental impact of the drainage

network led first to a focus on the improvement and, where possible, removalof combined sewer overflows (CSOs).

Increasingly, however, the emphasis is shifting towards prevention rather

than cure and, ultimately, to solutions that deal with the entire network, from

inflow to outflow. This approach has been dubbed 'Joined-up Thinking'.

Infiltration has a major role to play in this strategy. Source Control is the first

program of its kind to provide a complete analysis and design solution for

engineers, which can integrate infiltration techniques with conventional

design solutions.

Opening Source ControlOpen the Source Control module.

Alternatively, use your preferred Windows method. You are presented with

the Source Control Open screen.

This example is based on a 30 hectare site. Approximately 33% of the surface

area is impermeable, with six hectares paved and four hectares roofed. We

have an allowable discharge of 20 l/s.




Within the Source Control Open screen, double click on the Design Guide

icon.

The Design Guide is a tool designed to simplify the complex process of

designing a solution incorporating the use of infiltration techniques. Begin by

clicking the Quick Storage Estimate button.

The Quick Storage Estimate window appears.

Note: Ciria 156 (table 4.6) lists safety factors of between 1.5 and 10.

These refer to a Cv of 1. Increase the safety by a factor of 1.33 to allow

for the Wallingford runoff model.




This process will give us a rough idea of the storage required and show

whether or not infiltration is appropriate as part of the solution.

Enter the variables as shown. To find the Infiltration Coefficient, click the

Calculator button.

The formula is based on the site test from Ciria 156 (Ciria 697) and BRE 365.

Enter the data as shown and click OK . The value 0.2m/hr is enteredautomatically.

Click Analyse and the routing calculations are carried out.




We can already see that the use of infiltration is likely to make a substantial

difference to the required storage capacity. Click on the Design tab to see a

graphic representation of the result.

For this example we will route the roofed areas into soakaways and half the

paved area into a porous car park.




The outflows from the soakaways and the car park will be combined with the

remaining paved area run-off, which will feed into a storage pond.

Since the pond is limited by our maximum discharge of 20 l/s, we will design

the soakaways and the car park to maximum discharges of 10 l/s. This is because the combined discharge from upstream must not exceed the final

discharge rate, otherwise the drain down period may cause the pond to fail.

Note: This is not the only design option. We could, for example, specify

the soakaways with no discharge (infiltration only) and then have 20 litres

per second available for the car park. For a real project, your best

judgement should be applied according to the specific circumstances.

Quick DesignSource Control's Quick Design facility enables us to enter the necessary data

for the design of each solution quickly and easily.

Click OK to close the Quick Storage Estimate window and click the Quick

Design button on the Design Guide and enter the variables for the soakaways

as shown. Most of the values will have been filled in automatically, however

you must alter Area and Discharge.




Click Analyse and the routing calculations for the soakaways are carried out.

The results show that we require between 658 and 782 soakaways of 0.9m

diameter with a 1.35m pit size (1 metre effective depth). To see a section

through the soakaway design, select the Structures tab.




Detailed DesignWe can now begin to design the soakaway solution in detail. Click OK to

close the Quick Design function and choose Detailed Design in the Design

Guide.

Enter the Global Variables as shown and click OK .

For the Rainfall and Network Details you have only to check the data are as

shown.




Source Control takes the rainfall information from Quick Design

automatically.

Click OK again and the Time Area Diagram spreadsheet opens. Enter the

data as shown and click OK .

At the Lined Soakaway Structure window, enter the data as shown.

Note that we have used an estimate of 720 soakaways, based on the results

from Quick Design. Click OK to continue.




Hydro-Brake®

Source Control will calculate the Hydro-Brake® automatically. To do this

change the Hydro-Brake® Range to “Hydro-Brake

® (foul, combined, SW)”

and click the Calculator button.

Calculator

At the Hydro-Brake® Calculator enter the data for the Design Head and

Design Flow as below. Choose the Md6 SW Only and click OK .

The Hydro-Brake® flow characteristics are calculated for you.

Enter an Invert level of 100m and click OK .




Go with the Flow CheckWe are now ready to perform the calculations for the soakaways. Click Go to

run the analysis and the calculations are carried out.

Run Analysis.

ResultsWhen the calculations are complete, save the data as Soakaways.srcx.

The summary shows a maximum depth of 0.988m is reached during the 60

minute winter storm. This is within our available soakaway depth of 1 metre.

This result is satisfactory, but if you needed to edit the size of the soakaways

you can do this via the Edit menu.




Car park

We now move on to design the porous car park, following a similar process

to the one used for the soakaways. Again, select Quick Design from the

Design Guide toolbar and enter the data as shown.

Click Analyse and the results are as follows:

For a car park of 0.4m depth, we require a surface area of between 3694.0m

2

and 4054.4m

2.




Again, you can view a section by clicking the Structures tab.

Click OK and then click on Detailed Design from the Design Guide which

will start a new job.

This time select Porous Car Park as the storage structure and Orifice for the

outflow control. Enter the rainfall data as before.




For the Time Area Diagram, enter the figures shown to give the total

contributing area of three hectares.

System Details

We will try a square car park with 63m sides, as this gives a surface area of

3969m2 within the range from the Quick Design results.

Enter the figures as shown.




Membrane Percolation is the rate at which water can flow through the geo-

textile used in the surface of the car park. This, combined with the surface

area of the car park, enables Source Control to calculate a maximum

percolation (inflow) value, shown for reference at the top of the box (4961.3

l/s). Click OK to continue.

Source Control will size the orifice automatically.

Click the Calculator button and enter the required flow details.

Click OK and the value is automatically entered into the analysis.

In this instance we are given an orifice diameter of 89mm. This is too smalland will block easily. Accordingly, we will use a Hydro-Brake

® instead.




Hydro-Brake®

Select Global Variables from the Edit menu and alter the Outflow Control to

Hydro-Brake® and click OK .

You are presented with the Hydro-Brake® Outflow Control dialogue box.

Change the Hydro-Brake® range and enter the data for invert level, design

head and design flow and the remaining values are calculated automatically.

From the pull down menu select Md8 for the Hydro-Brake

®

type. Click OK and then click the GO button to Analyse.




ResultsSave your file as CarPark.srcx.

The results show a maximum depth of 0.394 metres for the 60 minute winter

storm. This is within our designated maximum of 400mm for the car park.

Again, in a real project you may well wish to refine the design, but for the

purposes of this example the results are acceptable. Note also that the Hydro-Brake® we specified has not exceeded the maximum discharge rate of 10 l/s.

Note: Don’t worry if your results don’t show a status of OK. Flood Risk is

given if the water level is within a specified margin of the cover. This can

be found by selecting Preferences from the File menu. Although it is

always advisable to design using such a safety factor, it is not necessary to

use a value of 300mm (the default) in this case. Since we are designing to

a total depth of 400mm, 200mm is a more practical value to represent the

space needed for the car park construction.




The PondThe last element of our tripartite approach to storage is the pond itself. In this

instance, the storage required is dependent upon the outflows from the car

park and the soakaways. For this reason we cannot use Quick Design to giveus a starting point. Accordingly, we must go straight to the Detailed Design

tool.

Select the options shown for Global Variables and click OK . The data for the

Rainfall Details and Time Area Diagram are the same as for the car park.

AreaWe can calculate the area for the pond using the Quick Storage Estimate

result. This indicated that storage of between 951 m3 and 3009 m

3 would be

required if an infiltration system were to be used.

In this case, only two thirds of the storage utilises infiltration, so we can be

sure that the final result will be towards the upper bound given by the

estimate. For this exercise we will assume a figure of 2000 m3.

With just over half of this amount being given by the soakaways and the

carpark we have approximately 900m3 remaining for the pond. If the water

level is not to exceed a depth of 1 metre, the pond area is as shown.




Note: As the Plan Area is constant we only need to enter the first value.

This area will automatically be repeated by the software.

Click OK and enter the data for the Crown Vortex Valve® Outflow Control.

You can use the calculator as shown for the Hydro-brake® earlier.




Enter the parameters as shown for the overflow weir, which is 1 metre above

the invert of the structure.

Click GO. When the analysis has finished save the file as Pond.srcx. The

results are as shown.




CascadeAt this stage the results are not significant because they do not include the

flow from the car park and the soakaways. To do this, click the Cascade

button on the design tool.

To load the three structures into the Cascade screen, click the Add button.

Add

Double click on each item in turn which will place the icons in the design

area. The icons will be stacked on top of one another. To lay them out as

shown, click on each one in turn with the left mouse button and drag it to the

appropriate place.

To connect the structures, click on the green outflow arrow of the soakaway

with the right mouse button. Holding the button down, drag the green line

that appears to the inflow arrow on the pond icon and release the mouse

button. Repeat this for the car park.

With both links defined, click GO to run the Cascade analysis and save the

file when prompted as Example10.casx.




We now have a detailed analysis for the whole storage system. You can

switch between the results for each structure using the Pond Selector . Select

the Pond structure.

From the results we can see that the Pond overflow has been activated so we

need to go back and enlarge the size of the structure.

Re-designing the PondTo re-load the original pond design file simply click the Edit button on the

Pond Selector when Pond is selected. This reopens the file at the storage

structure form for editing.

Increase the size of the pond to 1080m2 by clicking the Scale Factor arrow up

until it says 20 or typing 20 in the box.




Click the Scale button and it will automatically scale each number in the

table by 20%. Click OK , run the analysis and save the file.

We must now re-run the Cascade analysis. Click on the Cascade button and

the Cascade Sequence form still contains the original data. Click GO to run

the analysis again and then save when prompted.

The results show that enlarging the Pond by 20% stops the overflow from

activating. Here, however, the Pond uses a total of 1040.9m3 of storage.

With the soakaways and the car park we now have a total of 2178.3m3, in the

middle of the range originally given by the Quick Storage Estimate.




Graphics and animationSource Control incorporates a variety of graphical representations of the

designs. They are available for each component of the system and may be

used in conjunction with each set of results as they are presented.

However, for the purposes of this example we shall look at them here in

order to demonstrate the versatility of the Pond Selector.

Select the Graphs option by clicking the Graphs icon.

Graphs

The graphs for the structure selected in the Pond Selector appear. Again, you

can switch between the structures using the Pond Selector .

The available graphs can be selected from the toolbar, click Show Total

Flow/Component to ensure all flows are displayed.




For an animated representation of the control, click the Animation icon.

Animation

The animation for the soakaway is shown below.

As with all Micro Drainage animations, the Video Controls form appears

with controls similar to those on a media player, play, pause, advance and so

on. The trace icon on the left of the toolbar is selected, giving a visual

representation of the process of the storm. You can use the Storm Selector toswitch storm durations and the Pond Selector to choose another structure.

Source Control also enables you to view an animation of the complete

system. To do this, select Animation from the Cascade menu.




The structures work in the same way and you can see the whole system in

operation, with the relationships between the structures clearly shown.

The animation may also be viewed in 3D by selecting 3D Animation fromthe Cascade menu.




Note: You may not wish to use soakaways of the same design for the

whole project. Some areas of the site may cater for larger effective depths

while other areas may allow the placement of house soakaways.

The same may apply to the car park. In this example we have used a singledesign of soakaway and car park to keep things simple.

If you do choose to use multiple designs, you will probably find it easiest

to design several batches of each structure before proceeding to link them

together in the Cascade stage.

CASDeFUsers with CASDeF can achieve a similar answer in a fraction of the time.

To demonstrate this open Soakaway.srcx by clicking Edit on the Pond

Selector when Soakaways is selected and downsize the number of soakaways

used to 1.

Select CASDeF Controller from the Edit menu and set the Maximum

Allowable Water Level to 101m. This means CASDeF will size the number

of soakaways to keep the depth of water below 1 m.

Select the Analyse menu or click the drop down arrow next to the GO icon

and choose CASDeF Analysis.

The Summary of Results show a Maximum Water Level of 100.998 with 9.8

l/s discharge. View the Soakaway details and you will see CASDeF has

achieved this with 714 soakaways.




Follow the same procedure with the carpark. Downsize the carpark width to

1m and set the Maximum Allowable Water Level to 100.4. CASDeF sets the

width to 62.8m, which produces an acceptable result.

As before we cannot design the pond in this way, as the inflow from the other

two structures is required. Open the pond file and set to pond area to 1m2. Setthe Maximum Allowable Water Level to 100 (the overflow level). Run the

analysis as normal. Don’t worry if the pond fails at this point.

Re-open the original Cascade file and accept the warning. Instead of clicking

GO click the CASDeF icon.

CASDeF

CASDeF runs the Cascade analysis but upsizes each of the structures as

required.

The Summary shows all our requirements have been met. In fact CASDeF

has produced a solution that uses smaller structures than our original design.




Joined up Thinking

Having designed our three structures and shown they will work together the

last stage of the design process is to test them 'in situ'. We can download the

structures into Simulation to test the effects of the connecting pipe network.

SimulationThe network we will be using is supplied with the software. It will have been

installed to your machine during the Setup process. Start Network using your

preferred method. At the Open screen select Open Existing File and load the

file Example10.mdx from your \Micro Drainage 2014\Data directory.

The outflow controls have already been defined. These can be seen byselecting Online Controls from the Network menu.

The only thing left for us to do is to incorporate the three storage structures.

Note: When we download structures from Source Control, Simulation will

only incorporate the appropriate volume and infiltration rates. Any outflow

or overflow controls must be re-defined by the user in Simulation.




Drag & DropWe are now ready to drop the pond and infiltration systems into the network.

Open the Plan (available from the Graphics menu) and from the toolbar click

on the Toolbox icon and click on the Structures tab.

Toolbox

Drag the Lined Soakaway icon and drop it on the upstream of pipe 1.001.

The DS Pipe Number and Control type have been filled in for you. Click the

Import button and choose Soakaway.srcx. The file is loaded and the rest of

the details filled in for you. Click OK to return to the Plan.

Now use the same procedure to add Carpark.srcx to the upstream manhole of2.001 and the Pond.srcx to the upstream manhole of 1.004.

Note: More details can be found on the use of Simulation and drag-drop

controls in Example 7.




The Full PictureClick GO to run the Analysis.

When the results are displayed, click on the Summary Preferences icon and

turn on the Infiltration Flow column.

Simulation has performed a full hydrograph analysis including backwater

effects and we can see our design still operates as expected. These results are

for the 360 minute Winter storm (the critical duration in Cascade) but in a

real job it would be necessary to run a full range of storms. (See Example 8).

Note: If you have not used CASDeF in Source Control the results obtained

from Simulation will be slightly different to what is shown above.

ConclusionSource Control has enabled us to design a complex and sophisticated system

in a few easy steps, with checks and error controls at each stage:

• Quick Storage Estimate gives a useful indication of the likely storage

requirement and also serves as a feasibility study on the effect of using

infiltration.

•

The Quick Design tool gives rough sizes for each infiltration structureand these enable you to complete detailed designs for the infiltration

structures quickly and easily.

•

The final storage structure is then completed, using the Quick Storage

Estimate result to help calculate the likely required size.

•

The Cascade tool uses a graphical user interface to design the finished

control structure. Source Control then calculates final results for the

complete inter-connected system.

• Each of the storage structures can be downloaded into Simulation to

give a complete design including all of the interconnecting pipe work.






Newbury RG14 1BD Infiltration Systems


File Soakaways.srcx Checked by




Half Drain Time : 47 minutes.

Storm

Event

Max

Level

(m)

Max

Depth

(m)

Max

Infiltration

(l/s)

Max

Control

(l/s)

Max

Σ Outflow

(l/s)

Max

Volume

(m³)

Status

15 min Summer 100.676 0.676 109.4 9.4 118.1 482.8 O K

30 min Summer 100.812 0.812 124.1 9.4 133.2 580.0 O K

60 min Summer 100.871 0.871 130.5 9.4 139.8 621.9 O K

120 min Summer 100.858 0.858 129.1 9.4 138.4 613.0 O K

180 min Summer 100.808 0.808 123.7 9.4 132.8 576.9 O K

240 min Summer 100.753 0.753 117.7 9.4 126.7 537.8 O K

360 min Summer 100.657 0.657 107.4 9.4 116.1 469.0 O K

480 min Summer 100.577 0.577 98.7 9.4 107.3 412.0 O K

600 min Summer 100.509 0.509 91.4 9.4 100.1 363.8 O K

720 min Summer 100.452 0.452 85.2 9.4 94.1 322.5 O K

960 min Summer 100.359 0.359 75.2 9.4 84.4 256.3 O K

1440 min Summer 100.235 0.235 61.8 9.2 71.0 167.8 O K

2160 min Summer 100.135 0.135 51.1 6.2 57.3 96.6 O K

2880 min Summer 100.080 0.080 45.1 3.1 48.2 57.2 O K

4320 min Summer 100.043 0.043 36.2 1.2 37.4 30.8 O K

5760 min Summer 100.035 0.035 29.1 0.8 29.9 24.7 O K

7200 min Summer 100.029 0.029 24.5 0.6 25.1 20.7 O K

8640 min Summer 100.025 0.025 21.1 0.5 21.6 17.9 O K

10080 min Summer 100.022 0.022 18.6 0.4 19.0 15.7 O K

15 min Winter 100.763 0.763 118.9 9.4 127.8 545.0 O K

30 min Winter 100.922 0.922 136.0 9.6 145.6 658.3 O K

60 min Winter 100.988 0.988 143.1 9.8 153.0 705.6 O K

120 min Winter 100.957 0.957 139.8 9.7 149.5 683.4 O K


Storm

Event

Rain

(mm/hr)

Flooded

Volume

(m³)

Discharge

Volume

(m³)

Time-Peak

(mins)

15 min Summer 76.035 0.0 569.9 19

30 min Summer 49.499 0.0 742.1 31

60 min Summer 30.811 0.0 924.0 50

120 min Summer 18.615 0.0 1116.5 84

180 min Summer 13.715 0.0 1234.0 118

240 min Summer 10.995 0.0 1319.0 152

360 min Summer 8.034 0.0 1445.8 218

480 min Summer 6.428 0.0 1542.4 282

600 min Summer 5.404 0.0 1620.7 344

720 min Summer 4.687 0.0 1687.1 406

960 min Summer 3.743 0.0 1796.4 530

1440 min Summer 2.723 0.0 1960.3 768

2160 min Summer 1.979 0.0 2136.7 1128

2880 min Summer 1.577 0.0 2270.0 1476

4320 min Summer 1.143 0.0 2469.6 2192

5760 min Summer 0.910 0.0 2620.2 2888

7200 min Summer 0.762 0.0 2742.5 3576

8640 min Summer 0.659 0.0 2845.7 4304

10080 min Summer 0.583 0.0 2935.7 5136

15 min Winter 76.035 0.0 638.4 19


120 min Winter 18.615 0.0 1250.5 90

180 min Winter 13.715 0.0 1382.2 126

240 min Winter 10.995 0.0 1477.3 162












Storm Event

MaxLevel

(m)

MaxDepth

(m)

MaxInfiltration

(l/s)

MaxControl

(l/s)

MaxΣ Outflow

(l/s)

Max Volume

(m³)

Status

360 min Winter 100.662 0.662 107.9 9.4 116.6 472.7 O K

480 min Winter 100.553 0.553 96.1 9.4 104.8 395.0 O K

600 min Winter 100.464 0.464 86.6 9.4 95.4 331.6 O K

720 min Winter 100.391 0.391 78.7 9.4 87.8 279.3 O K

960 min Winter 100.280 0.280 66.7 9.4 76.1 200.2 O K

1440 min Winter 100.154 0.154 53.1 7.1 60.1 109.7 O K

2160 min Winter 100.064 0.064 43.3 2.2 45.6 45.7 O K

2880 min Winter 100.043 0.043 36.2 1.2 37.4 30.7 O K

4320 min Winter 100.032 0.032 26.6 0.7 27.3 22.5 O K

5760 min Winter 100.025 0.025 21.1 0.5 21.6 17.9 O K

7200 min Winter 100.021 0.021 17.8 0.4 18.2 15.1 O K

8640 min Winter 100.018 0.018 15.3 0.3 15.6 13.0 O K

10080 min Winter 100.016 0.016 13.6 0.2 13.8 11.5 O K

Storm

Event

Rain

(mm/hr)

Flooded

Volume

(m³)

Discharge

Volume

(m³)

Time-Peak

(mins)

360 min Winter 8.034 0.0 1619.4 230

480 min Winter 6.428 0.0 1727.5 296

600 min Winter 5.404 0.0 1815.3 360

720 min Winter 4.687 0.0 1889.6 422

960 min Winter 3.743 0.0 2012.0 544


2880 min Winter 1.577 0.0 2542.3 1460

4320 min Winter 1.143 0.0 2766.0 2188

5760 min Winter 0.910 0.0 2934.7 2904

7200 min Winter 0.762 0.0 3071.5 3616

8640 min Winter 0.659 0.0 3187.4 4248

10080 min Winter 0.583 0.0 3288.2 4992










Rainfall Details


Rainfall Model FSR Winter Storms YesReturn Period (years) 30 Cv (Summer) 0.750


M5-60 (mm) 20.000 Shortest Storm (mins) 15

Ratio R 0.400 Longest Storm (mins) 10080

Summer Storms Yes Climate Change % +0

Time Area Diagram

Total Area (ha) 4.000

Time

From:

(mins)

To:

Area

(ha)

Time

From:

(mins)

To:

Area

(ha)

0 4 2.000 4 8 2.000










Model Details



Lined Soakaway Structure

Infiltration Coefficient Base (m/hr) 0.20000 Ring Diameter (m) 0.90

Infiltration Coefficient Side (m/hr) 0.20000 Pit Multiplier 1.5

Safety Factor 2.0 Number Required 720

Porosity 0.30 Cap Volume Depth (m) 0.000

Invert Level (m) 100.000 Cap Infiltration Depth (m) 0.000

Hydro-Brake® Outflow Control




0.100 4.3 0.800 9.1 2.000 13.8 4.000 19.6 7.000 25.9

0.200 8.7 1.000 9.9 2.200 14.5 4.500 20.8 7.500 26.8

0.300 9.4 1.200 10.8 2.400 15.2 5.000 21.9 8.000 27.7

0.400 9.0 1.400 11.6 2.600 15.8 5.500 23.0 8.500 28.5

0.500 8.7 1.600 12.4 3.000 17.0 6.000 24.0 9.000 29.4

0.600 8.6 1.800 13.1 3.500 18.3 6.500 25.0 9.500 30.2








File Example10.casx Checked by

XP Solutions Source Control 2013.1.7

Cascade Summary of Results for Pond.srcx


Upstream Structures

Outflow To Overflow To

CarPark.srcx (None) (None)

Soakaways.srcx

Storm

Event

Max

Level

(m)

Max

Depth

(m)

Max

Control

(l/s)

Max

Overflow

(l/s)

Max

Σ Outflow

(l/s)

Max

Volume

(m³)

Status

15 min Summer 99.393 0.393 15.4 0.0 15.4 424.8 O K

30 min Summer 99.511 0.511 16.4 0.0 16.4 552.2 O K

60 min Summer 99.632 0.632 17.3 0.0 17.3 682.9 O K

120 min Summer 99.749 0.749 18.2 0.0 18.2 808.7 O K

180 min Summer 99.800 0.800 18.6 0.0 18.6 864.4 O K

240 min Summer 99.824 0.824 18.8 0.0 18.8 889.8 O K

360 min Summer 99.837 0.837 18.8 0.0 18.8 904.1 O K

480 min Summer 99.818 0.818 18.7 0.0 18.7 883.9 O K

600 min Summer 99.799 0.799 18.6 0.0 18.6 863.3 O K

720 min Summer 99.783 0.783 18.5 0.0 18.5 845.2 O K

960 min Summer 99.754 0.754 18.2 0.0 18.2 814.2 O K

1440 min Summer 99.689 0.689 17.8 0.0 17.8 744.3 O K

2160 min Summer 99.577 0.577 16.9 0.0 16.9 622.7 O K

2880 min Summer 99.480 0.480 16.1 0.0 16.1 518.5 O K

4320 min Summer 99.348 0.348 15.0 0.0 15.0 375.6 O K

5760 min Summer 99.249 0.249 14.1 0.0 14.1 269.1 O K

7200 min Summer 99.172 0.172 13.4 0.0 13.4 186.0 O K

8640 min Summer 99.113 0.113 12.8 0.0 12.8 121.9 O K

10080 min Summer 99.067 0.067 12.3 0.0 12.3 72.5 O K


60 min Winter 99.713 0.713 17.9 0.0 17.9 769.5 O K

120 min Winter 99.848 0.848 18.9 0.0 18.9 915.7 O K

Storm

Event

Rain

(mm/hr)

Flooded

Volume

(m³)

Discharge

Volume

(m³)

Overflow

Volume

(m³)

Time-Peak

(mins)

15 min Summer 76.035 0.0 499.1 0.0 36

30 min Summer 49.499 0.0 648.9 0.0 51

60 min Summer 30.811 0.0 806.1 0.0 70

120 min Summer 18.615 0.0 969.0 0.0 128

180 min Summer 13.715 0.0 1065.3 0.0 186

240 min Summer 10.995 0.0 1134.7 0.0 244

360 min Summer 8.034 0.0 1238.7 0.0 362

480 min Summer 6.428 0.0 1313.4 0.0 430

600 min Summer 5.404 0.0 1375.0 0.0 488

720 min Summer 4.687 0.0 1429.8 0.0 548

960 min Summer 3.743 0.0 1521.8 0.0 674

1440 min Summer 2.723 0.0 1644.6 0.0 938

2160 min Summer 1.979 0.0 1749.1 0.0 1344

2880 min Summer 1.577 0.0 1826.6 0.0 1736

4320 min Summer 1.143 0.0 1976.4 0.0 2512

5760 min Summer 0.910 0.0 2095.6 0.0 3232

7200 min Summer 0.762 0.0 2194.3 0.0 3960

8640 min Summer 0.659 0.0 2280.6 0.0 4664

10080 min Summer 0.583 0.0 2353.9 0.0 534415 min Winter 76.035 0.0 559.1 0.0 40

30 min Winter 49.499 0.0 728.0 0.0 56

60 min Winter 30.811 0.0 904.4 0.0 76

120 min Winter 18.615 0.0 1086.6 0.0 126










Cascade Summary of Results for Pond.srcx


Storm Event

MaxLevel

(m)

MaxDepth

(m)

MaxControl

(l/s)

MaxOverflow

(l/s)

MaxΣ Outflow

(l/s)

Max Volume

(m³)

Status

180 min Winter 99.913 0.913 19.4 0.0 19.4 985.7 O K

240 min Winter 99.941 0.941 19.6 0.0 19.6 1016.1 O K

360 min Winter 99.964 0.964 19.7 0.0 19.7 1041.3 O K

480 min Winter 99.961 0.961 19.7 0.0 19.7 1038.1 O K

600 min Winter 99.943 0.943 19.6 0.0 19.6 1018.4 O K

720 min Winter 99.928 0.928 19.5 0.0 19.5 1001.9 O K

960 min Winter 99.884 0.884 19.2 0.0 19.2 954.8 O K

1440 min Winter 99.764 0.764 18.3 0.0 18.3 824.9 O K

2160 min Winter 99.593 0.593 17.0 0.0 17.0 640.0 O K

2880 min Winter 99.479 0.479 16.1 0.0 16.1 517.8 O K

4320 min Winter 99.304 0.304 14.6 0.0 14.6 328.4 O K

5760 min Winter 99.174 0.174 13.4 0.0 13.4 188.1 O K

7200 min Winter 99.080 0.080 12.4 0.0 12.4 86.7 O K

8640 min Winter 99.018 0.018 11.7 0.0 11.7 19.0 O K

10080 min Winter 99.000 0.000 11.0 0.0 11.0 0.0 O K

Storm

Event

Rain

(mm/hr)

Flooded

Volume

(m³)

Discharge

Volume

(m³)

Overflow

Volume

(m³)

Time-Peak

(mins)

180 min Winter 13.715 0.0 1195.0 0.0 182

240 min Winter 10.995 0.0 1269.2 0.0 240

360 min Winter 8.034 0.0 1383.2 0.0 356


720 min Winter 4.687 0.0 1616.0 0.0 576

960 min Winter 3.743 0.0 1717.4 0.0 716

1440 min Winter 2.723 0.0 1827.3 0.0 1014

2160 min Winter 1.979 0.0 1922.6 0.0 1452

2880 min Winter 1.577 0.0 2034.1 0.0 1872

4320 min Winter 1.143 0.0 2210.3 0.0 2640

5760 min Winter 0.910 0.0 2345.5 0.0 3368

7200 min Winter 0.762 0.0 2455.4 0.0 4040

8640 min Winter 0.659 0.0 2551.5 0.0 4592

10080 min Winter 0.583 0.0 2634.1 0.0 0










Cascade Model Details for Pond.srcx



Tank or Pond Structure



0.000 1080.0

Crown Vortex Valve® Outflow Control

Design Head (m) 1.500 Vortex Valve® Type R1 SW Only Invert Level (m) 98.500



0.100 3.0 0.800 14.6 2.000 23.0 4.000 32.6 7.000 43.1

0.200 7.3 1.000 16.3 2.200 24.2 4.500 34.6 7.500 44.6

0.300 10.3 1.200 17.9 2.400 25.2 5.000 36.4 8.000 46.1

0.400 10.3 1.400 19.3 2.600 26.3 5.500 38.2 8.500 47.5

0.500 11.5 1.600 20.6 3.000 28.2 6.000 39.9 9.000 48.9

0.600 12.6 1.800 21.9 3.500 30.5 6.500 41.5 9.500 50.2

Weir Overflow Control






Example 11 - QuOSTQuantities & Costings




Introduction

QuOST saves the engineer time and money by automating the processes of

taking off, billing and pricing a job. In doing so, it also provides a quick

means of comparing the cost implications of various design options.

The QuOST module integrates with System 1 to produce costs and quantities

from the data it generates. All materials, pipe specifications and other key

variables are user-definable.

Specifications supported include CESMM, SMM, Method of Measurement

for Highway Works and the user's own specifications.

In this example we shall see how QuOST uses the parameters defined in a

Classification Library to classify each pipe and manhole in the system

automatically. We will also use QuOST to calculate the excavation volumes

for different construction methods and techniques. The example has three

phases:

• First we will call a file and use the default classifications to analyse thetaking off, etc.

• Then we will tailor our own set of classifications to our own companyneeds.

• Finally we will analyse the network again using the new classifications.

The analysis is very quick and as the classifications are saved they may

be used on other projects.




Opening QuOSTOpen QuOST by clicking on the icon in the Micro Drainage 2014 file, in

your start menu. You are presented with the QuOST Open screen.

Select Open Existing File by double clicking on the icon. The data for this

example is contained on your master program disk with the file name

Example11.mdx. This file will be copied to the hard disk of your PC when

you install Micro Drainage.

The first time you open a design in QuOST it is classified with the current

(default) library. To change the library, select Network Classifications from

the Network menu. Click the Classifications button on the NetworkClassifications toolbar.

Classifications

Click the Import icon and select the file Example11.tokx. The classifications

library is now loaded; this will be saved within Example11.mdx the next time

you save the file. Click the OK button.

A full breakdown of the job is immediately available; select Take Off Data

from the Results menu.

Take Off Data

A Windows Explorer-style screen appears, showing a summary of the Take

Off data. A full take off of the job is presented to you.




The data can be viewed in a number of ways, either as a summation of totals

of pipe / manhole types or as an individual breakdown of each pipe run,

manholes and materials.

If you expand the Project icon in the tree (by clicking the small +), a series of

sub-menus (branches) appear. These give you a breakdown for the project,enabling you to work with as much or as little detail as you require. Try

expanding different branches in the tree to see the different sets of data

available. Highlight an entry and the corresponding data is displayed on the

right of the screen.

The program has applied a classification from our library to each of the pipes

and manholes in the network based on a set of pre-defined rules. However it

is unlikely in a real job that the whole network will automatically be

classified correctly.




Network ClassificationsTo change any of the classifications, select Network Classifications from the

Network menu.

Network Classifications

A Pipe Type and Manhole Type can be chosen for each pipe in the network.

Click on the small arrow to see a list of all the available entries. There is an

entry on the list for each item in the Classification library. Try changing thePipe Type for Pipe 1.000.

The entry turns red. This is similar to System 1 and denotes user

specification. If the program chooses a class it is displayed in blue. Move the

cursor to the second pipe. The Pipe Class for Pipe 1.000 is shown on a yellow

background. QuOST allows the user to choose any of the available classes

for any location in the network. However if this breaks one of the rules

defined in the library the entry is highlighted in yellow. We will look at

defining classification rules later in this example.




To return the pipe to its original class select Re-classify from the list.

Most specifications require ground level data at a given interval between the

manholes. QuOST can divide the total length by up to ten intervals, with thefacility to assign ground levels to the intermediate chainages. These values

are taken into account when the volumes of excavation and pipe lengths for

different depth bandings are calculated.

Sometimes a pipe or manhole cannot be classified under any of the available

options. In this case the spreadsheet will display Re-classify and the user

should select the pipe or manhole type they wish to use.

QuOST incorporates many of the graphic features of Micro Drainage,including the Network Schematic and Longsections resources. These can be

accessed via the icons on the toolbar in the usual way, or from the Graphics

menu.

In this example we have based the taking off on Sewers For Adoption and

CESMM, as these dictate how the measurements are classified. The table can

be set up for any specification, and is split into seven different fields. These

are General Items, Pipes, Manholes, Depth bands, Miscellaneous, StorageStructures and Flow Controls. (The last two are only available if Simulation

is available).

The Classification LibraryOpen the Classification Library by selecting the Classifications Library

button from the Network Classifications toolbar.

Classifications Library




General classificationsThese settings cover the basic elements used in the construction of manholes

and pipelines. These include manhole cover types and the general materials

used, such as pipe surrounds and the concrete used for the construction of

manhole bases and the surrounds to the manhole rings.

As the table shows, in this example there are three different manhole covers

specified: heavy, medium and light. The description field allows a full

description of the cover to be entered for reference purposes. Each cover type

can be assigned to a different type of manhole classification.

The Material Types section allows the entry of all the different types of

materials that will be used. These may include the types of concrete andgranular surround for pipe bedding. Note that here we have specified all

concrete for the bases and manhole surrounds as Class C20 and that the pipe

bedding is either granular Type A or B.

To proceed, click on the Pipes tab.




PipesThe classification of the pipes is based on the diameter and the proposed

depth of construction. Most pipes are made either from clay or concrete. Clay

is generally used for smaller diameter pipes: 100, 150, 225, 300, 375 and 400

mm. Above 400 mm, clay becomes expensive and less robust. Accordingly,

concrete is used for pipes of 400 mm or greater.

The depth at which the pipe will be laid is also important in determining the

pipe specification. The deeper the pipe, the greater the external loading it will

have to bear.

Within CESMM (Civil Engineering Standard Method of Measurement) there

are eight different classes of pipe, all of which are available in the pipe

classification list. You can scroll through these using the arrows at the bottomof the page.

The Navigation Bar




The order of these groupings is critical for automatic classification. QuOST

tests each pipe in the network against each of the pipe classes, always

beginning with the first in the list. If this pipe does not match the

specification, it automatically moves to the next in the list. If no match is

found, the pipe will be deemed unclassified.

Controls are given to move records within the library, delete records or insert

copies. These are shown to the right of the navigation controls.

Record Controls

Since concrete pipes are the most common, concrete has been placed at the

beginning of the pipe Classification Table. The second classification isconduit sections, since most conduits sections are also made of concrete. The

third is clay pipes, which are set for lower pipe diameters.

A general pipe thickness can be entered for each type of pipe. This value is

used when calculating the volume for the pipe surround, since the widths of

the trenches are based on a dimension taken from the internal diameter of the

pipe. The volume of the outer diameter of the pipe is subtracted from the

volume of the trench to give the correct volume fill.

Cost per MetreThis allows the entry of a cost per metre run of the pipe. A total including the

cost per metre of the surround material can also be included. Note that the

excavation costs and replacement costs are entered on the Depths and

Miscellaneous pages.

Bedding/Surround DepthPipes are usually laid on a bed of smooth material to minimise the occurrence

of high point loads that could damage the pipes. There is a minimum

requirement for the depth of this bedding and for the thickness of the material

surrounding the top of the pipe.

Entering these two factors enables QuOST to calculate the total volume of

surround required for each pipe. In most cases, the material will be a granular

compound, though other materials are sometimes used. In particular, pipesthat are to be laid close to ground level are often encased in concrete for




added robustness. This specification can be changed by selecting

Classifications Library button from the Network Classifications toolbar.

The list box shows all the materials entered under the General section; click

on the arrow to see the list. You can then simply click on the relevantmaterial for the pipe classification in question.

Surround Material

Trench widths Naturally, trench widths vary according to the diameter of the pipe, although

minimum widths are usually specified. Most pipes are laid in trenches that

have vertical sides; i.e. the width at the bottom is the same as the width at the

top.

However, when pipes are laid very deep, the sides are usually sloped (or

'battered') to reduce the likelihood of collapsing. The last two fields can be

used to take account of this scenario.

Manholes This classification has been set up for Sewers for Adoption. Within this, there

are six manhole classifications: A, B, C, D, E and F. The classifications are

based on the depth and diameter of each manhole. Sewers for Adoption also

shows the arrangement of each classification, for example the amount of

concrete to be used in the surrounds and the bases.

In our example, the first manhole shown is Type A. This should be usedwhen the depth of pipe (to the soffit) is between 3 and 6 metres. These

manholes are therefore quite large and in our table we have specified that any

manhole greater than 1050 mm in diameter, and with a depth greater than 3

metres, will automatically be classed as a Type A.

Each of the remaining types has been set in accordance with Sewers for

Adoption. However, we have also included another type, classified Make it

C! This is classification 3 - use the scroll arrows to find it.




Most manholes used in drainage are circular, and System 1 specifies circular

manholes by default. However if the manhole is between 1 metre and 1.45

metres deep, then Sewers for Adoption states it should be a Type C manhole,

which is rectangular.

The Make it C! classification enables QuOST to highlight the anomaly, so

that you can decide either to make the manhole deeper or change it to the

correct size. A full list of the manholes falling into this category is given in

the breakdown section of QuOST.

Note: If you are not working with Sewers for Adoption, you can enter your

own specifications for the classifications you require.




Depths

As a rule of thumb, the deeper you lay a pipe, the more expensive it gets.

Depths, therefore, are a critical consideration when costing a job.

Because the pipes are laid on a gradient, they will usually pass through a

series of depth bands. The method of specifying the length of pipe allowable

between different depth band increments varies according to the specification

you are working to. In this example, the increments are 0.5 metres below a

depth of 1.5 metres, which is in line with CESMM.

QuOST will automatically calculate the length of pipe within each band. Ifyou enter the excavation cost per cubic metre for each band, the program will

also work out the total cost for this aspect of the job.




Miscellaneous

Here we find all the additional variables that contribute to the costs and

quantities of the job. These fields enable you to enter values for Blindingconcrete, the replacement of excavated material and the cost of removing the

material displaced by the pipe and its surround material. The Reinstatement

costs cover general landscaping and the Bulking Factor allows you to cost the

percentage increase in the volume of the material to be removed.




Storage Structures (Simulation only)

QuOST allows storage structures to be included in the costing. Each type of

storage structure can be individually priced based on cost per m3. The

infiltration structures can only be priced if Source Control is available.

Flow Controls (Simulation only)

QuOST also allows flow controls to be included in the costing. Each type of

control can be priced individually.




Building a classif ication table Now we will build our own classification table to a site-specific specification

(as set out below).

MD Pipe Specification

Pipe Type Strength

of Pipe

Diameters

(mm)

Pipe

Thickness

Min

Depth

Max

Depth

Clay Standard 100 - 375 50 0 1.200

Clay Super 100 – 375 75 1.200 2.000 *

Concrete Standard 375 – 1800 75 0 1.600

Concrete Super 375 - 1800 75 1.600 6.000

*Any pipe greater than 2 metres deep should be concrete

MD Manhole Specification

TYPE Cover

Type

Diameters

(mm)

Min

Depth

Max

Depth

1 Light 1050 – 1200 0 1.5

2 Medium 1200 + 1.0 2.0

3 Heavy 1350 – 1500 2.0 3.0

4 Heavy 1500 – 4000 2.0 4.0

All manhole bases shall be 300mm deep and have 75mm of blinding

concrete.

Trench Construction

Pipe Diameter(mm)

Trench Width(mm)

< 375 300 + pipe diameter

375 – 450 500 + pipe diameter



900 > 750 + pipe diameter




Depth BandsLengths of pipe will be classified in bands of 250mm below a depth of 1

metre.

Materials All clay pipes will be bedded and covered with surround type Agg 1 and all

concrete pipes will have surround type Agg 2, to a depth of 300mm above

and below the pipe. The concrete for manhole surrounds shall be 150mm

thick type Con 1 and the concrete used in pipe surrounds shall be type Con 2.

General Classes

To start entering a new Classification Library click the New icon. If a promptappears asking you to Save click No.

New Classification

Click on the General tab and you are ready to begin. From the specification

shown below, enter all the data referring to the manhole covers, together with

the materials used in the construction of the manholes and pipe runs. To do

this, simply click in the relevant field and type in the entry.




In this example we will not be specifying any unit costs for the project. Once

the data has been entered we can move on to the pipe entries by selecting the

Pipes tab.

Pipe ClassesThe specification has four types of pipes, but the trench width will vary

according to the pipe diameter. We will therefore specify six different entries

to accommodate the change in trench width for pipes over 900mm in

diameter.

For the first pipe, enter Clay - Standard Strength for diameters 100 – 375mm.

From the specification above, we can enter all the relevant data in the boxes

provided.

The entry for Surround Material is selected by using the drop down box.

Click on the arrow and the program will give you the range of materials you

specified in the General Items. For the first pipe class, choose Agg 1.

When the data entry is complete click the New Record button to save this

classification and move onto the next one.

New Record




Alternatively use the Copy button to produce an identical record to the one

you've just entered. This limits data entry if several classes share similar

characteristics.

Copy

Proceed to enter the data for the other 5 pipe classes as shown.




Note: We have used the postfix T1 and T2 to distinguish between the two

different trench widths. It is important to use different names so that we

can tell which classification has been used to generate the Taking Offinformation.

Manhole ClassesThe specification contains four types of manholes. QuOST will dynamically

change the type of manhole based on the diameter and depth of the pipe.

All the manholes on this project are circular, so we need only insert the data

for the minimum and maximum diameters, together with construction details

such as surround thickness, base depths and so on. Use the drop-down menus

to select the correct cover type and material type for each manhole.

As before, use the arrows to move to the next entries, or use Copy and amend

the data to suit each manhole type.




Depth BandsQuOST will automatically calculate the length of each pipe run that falls

within each individual banding. The specification states that pipes at a depth

of less than 1 metre from ground level to the invert shall be classified in one

band. After 1 metre, the banding increments go up in steps of 250mm. Enter

the data as shown.




Miscellaneous Items, Storage Structuresand Flow Controls

Here we can specify costs for the excavated material. We cost the volume forreplacement and removal, but we also specify a reinstatement cost per square

metre. This function is useful for the reinstatement of roads or verges.

A price for blinding concrete can also be assigned, in addition to a bulking

factor, expressed as a percentage.

Costs for storage structures and flow controls can also be specified in the

respective tabs allowing the whole design to be priced.

We are not producing costings for this example so all the entries can be left

as 0.




Re-ClassifyThe classifications library can be saved and used on future projects by

clicking on Export and enter the file name as Example11a.tokx.

Export

Then click OK to proceed.

The Storm file we loaded at the beginning of this example will still be open.

QuOST will have automatically applied the new library and produced new

Taking Off information.

When you open the Taking Off information you are presented with a

warning.

Network ClassificationsTo see how the classifications have been applied and which pipes are

unclassified open the Network Classifications.

Network Classifications.

As you scroll through the network classifications sheet you will see that

QuOST has assigned the correct pipe type and manhole type for each piperun. You will also notice that there are a number of pipes that do not have a

pipe or a manhole assigned to them. Indeed, in two cases there is neither a

pipe classification nor a manhole type specified.

In these cases the pipes have fallen between the classifications. We can now

look into these cases in more depth and assign the classifications manually.




Unclassified Pipes

Pipes 4.002, 4.003, 4.004 and 5.004 have no pipe types assigned to them.

Pipes 4.002, 4.003, 4.004 and 5.004These pipes are all 225mm diameter and have depths greater than 2m. In the

classification table, we have specified clay pipes to be assigned for depths

less than 2m. However, the maximum depth for these four pipes is 2.419m.

Click on the Classifications icon again.

Classifications

Click on the Pipes tab and use the cursor buttons to move to the second entry

(Clay – Super Strength). Change the maximum depth from 2.000m to

2.500m. Then click OK. The Network Classifications shows that all the

pipes have now been classified.

Unclassified ManholesManholes 24 and 25 are also unclassified. These two manholes do not fall

within a classification range and are both 1200mm in diameter. In the

manhole classification table, 1200mm manholes are classified as Type 2, but

the maximum depth has been set to 2m.

Accordingly, we will manually select Type 2 for these manholes by clicking

on Type 2 in the drop down box.

The manholes are highlighted in yellow to indicate that they do not fulfil the

specified rules. (It may be appropriate to return to System 1 and alter the

manhole diameters to 1350mm and use a Type 3 manhole).

All the pipes and manholes have now been assigned a type and theclassifications are satisfactory.




Taking OffWhen you are satisfied that all the specifications and classifications are

correct, you can view the Taking Off data.

Select Take Off Data from the Results menu.

Take Off Data

This time there is no warning as all the pipes and manholes have been

classified. It is important that the Taking Off information is not used whilst

this warning is present. Totals for pipe lengths, excavation volumes etc do

not take unclassified entries into account!

The data can be calculated by defining the lengths of pipe runs in two

different formats.

In the toolbar menu, use the pull down menu for Length Calc's based on to

switch between Centre-Centre and True Length. Centre-Centre is the length

calculated from the centre of one manhole to the centre of the other manhole.

True Length is the actual length of pipe, measured from the inside faces of

the manholes.




ProjectThe breakdown for the project gives an overview of the design as a whole,

with total numbers of pipes, total length and an overview of the volume of

the pipe capacity. A summation of manholes is also given, showing the

number, the accumulated depth and the total volume in the manholes.

TotalsThe subheadings under the Totals listing give a complete summation for each

classification. Total lengths, numbers and volumes are all given. Click on the

Totals menu to view the totals for manholes and pipes.

BreakdownBreakdown will give you a fully itemised bill of all the pipes, manholes and

material, broken down either by size or by class. It also gives locations,

lengths and depths. Open the Breakdown folder and have a look at the

entries.

Finally click on the Ground Works folder under Breakdown and select Depth

Bands. You will now be presented with a full breakdown for every pipe,

showing how much of that individual pipe falls within each depth band. This

is shown instantly, eliminating a costly and time-consuming manual task thathas been the scourge of engineers and technicians for years.





West Street QuOST

Newbury RG14 1BD Quantities & Costings




Classification


Classification Example Specification

Currency Symbol £

Manhole Covers

Name Description

Light Light Duty, residential only

Medium Medium Duty, light traffic

Heavy Heavy Duty, main roads

Material Types

Name Cost (£/m³) Description

Con 1 0.00 Concrete for manholes

Con 2 0.00 Concrete for pipes

Agg 1 0.00 Surround for clay pipes

Agg 2 0.00 Surround for concrete pipes

Pipe Types

Name / Description Clay - Standard strength

Design Diameter Min/Max (mm) 100 / 375

Cover Depth for Pipe Min/Max (m) 0 / 1.2

Pipe Thickness (mm) 50

Cost (£/m) 0

Bedding / Surround Depth below pipe (mm) 300

Bedding / Surround Depth above pipe (mm) 300

Surround Material Agg 1

Trench Width at base : D + mm 300

Trench Width at cover : D + mm 300

Trench Depth at Width change (m) 0

Working Surface : D + mm 300

Name / Description Clay - Super Strength


Cover Depth for Pipe Min/Max (m) 1.2 / 2.5

Pipe Thickness (mm) 75Cost (£/m) 0








Name / Description Concrete - Standard - T1




Cost (£/m) 0









West Street QuOST





Pipe Types





Name / Description Concrete - Standard - T2




Cost (£/m) 0





Trench Width at cover : D + mm 750Trench Depth at Width change (m) 0


Name / Description Concrete - Super - T1


Cover Depth for Pipe Min/Max (m) 1.6 / 6


Cost (£/m) 0








Name / Description Concrete - Super - T2


Cover Depth for Pipe Min/Max (m) 1.6 / 6


Cost (£/m) 0






Trench Depth at Width change (m) 0Working Surface : D + mm 750

Manhole Types

Name / Description TYPE 1

Internal Diameter Min/Max (mm) 1050 / 1200

Internal Width Min/Max (mm) 0 / 0

Ring Depth Min/Max (m) 0 / 1.5

Cover Type Light

Cost (£/m deep) 0

Ring Thickness (mm) 150

Surround Material Con 1

Surround Thickness (mm) 150

Base Height (mm) 300

Base Material Con 1

Blinding Height (mm) 75

Additional Costs (£) 0





West Street QuOST





Manhole Types





Ring Depth Min/Max (m) 1 / 2

Cover Type Medium

Cost (£/m deep) 0





Base Material Con 1







Cover Type Heavy

Cost (£/m deep) 0





Base Material Con 1







Cover Type Heavy

Cost (£/m deep) 0





Base Material Con 1

Blinding Height (mm) 75Additional Costs (£) 0

Depth Bands

Depth <= (m) Excavation Cost (£/m³)

1.000 0.00

1.250 0.00

1.500 0.00

1.750 0.00

2.000 0.00

2.250 0.00

2.500 0.002.750 0.00

3.000 0.00

3.250 0.00

3.500 0.00





West Street QuOST





Depth Bands


3.750 0.00

4.000 0.00

Depth <= (m) Excavation Cost (£/m³)

Miscellaneous

MH Blinding Cost (£/m³) 0.00

Replacement Cost (£/m³) 0.00

Removal Cost (£/m³) 0.00

Reinstatement Cost (£/m²) 0.00

Bulking Factor (%) 0.00

Storage Structure Costs

Cost (£/m³) Cost (£/m³)

Pipe 0.00

Tank or Pond 0.00

Box Culvert 0.00

Double Pipe 0.00

Double Box Culvert 0.00

Lined Soakaway 0.00

House Soakaway 0.00

Infiltration Trench 0.00

Trench Soakaway 0.00

Swale 0.00

Infiltration Basin 0.00

Infiltration Blanket 0.00

Porous Car Park 0.00

Cellular Storage 0.00

Dry Swale 0.00

Filter Drain 0.00

Bio-Retention Area 0.00

Sand Filter 0.00

Flow Control Costs

Name Cost (£/unit)

Weir 0.00

Orifice 0.00

Gate 0.00

Depth/Flow Relationship 0.00

Pipe 0.00

V-Notch Weir 0.00

Pump 0.00

Hydro-Brake® 0.00

Crown Vortex Valve® 0.00

Filtration 0.00

Garastor 0.00

Level Controlled Pump 0.00

Siphon 0.00

Flap Valve 0.00

Non Return Valve 0.00

ACO Q-Brake 0.00

Hydroslide 0.00





West Street QuOST

Newbury RG14 1BD Quantities and Costings




Network Classifications for Example11


PN USMH

Name

Pipe

Dia

(mm)

Min Cover

Depth

(m)

Max Cover

Depth

(m)

Pipe Type MH

Dia

(mm)

MH

Width

(mm)

MH Ring

Depth

(m)

MH Type

1.000 1 300 0.900 1.010 Clay - Standard strength 1050 0 0.900 TYPE 1

1.001 2 375 1.010 1.046 Clay - Standard strength 1350 0 1.010 TYPE 2

1.002 3 375 1.046 1.646 Clay - Super Strength 1350 0 1.046 TYPE 2





1.004 8 450 1.531 1.667 Concrete - Super - T1 1350 0 1.667 TYPE 2

1.005 9 450 1.531 1.554 Concrete - Standard - T1 1350 0 1.531 TYPE 2


1.007 11 600 1.674 1.739 Concrete - Super - T1 1500 0 1.674 TYPE 21.008 12 600 1.667 1.739 Concrete - Super - T1 1500 0 1.739 TYPE 2




























Example 12 – DrawNet(CAD)Working within AutoCAD

®




Introduction

In this example we will cover the key elements of working with

DrawNet(CAD) from setting up a network through to hydraulic analysis ofthe network using Micro Drainage software.

In creating this example we have assumed that you have a basic working

knowledge of AutoCAD, as well as the System 1 and Simulation modules

within Micro Drainage. All the co-ordinates quoted are approximate; it is not

essential for you to be millimetre-perfect in your selections. This example has

been created using AutoCAD 2013 within Windows 7; there may be some

variation between your screen and those featured here.




Loading DrawNet(CAD)Open DrawNet(CAD) using your preferred Windows option. DrawNet(CAD)

automatically loads within an AutoCAD profile specified during installation,

with the familiar AutoCAD welcome screen followed by a new, unnameddocument. From AutoCAD’s File menu, choose Open and choose

Example.dwg from the \DrawNet(CAD) 2014\Data directory.

The drawing below will be displayed.




One we made earl ier Now enlarge the top left-hand corner of the drawing (co-ordinates 55,370 to

the bottom left and 200,500 to the top right) by using AutoCAD's Zoom

command.

Note the blue dotted line within the highway, which shows where the pipe

network is to be placed. It has been put there to make it easier for you as you

familiarise yourself with the functions of DrawNet(CAD).

We will be following the line to create the network. The line has been drawn

with 3D co-ordinates (i.e. the 'z' co-ordinates) at the start and endpoints of

each section.

Remember that ordinary OS plans are not usually created in 3D, although the

'z' co-ordinate can be added in DrawNet(CAD), if it is known.

Other sources of drawings, such as surveys, highway layouts, architects'

layouts and others, are quite often in 3D, which is very helpful in developing

the drainage network.




Creating the networkWe want to draw a Storm network over the AutoCAD drawing which

indicates the locations of pipes and manholes.

Select Load from the Site menu, as this is the first time a DrawNet(CAD)

command has been run within this drawing you will be presented with the

DrawNet(CAD) Open box.

Select New Storm and enter the Design Criteria for your Storm network as below in the same way as you would in System1:




You can now start designing your Storm network. To setup a Foul or

Existing network(s) you can follow the same procedure as previously and

select the required Network type (please note that Existing Network(s) do not

require Design Criteria)

To change Network Type or Name you can load up the Network Manager in

the Site menu. You can add/remove Networks and edit a number of options

by using the Network Manager. The current Network will be highlighted in

light blue.

In this example we have used the (unoriginal) name Storm. Tick the Ask for

levels and accept the other settings by closing the form.




Creating a Network

Once your Design Criteria has been entered and you have closed the Network

Manager you are ready to start designing your network. Click on Define Pipe in the Create/Edit menu.

You are prompted to enter the Upstream Manhole (USMH) position. Movethe crosshairs to the beginning of the blue line in the top left hand corner of

the screen.

'Pick' the end of the line by clicking as near to the end as you can with the left

hand mouse button – you can use the same Object Snap options as you have

loaded into AutoCAD to snap to Endpoint/Midpoint etc..

Cover Levels will be read from the drawing and you can press the Enter key

to apply this level. Note that you can enter a cover level if the automatic

value is different. DrawNet(CAD) now prompts you for the next manhole

location. Each time a manhole is positioned, accept the default cover level by

pressing the Enter key.




Follow the blue lines to the Outfall location to the South and to complete the

network click the right hand mouse button and select the Close option from

the menu to end the network building session. This will result in 4 pipes,

1.000 – 1.003, as shown below.

You will see that DrawNet(CAD) draws the Network to match the Display

Settings in the Graphics menu. The pipes and manholes are numbered

automatically starting at the head of the line and working downstream to the

outfall. For drawing clarity you can reduce the pipe/manhole text size on the Network Settings Tab. To do this change the Text Height to 2m and click

Apply.

Entering a new branchAs before use the Define Pipe command and pick the location using the

crosshairs and the left hand mouse button. It is, of course, at the end of the

branch running down the 'cul de sac' of the road south west of the

downstream end of pipe 1.000 (co-ordinates approximately 75,430).

Note: You may find it quicker to define the main run of your Network

and then choose “New” once you have reached your Outfall and continue

to define any Branch Lines.

At the Enter Downstream End command, click once more on the intersection

at the downstream end of pipe 1.000 and the new branch is created for you.




The new pipe is shown, together with its

manhole. DrawNet(CAD)'s automatic

numbering system designates the pipe

number 2.000.

Amend NetworkWe shall demonstrate the error correction facilities within DrawNet(CAD) by

removing and then replacing pipe 1.003.

Deleting a pipeTo remove a pipe from your network just click on the pipe and hit the

“Delete” button. If you have a large network you can use the Goto Pipe

under the Site menu and select the network and pipe number from the drop

down lists provided to find the Pipe.

Select Pipe 1.003 by left-clicking on mouse and hit the Delete button.

Pipe 1.003 is deleted from the network and DrawNet(CAD) automatically

renumbers the network for you.

Re-inserting a pipeTo re-insert pipe 1.003, select Define Pipe from the Create/Edit menu. At the

command for Enter the USMH position click at the downstream end of 1.002.

Then click at the fork as before and accept the cover level suggested.

Again, right click the drawing and select the Close option from the menu.

DrawNet(CAD) will automatically renumber the new pipe 1.003.




Inserting a manholeWe require another manhole halfway along pipe 1.001, this can easily be

achieved by selecting the Insert Manhole option from the Create/Edit menu.

Once again the crosshairs disappear and your cursor becomes a small box.

DrawNet(CAD) prompts you to Select pipe to insert a Manhole half way

along its length and watch as DrawNet(CAD) inserts a new pipe and manhole

then renumbers the network.

Move ManholeIt is possible to move manholes within your network simply by clicking on

them and dragging them to a new location. However for ease there is also a

Move Manhole command located in the Create/Edit menu. First of all Select

Manhole S3, at the US end of 1.003, and delete it by pressing the Delete key

with it selected. This will have the effect of deleting pipe 1.002 updating the

network as shown below.

Use the Move Manhole command to select the downstream manhole of pipe

1.001. This, of course, is connected to pipe 1.002 as well. It may be necessary

to use AutoCAD's zoom facility to get closer to the manhole in order to select

it.




When you have selected the manhole, you are prompted to pick a new

location for the manhole. Pick the intersection of the three blue dotted lines

where manhole S3 was deleted from and DrawNet(CAD) moves the manhole

to the new position and updates the connecting pipes.

Examining the networkThe next stage is to look at some of the pipelines in more detail. To do this,

select Display DrawNet Properties from the Create/Edit menu. Alternatively

you can call up DrawNet Properties by right-clicking the mouse when a

DrawNet(CAD) entity is selected




Once the DrawNet Properties box has been loaded up you are able to view a

variety of details relating to the selected DrawNet(CAD) entity. The

Properties box is re-sizeable and can be set to auto-hide by pushing the pin

button on/off in the top right corner

You can view the properties on different entities by hitting Esc and selecting

another entity.

In the Properties box you choose additional annotation information to be

displayed against a Pipe or Manhole. Simply tick/un-tick any additional

information you want to display in the left hand column.

You can also edit details directly without the need to go back to the NetworkDetails. As per System1 any changes made to the network will result in the

Storm/Foul networks being redesigned accordingly.

Defining areas

There are two ways of defining a contributing area to a pipe. They can bedrawn out and assigned to a pipe or a known figure can be entered directly

via the Network Details or DrawNet Properties box against the pipe.

Storm and Existing Networks use Impermeable area rather than contributing

area as used by Foul networks. To this end when graphically defining areas

for Storm/Existing networks they will have a Percentage Impermeable

(PIMP) associated with them. i.e. 50% impermeable. When an Area is

defined you will be presented with three options for defining the PIMP:




• User - A user specified PIMP value can be entered

• Classification – PIMP value is obtained from a PIMP Classification.

• As Zoned – PIMP value is determined from intersections with thePIMP Zones that have been specified.

For the purposes of this example we will use the User and PIMP

Classifications approaches. Further information on the PIMP Zones approach

can be found in the Help.

Setting the PIMP ClassificationsTo define the PIMP Classifications, go to the Site menu and from it select

PIMP Classifications. DrawNet(CAD) will display the PIMP Classifications

dialog box.

For this example we will define three additional PIMP Classifications: Roof,

Road and Grass.

Click the Add PIMP Classification button.

Add PIMP Classification

In the PIMP Name box enter Roof and a value of 90 in the PIMP (%) box.

Press the Add PIMP Classification button again enter Road and a value of 80.

Finally enter Grass and a value of 25 for the third paved area factor.

Finally setup the PIMP Classification colours to match below by clicking onthe Area Colour and selecting a colour. To change the Area Hatch Pattern




click on the “…” button and select a new hatch pattern. The PIMP

Classifications should be as shown below.

Click OK to close the PIMP Classifications dialogue box.

Marking out an areaSelect Define Areas from the Create/Edit menu. The crosshairs disappear

and are replaced by the pick box, while you are prompted to select a pipe or

upstream manhole.

Move the box over any part of pipe 1.000 and click with the left hand mouse

button.

DrawNet(CAD) prompts you to Enter PIMP

Type for Area with the default value being

“User”. Accept this by pressing Return and you

are invited to trace the outline of the area for pipe 1.000.

Move the crosshairs to location 15,495 and click with the left hand mouse

button. Next, click location 130,495. DrawNet(CAD) draws a line between

the two points chosen.

Now move to 50,460 and click there. Click the right hand mouse button andselect the Close option from the menu to close the polygon.




DrawNet(CAD) defines the area with a green line, but also calculates

automatically the gross area enclosed by the polygon and applies the PIMP %

(100) to calculate the Impermeable Area. The PIMP value can then be

changed via the DrawNet Properties box with the Area selected.

Repeat the Define Areas command and select pipe 1.001 but this time select

Classification as the PIMP Type. You can now select the Roof Classification

by click on it or entering ‘1’ at the command prompt.

Note: Although it is important to put the start and endpoints of each

pipeline in the correct place, it is not important to trace the area to a high

level of accuracy. This is because the area will be divided by 10,000 to

convert it into hectares. Therefore, an accuracy of less than 10m2 isinsignificant when it comes to calculating the pipe diameters.




Trace the roof area using the following co-ordinates:

95.450 , 478.950

100.150 , 484.800

117.450 , 470.800112.750 , 465.000

After defining the last co-ordinate, select New from the right hand mouse

button menu. The default PIMP Type value will now be Classification,

accept this and then choose the Road Classification.

We are now going to trace the road area near the houses that we have just

traced. Trace the driveways of these houses using the following co-ordinates:

95.450 , 478.950

113.000 , 465.000

105.000 , 455.000

90.000 , 470.000

After defining the last co-ordinate, select New from the right hand mouse

button menu, accept Classification once more and select the Grass Classification.

Finally trace out the grassed area behind the houses at the following co-

ordinates:

100.150 , 485.800

115.000 , 500.000

135.000 , 480.000

120.000 , 470.000




After clicking on the last co-ordinate, select Close from the right hand mouse

button menu. You will see that each of the areas now follows the colour

selected for the PIMP Classification. If you do not see the hatches these can

be turned on via the Display Settings.

Click on the Area Summary button in the Results menu and DrawNet(CAD)

will display a summary of all the areas defined.

To complete this process, define a single User area for pipe 2.000, using the

following co-ordinates:

50.000 , 460.000

110.000 , 420.000

70.000 , 390.000

40.000 , 410.000

After clicking on the last co-ordinate, select Close from the right hand mouse

button menu.




Amending and editing dataA major benefit of DrawNet(CAD) is the speed and ease with which the

network design can be altered. The following exercises demonstrate these

procedures.

Renumbering pipesDrawNet(CAD) has its own automatic renumbering facility. This allows it to

renumber the entire network by interrogating the database.

To demonstrate this function select the Renumber Network option from the

Network menu.

DrawNet(CAD) will automatically renumber the network starting at the

indicated Main Line number with the Value set as below

The network is renumbered as shown below.




The renumbering process is a very important facility as it provides a

continuity check on the upstream and downstream ends of every pipe in the

system.

In a real project, before you end the drawing, or attempt to enter MicroDrainage from the drawing, it is essential that you use DrawNet(CAD) to

carry out a successful renumber.

Repeat the renumber, choosing pipe 56.000 as the starting pipe and enter 1 as

the starting pipe number.

Outfall DetailsOpen the Outfall Details from the Network menu. The Outfall IL is currently

very deep in the ground. We will solve this when we have examined the

Network Details. Enter the outfall name and manhole diameter as shown

below then click OK .

Network DetailsTo view the Network Details select the Network Details commands from the

Network Menu. This will display the same Network Details form as you may

be familiar with from System1.

Examination of the spreadsheet will give you a series of warnings about

cover levels, culminating with the warning that the cover to the preceding

pipe is greater than 2.4. You can ignore all of these warnings, since Optimise

will take care of the cover to the system. However, take a look at the

Longsection to see the nature of the problem.




To complete the design of the system, click on the Optimise button and say

Yes to the Optimise message that appears. Storm automatically re-designs the

system.

Optimise

Clicking the Longsection button will show you the re-designed system. The

Auto Design options are only shown if A.P.T is installed.

Switching to Micro DrainageDrawNet(CAD) provides an automatic link to Micro Drainage to enable you

to analyse the network. In this example we have assumed that Micro

Drainage is running on the same machine as DrawNet(CAD), or that you

have access to it via a network.

Note: If you do not have Micro Drainage installed, you will need to take

the Storm.mdx file and transfer it to the machine, which Micro Drainage is

running on.

Writing to Micro DrainageFrom the DrawNet(CAD) menu, select Save from the Site menu option. This

will display the Save File dialogue. You need to specify a File name and a

location to save the file. In this example we have used the filenameStorm.mdx.




Running NetworkWe will now launch to Network to perform a hydrographic analysis of the

file with the Simulation module. To do this open the Module Selector fromthe Help/About menu, click on the Network icon and the software will be

opened as a new window.

Note: If you are not familiar with switching modules please see How Do I

Use the Module Selector for more information.

At Open Dialog locate and load in the Storm.mdx file we saved previously.

Then open Simulation Criteria from the Site menu, enter 30 for the Return

Period and accept the remaining default values by clicking OK .

Before proceeding to analyse the network, set an on-line control. To do this,

select Online Controls from the Network menu or click on the Online

Controls icon.

Online Controls

Enter the control as shown below:




You will need to enter the value of 0.150 for the orifice diameter. Click OK

to close the form.

Analysis Now run the analysis At Fine time step and save the data. Your data will be

similar to those shown here.

Reading from Micro DrainageTo complete the tasks within Micro Drainage, select Save from the File

menu. Then exit Network and return to AutoCAD.

Opening the Network file

Choose Load Drainage Design option from the Site menu. The Open File dialogue box will appear. Simply select the Storm.mdx file and select Open

to load your network file into AutoCAD. You will be warned that the

Drawing already contains DrawNet(CAD) data, please say Yes to the

message to overwrite the old data.

Results of the analysis can be viewed in DrawNet(CAD) by opening the

Simulation Summary from the Results menu.

Simulation FlagsYou will see DrawNet(CAD) redraw the network, however at this stage no

changes will be apparent as we did not make any changes to the layout in

Network. However we can now turn on Simulation Flags to indicate the

result within the Drawing. To do this open the Display Settings from the

Graphics menu and toggle the Show Sim Flags option on in the Network

Settings tab.




The colour coding follows the colours on the Status tab of the Display

Settings, but by default they are coloured as:

Cyan OK

Red Surcharged

Magenta Flood Risk

Blue Flood

Viewing Simulation Data Return to the DrawNet(CAD) menu and choose Display DrawNet Properties

from the Create/Edit menu. You can click on a Pipe or Manhole DrawNet

entity, select the Simulation Data tab to view the Simulation attributes for the

chosen pipe. The sample here shows the Simulation Data for pipe S1.001.




LongsectionsFrom the Graphics menu we will next choose the Plot Longsection option.

DrawNet(CAD) will display the Plot dialogue box .

The Plot Designer can be used to display different variables on the

Longsection to suit the job requirements.

For this example, use the pick buttons to select the starting pipe 1.000 and the

last length to be pipe 1.003.

Enter the Horizontal / Vertical Scale as shown. In a real project, you could

select whichever value is appropriate.




You can now plot this longsection by clicking OK.

To return to the network close the current drawing by selecting Close from

AutoCAD’s File menu.

You have now completed this part of the example. If you simply quit from

AutoCAD, you should ensure that the example file is saved in its originalformat. If you want to save your work without altering the original, use the

Save As command and enter the name of your choice.




Redesigning the displayDrawNet(CAD) allows you to present the display in a variety of forms. This

exercise will introduce you to the controls so that in future you can tailor the

presentation of the drawings to suit your own preferences.

Select the Display Settings options from the Graphics menu and the

DrawNet(CAD) Display Settings dialogue box appears.

Change the Pipe Text Colour to Blue and click the Apply button to update the

screen display.

The Pipe Prefix can be changed to PN on the Network Manager form in the

Site menu.

Trial and error with the variables will help you to find your preferred

combination of options.




Pipe Crossing and Conflict DetectionDrawNet(CAD) enables you to identify instances where network designs

conflict with one another. To experiment with this facility, we must first load

the Foul file that contains the network that clashes with the existing Stormnetwork.

From the Site menu open the Network Manager and select the Import button.

Select the file Foul.mdx file to load and import the network as New Network

when prompted.

In the Network Manager the Storm and Foul networks are listed with the

Foul network highlighted light blue to indicate it is the current network.

The Storm and Foul networks cross at Pipes 1.000 and Pipe 2.000.




To examine this more closely choose Crossings and Conflicts from the Site

menu.

Networks can be included or supressed in Crossing and Conflict detection by

selecting or de-selecting from the Crossing and Conflict Filter. Separation

values for determining crossings and conflicts can also be specified.





Example 13 - DrawNetGraphical Model Build




IntroductionDrawNet allows multiple networks to be defined through a fully interactive

graphical interface. It allows Storm, Foul and, with A.P.T., Existing networks

to be designed on a single drawing. Storm and Existing networks may beexported to the Simulation module for full hydraulic testing. The following

example represents a typical process of using DrawNet to produce drawings

and design networks.

Select the Start button and open the Micro Drainage 2014 menu from within

the Programs menu and select Network .

Once Network has loaded, the program will prompt the following:

Click on New Storm.

You will now be presented with the Design Criteria screen. Enter the data as

shown overleaf and click OK .




Terrain Modelling

As the design is carried out graphically in DrawNet the Plan view will

automatically be loaded.

A DXF or DWG drawing file can be loaded onto the drawing. Click the Load

DXF button to load in a CAD file.

Load DXF

Click the Load button on the Import CAD Drawing form and open the

Example13.dxf file from the \Micro Drainage 2014\Data directory.

DrawNet supports two full terrain models. Proposed represents design or

built levels; these are the same as the cover levels normally entered in System

1. Existing levels are those on-site before development commences.

When APT is present DrawNet can extract cover level data from AutoCAD

DXF and DWG files to generate either of the two terrain models. The

example can still be completed if APT is not present as manual entry of cover

levels is explained later.




The CAD file and data will be loaded into the form. Tick the box to include

Site Survey Data as Proposed and Existing but not Image, set it to Simple

Cover and click OK .

The CAD file will be loaded onto the Plan view with the correct co-ordinates

and the ground data contained within the DXF will automatically be

triangulated. Turn off the TIN from the View Options dropdown.




The file also contains a proposed road layout for the site, which will be used

to design the preliminary drainage layout. Click the 3D WorldView button to

view the ground profile in 3D.

3D WorldView

A full 3D ground profile is generated. Make sure the Ground Overlay On

Ground option is ticked under the View tab and the Show TIN Ground option

is ticked under the Model tab. Under the Model tab increase the Overlay

Detail to 1024 and reduce the Horizontal Compression to 5:1.

Close the 3D to return to the Plan view. To make the road layout clearer to

work with, turn off GIS Ground options from the View Options dropdown

toolbar.




Draw Network

From the toolbar click on the Toolbox button to load the drawing Toolbox.

Toolbox

Right click anywhere on the Plan view and select the Band Zoom option

from the pop-up menu.

Left click with the mouse just to the top left of the drawing and drag a

window over the drawing as shown.

From the Toolbox select the Define Straight Pipes option.

Define Straight Pipes

Move the mouse over the drawing and a hand with a cross hair will appear.

Before drawing the network turn on the DXF Snap and Optimise options.

DXF Snap

Optimise On




In this example manhole positions are included in the CAD drawing and

should be retained, although manholes can be positioned freehand if required.

Move the hand over the proposed manhole position at the bottom left of the

drawing and a blue square appears as the mouse snaps to the manhole

location. Left click with the mouse to start drawing the network.

Proceed down the road to the next proposed manhole position and the square

will appear again. Left click with the mouse to draw the first pipe.

Continue down the road clicking on each manhole location and turn left to

the outfall at the end of the road. Right click with the mouse to end the main

run.

From the Toolbox click the Select button and a cross hair will appear.

Select

Move the cross hair over the last pipe until the Pipe S1.012 pop-up appears

and left click on it so it is highlighted red.

Open the Longsections from the Graphics menu. Optimise has automaticallydesigned the pipes to the ground profile.

Return to the Plan view.




To add a branch line to the network select the Band Zoom option as before

and draw a window as shown.

Select Define Straight Pipes from the Toolbox and move the hand to the top

manhole. Draw the pipes for the branch line and left click on Manhole S8 to

join it to the main line.

Note: Manholes can be renumbered using the Renumber Manholes button

on the bottom toolbar.

Click the Extents button to view the whole network.

Extents

Adding Areas

To add contributing areas to each manhole select the Define Areas button

from the Toolbox. Move the mouse over the drawing and a bullseye will

appear.

Define Areas

Move the bullseye over Manhole S1 and left click.




The hand and cross hair will appear. Move the hand to the far left of the area

contributing as shown and left click with the mouse.

Trace around the area in a clockwise direction to the point shown below.

Right click to close the area. Left click anywhere on the screen and the area

will be shown in green.




Click the Select button on the Toolbox and Left click on the area so it turns

red. Then Right click on the area and choose Properties.

Properties

The Properties form will appear showing all the details for the selected area.

Set the Transparency (%) to 100.

Note: A Paved Area Factor can also be specified at this point, which will be

applied to each area as it is added.

Draw around the area contributing to the branch line in the same way as

before adding it to Manhole S8 (upstream of pipe S2.000) and set theTransparency (%) to 100.

As the areas are added the network is recalculated and updated pipe sizes are

shown on the longsection.




Return to the Plan view.

Flow Controls

From the Toolbox click the Select button and left click on pipe S1.012 (so it

is highlighted red). Then right click and select Properties to show all the

information for pipe S1.012.

Scroll down to the bottom of the Properties. The flow for pipe S1.012 is

110.8 l/s, which is too high as there is a discharge consent of 20 l/s off site.

DrawNet allows a flow control to be specified. This facility will reduce the

flow to the required discharge and allow System 1 to reduce pipes

downstream.

Enter 20 l/s in the Design Flow (l/s) cell and press the Enter key on the

keyboard.

Note: Specifying a flow control is only available if APT present.

Although the flow for pipe S1.012 has been overruled the program will not

specify a pipe diameter smaller than the pipe immediately upstream. To

downsize the pipe, the diameter must be specified manually.

Note: The control must be specified in detail in Simulation as a constant

flow specification is not sufficient for a full analysis.




Network Details

The network can still be viewed in spreadsheet format if required. Select

Network Details from the Network menu. Specify a diameter of 150mm for

pipe 1.012. It is displayed in red to show it is user specified.

If the Design Flow (l/s) column is not present it can be turned on by

selecting Preferences from the Network Details toolbar.

If APT is not present, cover levels can be entered on the Network Details

spreadsheet or on the Manhole Properties form.

Click the Plan button to return to the graphical view.

Plan

Reopen the toolbox and select Define Ancillaries Annotation.

Define Ancillaries Annotation

Select Manhole S13 with the bullseye and a box will appear with the Design

Flow information.




Choose the Select button from the toolbox. Right click on the Design Flow

box and select Properties and untick the Locked option and close the

Properties window. You may now drag the Design Flow box to a more

suitable location.

Multiple Networks

Multiple networks can be designed in DrawNet. To add an additional

network to the drawing click the Network Manager button.

Network Manager

The Network Manager form allows additional Storm, Foul and Existing

networks to be added to the drawing. Click the New Network drop down

arrow and select New Foul - Main Network to add a foul network. The

Design Criteria will appear for Foul - Main.

New Network




Enter the data as shown and click OK .

Right click anywhere on the plan and select the Band Zoom option. Band a

window around the top end of the site as shown and turn off the DXF Snap

option.

Open the Toolbox by clicking the Toolbox button and select the DefineStraight Pipes option.




Draw the Foul network freehand outside the verge line and right click at the

end to finish. The main line of the Foul network will be designed.

Add a branch line to the foul network crossing the road.

DrawNet will identify any crossings that occur between networks. Select




Crossings and Conflicts from the Site menu and a red circle denotes pipe

crossings along with the Crossings / Clashes form, giving pipe and level

information.

Open the 3D World View to see the crossings visually.

Landscape Features

Close the 3D to return to the drawing and turn the DXF Snap back on. Select

the Define Landscape Features button on the Toolbox, which allows houses

and other elements to be added to the drawing. Set the Quick Data value to

7.5. This will be applied to the height of each house as it is defined.




The house locations are already on the drawing. To define a house click on 3

of the corner points. The house will be drawn over the original layout on the

drawing.

Note: Landscaping Features are only available if APT present. Add the three other houses to the drawing in the same way and open the 3D

World View to see the houses in 3D.

Modifying the Drawing

Additional manholes can be inserted anywhere in the network. Close the 3D

view to return to the drawing and click the Extents button.

Select the Insert Manhole option on the Toolbox.

Insert Manhole

Move the bullseye to midway along pipe S2.002 and left click with the

mouse.




An additional manhole will be added and the network renumbersautomatically.

Open the Display Settings form by clicking the button on the toolbar.

Display Settings

The Display Settings allows each layer to be locked (to stop selection or

inadvertent modification) or the default drawing colour to be specified. All applies the selected colour to all existing layer entities and Del deletes the

layer. Change the Annotation colour to red (so it is visible on print outs).

Set up the Display Settings as shown below to allow selection and movement

of the outfall manhole (see Outfall below).




The outfall manhole can now be moved to any position on the drawing. Click

the Select button on the Toolbox and position the cross hair over the outfall

manhole and Left click. Drag the manhole to a new position on the drawing.

Before continuing move the outfall manhole back to its correct position.

Close the Display Settings form and click the Annotation Settings button.

Annotation Settings

By default the drawing displays Pipe Numbers and Manhole Numbers only.

Additional data can be added to the drawing by modifying the AnnotationSettings.




Right clicking anywhere on the drawing displays a pop-up menu, which

allows any of the forms to be opened instead of selecting them from the

toolbar.

There is also the Pan option, which allows panning by clicking the central

scroll button on your mouse and zooming by scrolling the button.




A second terrain model The preliminary design for the Road drainage is now complete.

True ground levels for the road and verges are available in a digital terrainmodel which can be imported over the top of the original DXF file. To do

this select GIS Data from the Site menu.

Note: Importing a Terrain model is only available if APT present.

On the GIS Data form select the Surfaces Tab and then Proposed from the

drop down. Select the Import button from the toolbar. At the Open File

prompt change the file type to .pwf , select the Example13.pwf file and say

Yes to the warnings. Select OK to the GIS data form and say Yes to the

warning.

The new digital terrain data will be loaded, replacing the existing

information. The longsection automatically updates to show the new ground /

road levels and the system is automatically optimised.

View the 3D (making sure the Show TIN Ground option is turned on under

the Model tab) to see the site with the true levels. Again you can switch

between existing and proposed ground levels using the dropdown.




Plotting

Close the 3D and click the Print Preview button.

Print Preview

Turn off the TIN and GIS Ground from under the View Options dropdown

toolbar.

From the File menu select Page Setup, change the Orientation to Landscape

and click OK . From the View Options menu make sure Graphics is turned

on.

Right click on the drawing and select Set Print Scale.

Enter a Print Scale (1:X) of 1500 and select OK . Close the properties form

and right click on the drawing and select Pan. A Hand will appear allowing

the drawing to be dragged into the centre of the print preview.

To use standard SFA5 colours and line styles select the SFA option from the

Pipe Colours and Manhole Colours dropdown.




Clicking the Plot Image button will send the final layout to a printer or

plotter.

Plot Image

The final drawing may be output and merged with the original DXF drawing

for export to CAD facilities by clicking the Save DXF button.

Save DXF

This provides a seamless integration with CAD systems.

All items that have a level associated with them will have this represented as

an elevation(s) associated with the 2D entity. i.e. Invert Levels on Manholes

and US and DS IL for Pipes. Levels will also be appended to TIN Data and

FloodFlow results if present.




and US and DS IL for Pipes. Levels will also be appended to TIN Data and

FloodFlow results if present.

To assist with Building Information Modelling (BIM) a switch is in place that

allows 3D Network entities to be exported with the DrawNet module. Whenthis option is selected the following will occur:

• Pipes - Exported as Cylinder for standard pipe based on diameter oras a series of faces to represent Conduits and Section Types

• Manholes - Exported as a Cylinder for circular manholes or a Box forSquare manholes, both based on dimension and drawn from Cover

Level down to manhole base.





Example 14 – FloodFlowOverland Flow Path Analysis




IntroductionThe terms “Exceedence” and “Risk” have become more common in

engineering specifications in recent years. While engineers have been

concentrating on the underground (minor) system for many years, we mustalso assess the performance of the above ground (major) system. The major

system can take many forms, including the careful design of landscaping to

ensure that the risks to property and life are reduced.

FloodFlow is a 2D analysis engine that can generate overland flood flow

paths. When used in conjunction with Simulation APT it provides minute-

by-minute flood depths, directions and velocities. This allows a full

assessment of the risk associated with the flooding generated during extreme

events. Dynamic FloodFlow Analysis can link the major and minor systems

together in one analysis run, providing fully integrated 1D and 2D analysis

for the first time.

When used with DrawNet APT the FloodFlow methods provide a powerful

design aid. The geometric analysis tools allow sink points and ridgelines to

be identified on the ground surface at the click of a button. This makes

planning the location of terminal gullies and overland flow corridors a simple

task. A FloodFlow analysis can also be carried out using a constant waterdepth across the entire site. The main overland flow routes can then be

identified at the very start of the design process.

Using Simulation and FloodFlow Analysis engines, it is possible to apply

rainfall directly to the terrain model removing the need to identify catchment

areas for specific manholes as the rainfall will find its own way into the 1D

model. In combination with DrawNet the terrain model can be zoned, with

each zone allowing rural and urban areas to be distinguished, each with itsown runoff coefficient.

The following example takes the design from Example 13 and demonstrates

the use of FloodFlow to identify the risks associated with overland flows.




FloodFlow within DrawNet APTOpen Network using your preferred method. At the Open screen select Open

Existing File. Locate the .mdx file saved at the end of Example 13.

Alternatively, load Example14.mdx from the \Micro Drainage 2014\Datadirectory.

This should then automatically present you with the Plan. Select the Proposed

view using the drop down in the bottom left hand corner.

The ability to perform a FloodFlow analysis at an early design stage helps to

prevent the need for major modifications to the drainage network and/or

landscaping at a later time.

We can now run FloodFlow to identify sink points, ridgelines and likely

overland flow routes.

Right click on the Drawing background and select Band Zoom. Left Click

and Drag a box around the houses and cul-de-sac at the southern end of the

site.

Click on the View Options drop down menu and click the TIN Analysis icon.

View Options TIN Analysis

Each triangle in the DTM will now display an arrow, or red cross, to show

the direction of steepest ground slope. These arrows are colour coded to

represent the gradient. The display settings gives a key of the colours and

symbols used.




Ridgelines are identified where the surrounding triangles are sloping away

from the line. These are marked with a thick black and white line, and can be

seen along the centre line of the road, as well as along the kerb lines.

A sink point is identified where a vertex is lower than all of the surroundingvertices. Sink points are marked on the drawing by a black cross inside a

solid red circle. The engineer would need to ensure that additional gullies are

considered for these locations, to prevent ponding of surface water.

The TIN Analysis can also be viewed in 3D; the same arrows and symbols

are overlaid on the terrain surface.




Click the 3D World View icon and turn on the TIN Analysis from the View

Options menu.

Close the 3D World View to return to the drawing. Open the View Options

menu and turn off the TIN Analysis. A full FloodFlow analysis can becarried out in DrawNet by applying a starting water depth to the whole

drawing.

Click the FloodFlow Analysis icon on the lower toolbar and the FloodFlow

Analysis Options are displayed. Set the Grid Size to 2m, the water depth to

50 mm and the analysis time to 60 minutes and click OK to accept the rest of

the default values. This will apply 50 mm of rainfall across the entire TIN

and allow it to flow for 60 minutes.

FloodFlow Analysis

Note: In DrawNet the FloodFlow analysis is only performed on the section

of the Drawing that is currently displayed.

DrawNet now displays the peak flood depths and Velocity-Depths for each

grid square. The colour coding is the same as FloodFlow in Simulation. The

results are used to validate the TIN Analysis.




To view the results of the FloodFlow analysis, turn on FloodFlow Depth and

FloodFlow Velocity from the View Options menu.

FloodFlow Depth FloodFlow Velocity

To user define the graphical results open the Display Settings and select

FloodFlow Colours.

Display Settings

By default squares are transparent until the water is 10mm deep. 10 to

100mm is coloured blue. 100mm to 300mm is coloured red. 300mm to

600mm is coloured yellow. Above 600mm the squares are white.

Each of the colours becomes lighter as the depth approaches the upper end of

the range. Click on any colour and the Colour Picker is displayed.

Each square in the terrain grid containing more than the minimum depth of

water displays an arrow showing the direction of flow. The arrow is coloured

depending on the product of velocity and depth. By default 0-0.1 (m2/s) is

blue. 0.1-0.2 is red and 0.2 to 0.3 is gold. Above 0.3 the arrow is grey.

Again each of these can be edited.

The exact values of the Flood Depth and the Velocity-Depth are shown at the

bottom right of the Plan. Hover the cursor over a flooded grid square to view

these values.




Select the FloodFlow Settings tab.

Semi-transparent depth on Plan enables an aerial photograph or other

background image to be seen behind the FloodFlow depth squares. As we

will not be using a background image deselect the option.

We will leave Show continuous surface ticked on. This will apply the grid

level at the centre of each grid square and the level linearly interpolated in

between rather than show each square individually. If working with a model

with sharp details (i.e. break lines) you may want to deselect this option.

You can also specify maximum number of grid squares that will be displayed

along either of the axis for the Plan/3D Level of Detail (LOD). The valueshould be set to gives a suitable performance level on your PC.

Close the Display Settings and view the Plan, the outline of the maximum

flood levels is displayed.




FloodFlow within Simulation APTA 100 year 15 minute winter storm has been chosen, with 30% Additional

Flow for climate change. Set the Simulation Criteria as shown.

Note: To identify the storms that produce flooding, the Seasonal Return

Period Wizard should be run. Please see Example 8 for details.

Click OK to the Simulation Criteria and run the analysis by clicking the Go

button.

Run Analysis

The Summary of Results show that this event causes flooding at four nodes

in the network. FloodFlow can now be used to identify the flow pathways

that this flooding will follow.

Click on the Analyse menu and select the FloodFlow Analysis option.




The FloodFlow Analysis Options are displayed.

The Analysis Method can be set to either Explicit or ADI (AlternateDirection Implicit). For this example we will leave it set to ADI and we will

leave the Analysis Speed set to Medium. For more information on Analysis

Methods, click on the Help button.

The Grid Size defaults to 4m. In this case we are looking at flooding on a

road that is around 5.5m wide. Change the Grid Size to 2m and set the

Surface as Urban.




There are three FloodFlow Analysis Type choices that can be selected from

the dropdown option. The first, FloodFlow Static Analysis, uses the results

of our Simulation analysis to generate the overland flow routes. This method

retains all floodwater above ground.

The second method, FloodFlow Dynamic Analysis, links the minor and

major systems, allowing floodwater to re-enter the underground drainage

network if spare capacity is available. In this case our pipe network is below

a road, so it is likely that flood water will be able to re-enter the network.

The third method, Apply Rainfall, applies the rainfall directly to the terrain

model. The water is then free to find its own way into the underground

drainage network. Cv values can be defined for different surface zones. Thismethod will eliminate the need to specify catchment areas for each manhole.

Select Dynamic Analysis and leave the 1D Timestep as Fine and click OK to

start the analysis.

Once the analysis has finished click Save and the Summary of Results is

displayed.

The Summary shows that additional pipes are now showing a Flood warning.

This is because the Dynamic Analysis has fed some of the floodwater back

into the underground system, causing additional flooding downstream.

Click on the Plan icon to view this graphically.

Plan

The Plan shows the triangulated Digital Terrain Model and the locations of

the houses added in DrawNet. If these are not shown, ensure that the TIN

and GIS Features options are turned on under the View Options menu.




To view the results of the FloodFlow analysis, turn on FloodFlow Depth and

FloodFlow Velocity from the View Options menu.

Zoom in on the housing area to see the impact of the flooding.

To view minute-by-minute flood levels, click on the Play button on the Video

Controller .




In this example it can be seen that all depths are less than 300 mm and that

the Velocity Depth vector never exceeds 0.1 m2/s. However, the proximity

of the flooding to one of the houses may be a problem; we should look at

altering the site layout or levels to mitigate this risk.

The nature of the risk is more apparent when viewed in 3D. Click on the 3D

World View icon and select the Play button to animate the flooding.

Apply RainfallFloodFlow allows the engineers to escape the confines of defining areas for

each manhole node. Instead you can apply rainfall directly to terrain model

and allow it to find its own way into the 1D model (all contributing areas are

ignored). The DTM can be zoned to apply specific runoff (CV) rates fordifferent surface types. Furthermore, areas that fall outside of the site you are

interested in analysing can be excluded to increase analysis speed.

To zone your site, select the plan view and open the Toolbox from the

toolbar.

Toolbox




Select the Misc. tab and click at the FloodFlow Zone button (only available

with the DrawNet module).

FloodFlow Zone

The hand and cross hair will appear. Trace freehand around the impermeable

area by left clicking with the mouse at each point.

Click the Select button on the Toolbox and left click on the area so it turns

red. Then Right click on the area and choose Properties.

The Properties form allows you to select Surface Type, set it to Urban.

Note: FloodFlow modelling using the Apply Rainfall Analysis type

requires the DrawNet module to zone your site.

Click the FloodFlow Exclude Zone button.

FloodFlow Exclude

Exclude the section of the site that has no affect on the housing and roads by

drawing around it using the same method as before. No runoff will contribute

from the excluded zone.




Select FloodFlow Analysis from the Analyse menu.

Set the Analysis Type as Apply Rainfall and all the other variables as shown

above. Here note that the Cv value used is a combination of the Volumetric

Runoff Coefficient and the percentage impervious for the zoned area. Make

sure Apply Exclusions option is selected and click OK to run the analysis.

The results further corroborate the initial TIN Analysis by identifying the

same sink points and ridgelines.




Open the Display Settings and select FloodFlow Colours.

Set the first depth increment to 20. Water depths less then 20mm will now

not be drawn.

To further aid detailed result analysis and visualisation process. It is possible

to generate a cross-section of the result through drawing a polyline for

analysing specific flooding locations. Select the FloodFlow Profile option

from the Toolbox.




FloodFlow Profile

More detail is required on the road outside the houses. Left click with the

mouse to drag the polyline across the road, then left click again and then

immediately right click to display the result.

The results are can been seen as both graphical and tabular. This allows the

engineer to closely inspect specific hazardous locations in you flooded area.

Click the 3D World View icon and use the Compass to view the results in the

3D View.





Example 15 – PluviusUse of Extended Time Series Rainfall




IntroductionPluvius is a complete suite of rainfall data management and analysis

resources, designed to overcome the difficulties previously associated with

obtaining and using extended rainfall records.

The first challenge is the question of access to good quality data. Hourly and

sub-hourly records represent the most important data for pluvial flooding

(flooding caused by rainfall) in urban areas. Pluvius uses the Met Office

DELUGE® database, containing over 700 years worth of rainfall data,

recorded at five-minute intervals on 73 sites across the UK. The data was

obtained from a single source, the Met Office, using tilting bucket rain

gauges and quality controlled against nearby daily check gauges.

In addition to the Met Office's quality controlled data, the Pluvius toolkit

includes the facility for the user to augment this data with their own rain

gauge records.

Secondly, there is the difficulty of data handling. Pluvius is a state of the art

database capable of accessing and analysing huge records very quickly.

It can also be difficult to make sense of so much information. Pluviusincorporates a wide range of analytical and sorting tools to help extract the

important data and to validate it. Engineers can therefore pool long rainfall

records spanning hundreds of years at any location in the UK. All the events

from that record can be extracted, allowing the engineer to identify the most

important of them from a drainage perspective, and generate typical years or

typical seasons from the record.

While there are many potential applications for the data generated by Pluvius,the following example illustrates how this data may be applied to a typical

urban drainage scenario.




The Design ProblemThe site being analysed is close to the confluence of a river and its tributary.

A 3D representation of this is shown below.

The pipe network has been sized and tested using design storms. However,

the system performance must be assessed against a 30 year return period

event. Due to the nature of the site, the event return period is not dependent

upon the rainfall return period alone. Antecedent (ground) wetness and the

water level in the river will also have a large effect. A conservative

assumption of a high water level in the river, and a high runoff percentage,

may provide a solution to this problem. However, this approach is likely to

lead to an over engineered and costly solution, with a very low joint

probability.

To generate the true 30 year return period with confidence, we require up to

300 years of extended time series rainfall, centred on our site location (the

record should be 5 to 10 times the desired return period). We also require

this data to be at a short enough time step to be applicable to the urban

environment.

This example demonstrates how the statistical techniques employed within

Pluvius can be used to generate these records, and how this data can then beused to assess the performance of a drainage system.




Loading PluviusOpen Pluvius using your preferred method. Once Pluvius has loaded, the

Welcome screen is presented.

Moving the mouse cursor over each icon displays a description of the

options. Click the Gauge Manager (top) icon. Here you will find details of

all 73 gauges contained within Pluvius' default database. The Gauge

Manager also allows the addition of extra gauges and rainfall data. For more

information on the Gauge Manager, please see the Rainfall Database section

of MDHelp.

Close the Gauge Manager and proceed to select the Generate Localised

Rainfall (lower) option from the Welcome screen.




Generate Localised RainfallThe Generate Localised Rainfall Wizard is a six step wizard allowing the

user to tailor the outputs from Pluvius to meet their own demands.

To test our drainage system in this case, we require an extended rainfall

record for our site, along with the most severe rainfall events from the record.

The following steps demonstrate how the outputs from Pluvius can be

tailored to each individual situation.

Step 1: New or ExistingAt Step 1 ensure that Create New Analysis is selected, and click the Next

button.

Next

Step 2: Select LocationAt Step 2, we must locate our site. Type Newbury into the Name cell, and

click on the Map button. A map of the UK is presented. Use the box in the

top left to locate the South of England and then click a location to the south

of Newbury on the main map. Values similar to those shown below are

loaded. These values can be over-ruled by typing them in manually if

required. Click Next.




Step 3: Confirm GaugesStep 3 shows the names and locations of the gauges that will be pooled to

generate the extended record.

Gauges can be selected in batches by using the options at the top of the

screen. It is possible to select gauges by the range of their M5-60 values,

their distance from the target site, their Average Annual Rainfall or by

Meteorological Region. In this case, we will select all gauges within the

South East region. Select the Regions check box and choose SE from the

options. Then click the Select button.

26 gauges are now selected, providing a total record length of 274 years.

Scroll through the list to view the full range of gauges selected. Click Next.




Step 4: Start Conditions & Event Settings Run on Time (mins) / Threshold (mm) – During the analysis, Pluvius splits

the record into individual events. Each urban drainage network or catchment

responds differently to rainfall, so the definition of an event can also change.

Pluvius uses the Run on Time and Threshold to define these events in the

following way:

1. From the start of the file, find the first rainfall value that is greater than

the threshold. This is the start time of Event 1.

2. Step through the profile until the rainfall intensity again falls below the

threshold.

3. Step through the next X points in the graph, where X is the Run-On Time.

If any of these points are greater than the threshold, return to step 2 andcontinue from this point. If all values lie below the threshold, the end of

the Event has been found. Return to step 1 and start the process again

from this point.

Accept the default values of 360 minutes (6 hours) and 3 mm.

Timestep (mins) – The event files are saved using the time step set here.

Accept the default of 5 minutes (5 minutes is the interval used by the MetOffice data; a shorter interval does not improve accuracy).

Main Events per year / Superstorm Length (days) – A full explanation of

Superstorms is provided later on in this example. Superstorms are generated

for 0, 1, 2, etc. failures until the number of main events specified has been

produced. The duration of the superstorms is set to the Superstorm Length.

Set Pluvius to generate 2 Main Events per year and accept the default

Superstorm Length of 1 day (the number of ‘main events’ generated will bethe record length x main events per year: 274 x 2 = 548).

Runoff Conditions – A monthly evaporation rate can be set, as well as a

number of other variables used to calculate NAPI values for use with the

New Runoff Equation. The SMD values allow Pluvius to calculate UCWI

and API30 values for each event. In this case, we are not using the New

Runoff Equation, so we can accept the default values. The program will also

output the initial soil moisture content (Cini) for use with the ReFH rainfall

runoff method.




Start Conditions – Additional Start Conditions can be entered; Pluvius then

recalculates these values for the start of each new event. In this case, we are

not using these settings. Ensure that the Include Start Conditions check box

is left blank.

Check that the values entered are as shown below and click Next.

Step 5: Seasonal RequirementsStep 5 is used to determine the date range analysed by the program. By

default, the analysis is run on the entire record. In some circumstances, it

may be necessary to exclude certain parts of the record. For instance, a CSO

analysis may only require rainfall data for the Summer Bathing Season.

Analysis of a rainwater harvesting system for a school may require analyses

to be run on each individual school term. Selecting the Summer or Custom

options from this list allow these analyses to be carried out. For this design,we require analysis of the whole record. Select Annual from the Entire

Record Analysis list.

Pluvius also generates a typical year from the record analysed; this is

explained later on in the example. A typical year can be generated from

statistical analysis of the entire record, or by generating typical quarter years

and combining them together to produce a full year. In this case, we will run

the analysis using full years. Select Annual from the Annual or QuarterlyTypical Year Analysis list, and click Next.




Step 6: Synthetic Rainfall ParametersThe final step in the wizard allows the user to specify which FSR and/or FEH

design storms are produced. Although these files are not required for use in

Micro Drainage, they may be useful for use with other third party packages.

In Pluvius, the synthetic storms generated can be used to validate the data

exported, and to assign a return period to the superstorms generated. Further

discussion of this is provided later on in this example.

We will compare our data with both FSR and FEH design storms. Select the

FSR check box; the M5-60 and Ratio R are automatically populated. Select

FEH and click the … button. Select the Newbury.csv file from the\Pluvius\Data directory. Now click the Finish icon.

Finish

Pluvius now presents a dialogue box asking for a folder into which the results

will be saved. Select an existing location, or create a new folder, and clickOK to run the analysis.




ResultsOnce the analysis is complete the following results screen is displayed.

The tree diagram on the left hand side provides easy navigation through the

directories produced. Clicking the + buttons expands each directory.

The first directory contains details of the Design Storms produced. Expand

the directory to view the files inside. Selecting a filename displays a graph of

the design storm contained within the file. Close the Design Storms directory

by clicking the - next to it.

Entire RecordExpand the Entire Record directory. This directory is split into four further

sub-directories. Click on All Events and use the Previous and Next buttons

to step through the record one storm at a time. Note that, based on the Event

Settings that we specified, Pluvius has created approximately 20,000

individual events from the 274 year record.




Al l EventsClick the + button to expand the All Events directory. A .red file has been

produced for each of these events. Clicking on the name of a file displays a

graph of the storm event as shown below.

Superstorms"The two most important variables for engineering drainage networks are

intensity and volume."

This is the key to generating meaningful design storms for testing networks.

This idea can be applied to very large data sets, consisting of many individual

rainfall files, to produce a single all-encompassing design storm. The SuperStorm is created by strict observance of the underlying principle stated above

- we must preserve the Peak Intensity as well as the total volume of the

storm. Since these are likely to be different for each rainfall file, the worst

cases will be used. In fact, the superstorm is designed to balance volume not

only across the storm as a whole, but also at every sub-duration within the

storm as well.

The theory behind generating the superstorm is available in the Pluvius Helpfile. There is also a discussion of superstorm theory in the FAQs.




Close the All Events directory and expand the Superstorms directory. Click

on Super0.red to view the graph.

Super0.red has been built to incorporate all of the worst case events in the

entire record. Theoretically, if a drainage network can contain this storm

without flooding, then it should be able to convey the entire 274 year record.

The superstorm is built from the middle outwards. The 5 minutes around the

centre of the storm represents the worst 5 minutes of rainfall within the entire

record. The average intensity of the 10 minutes around the centre represents

the worst 10 minutes of rainfall in the record. This process is continued untilthe entire 24 hour superstorm has been built.

The red and green lines on the graph show the equivalent FSR and FEH

return periods. Note that the return period varies for the different duration

events contained within the superstorm.

Super1.red has been built by discarding the worst case rainfall intensities and

plotting the second worst 5 minutes, second worst 10 minutes, etc. Each

superstorm is referenced by a number in the file name, in this case “1”. This

number represents how many times the events used to build the storm were

exceeded within the 274 year record. This number is commonly referred to

as the failure rate, or the number of failures.

Super9.red represents the storms that were exceeded 9 times within the

record (9 failures). As the entire record is 274 years long, this is the event

that is exceeded, on average, once every 30 years. So Super9.red is

equivalent to a 30 year return period design storm built from the real data.




Click on Super9.red.

The graph shows that the FEH return period is consistently between 20 years

and 40 years. This may appear to be a large range, but it represents only a

15% difference in rainfall intensities. Considering the randomness of real

rainfall data, this is a very good result.

Selecting Super27.red displays a Superstorm equivalent to a 10 year return

period; Super137.red is equivalent to the 2 year return period. It can be seen

that the return period shown becomes more and more consistent as the

number of failures is increased.




Main EventsIn building the superstorms, Pluvius uses data from files in the All Events

directory. Each of the files that contribute to the superstorm are copied into

the Main Events directory, as it is these events that we are most interested in

when analysing our drainage network.

Click on the - button to close the Superstorms directory and then expand the

Main Events. 548 main events have been generated from this record. Select

some of the Main Event files to view their graphs. These are the rainfall

events that we will simulate with our drainage network later on in the

example.




IDF TablesClose the Main Events directory and expand the IDF Tables. Now select 15

Min from the list. The POT Analysis graph for 15 minute events is

displayed.

This graph shows rainfall intensity plotted against return period on a log

scale. The blue dots represent 15 minute rainfall events from the rainfallrecord. The yellow line is a best-fit line drawn through these points. The red

and green lines show the equivalent FSR and FEH rainfall intensities. The

graph allows us to assess the data set. In this case, there is very good

correlation between the plotted rainfall and the FSR line. In the 180 minute

POT Analysis, shown below, the correlation with the FEH line is very good.




Click on Newbury PT1M5.IDF. The 5 year return period IDF curves from

FSR and FEH are plotted over a bar chart, showing the corresponding rainfall

intensities from the rainfall record. The graph shows that there is a very good

correlation between all three data sets for the 5 year return period.

Newbury PT2M2.IDF shows the 2 year return period IDF data.

Typical YearClose the IDF Tables and expand the Typical Year directory. Click on the

Annual icon.

To generate the typical year, Pluvius calculates the number of days within

various categories. Firstly, how many days had more than 10mm of rainfall,

then how many had more than 12mm, and so on. The number in each

category is then averaged across the entire record, so that a mean value is

generated. The year with the lowest standard deviation is assumed to be thetypical year.




In this example, the year 1992 is shown to be typical. This is not the actual

year 1992. When combining gauges to produce the continuous record,

Pluvius needs a starting point to date the files. To ensure the output files are

compatible with external software, the year 1801 has been chosen as the start

date for these files. In this case, our record starts in 1801 and finishes in2074.

The number of dry days in each year is also displayed. Choosing a year with

a high number of dry days may be useful for testing a rainwater harvesting

system.

Expand the Annual directory and the Superstorms directory within it. Click

on Super0.red to view a Superstorm of the typical year. A typical year would

not be expected to contain any extreme rainfall, so we should not expect any

high return periods. All return periods for this Superstorm are around 6 years

or below.

This completes the Pluvius section of the example. We will now take a

selection of the files generated by Pluvius into Simulation APT to test our

drainage network. The tree diagram shown in Pluvius matches the directory

structure output by Pluvius, making it easy to locate the required data.




SimulationOpen Simulation APT using your preferred method. At the Welcome screen,

choose Open Existing File. Select Example15.mdx from the \Pluvius\Data

directory.

Click OK to the Simulation Criteria and click the Plan icon on the main

toolbar to view the network.

Plan

Lines 1, 2 and 3 represent the main river and the tributary. FEH Unit

Hydrographs have been generated at Pipes 1.000 and 3.000 to represent the

flows entering the river and tributary sections. The urban drainage network

enters the river at pipe 4.014.

The network has been analysed with design storms; it passes the 30 year

return period with no on-site flooding. We will now run the main events

through the system.

Rainfall WizardSelect Rainfall Wizard from the Wizards menu. Ensure the Runoff Details

are set as shown below.




Click Next. Click Add to locate the directory that Pluvius has saved the

results to. Double Click on Entire Record, and then on Main Events. This

will display and select all 548 main event files. You will need to change the

file type to .red to load the files.

Click Next and at Step 3 click Finish to start the analysis. Click OK to themessage stating Unit Hydrographs are present and Yes to the message to

extend runtimes.

Once the analysis is complete, the Summary of Results is presented. Click

the Critical Storm button to view the critical event at each node.

Critical Storm

Event number 18,038 is critical for the majority of the river network; event

number 1,475 is critical for most of the drainage network.

Change the Critical Rank No to 9 to view the 30 year return period event.

Note: This is the 30 year event and not the 30 year storm. This takes into

account the combined probabilities of the rainfall event, the ground

wetness, and the water level in the river.




The results show that the drainage network does not flood for this event.

Similarly, the Critical Rank No can be changed to 27 or 137 to view the 10

and 2 year return periods.

The 100 year Return PeriodAs we do not have 500-1000 years of rainfall data, we cannot produce the

100 year return period directly. However, we can still produce an

approximation to the 100 year event by applying a growth curve to our 30

year data.

The FSR and FEH growth curves for our site location show that a 1 day

duration, 100 year return period event is around 30% larger than thecorresponding 30 year event. We may also wish to assess the potential

impacts of climate change. If we assume that rainfall intensities may

increase by 30% due to climate change, then the total required increase is70%.

Super9.red has been shown to correspond to a 30 year return period. Adding

70% to all intensities in this file should approximate to a 100 year event with

an additional 30% for climate change.

Open the Simulation Criteria by clicking the icon, or by selecting Simulation




Criteria from the Site menu. Set the data as shown below, ensuring that an

Additional Flow - % of Total Flow of 70% has been entered.

Change the Rainfall Model to Rainfall Profile and click the Edit button to

open the Rainfall Profile form.

Click the Import icon and locate the Super9.red rainfall file.

Click OK to the Rainfall Profile form, click OK to the Match Rainfall

Profiles to Pipes form after clicking OK to the Simulation Criteria.

Click Go to run the analysis.

The Summary of Results is presented. This shows that the event has caused




flooding in both the river and drainage networks. Scroll through the list of

nodes to see the full extent of the flooding.

To view the impact of this flooding we could run a FloodFlow analysis on the

site. For more information on FloodFlow please see Example 14.

Note: It is possible to run the entire 274 year record if required. This can

be achieved by changing the Rainfall Model to Continuous Analysis in the

Simulation Criteria and then loading all of the event files from the \Entire

Record\All Events directory.




ConclusionThe analysis tools in Pluvius can be used to generate an extended rainfall

record for any location within the UK. In this example, we had the specific

problem of a drainage network discharging to a river. The river levels werefurther complicated by the effect of a tributary. The use of Pluvius alongside

the analysis tools of Simulation has allowed us to assess this combination of

problems simultaneously. By analysing the rainfall record, and identifying

the most critical events for our specific problem, we have been able to take

account of the combined probabilities of the rainfall event, the water level in

the river, and the ground wetness. This allows us the confidence that we

have assessed the true 30 year return period event and not just the 30 year

rainfall. As a final check, we have also been able to demonstrate the

magnitude of flooding that a 100 year event may cause.

The outputs generated by Pluvius are not restricted to analysing urban

drainage networks. In fact, due to the quality of the data, a large range of uses

exist, including:

•

Testing Rainwater Harvesting Systems, using rainfall data generated

for a 'Typical Year'.

• Assessing and improving CSO performance, using data generated for

summer bathing seasons.

•

Validating the performance of design storms for a specific location.

• Continuous Analysis of Sustainable Drainage Systems (SUDS).

•

Assessing the effect of drain down times on a system’s ability tocontain future events.

•

Drainage Area Planning.

•

River Modelling.

• Analysis of joint / combined probabilities.



Appendix



Appendix i Page i.1


Appendix iHydraulic Conduits



Page i.2 Appendix i

IntroductionMicro Drainage is supplied with a library comprising 65 hydraulic conduits

that are embedded within it.

You also have the facility to create your own conduit libraries of up to 999

sections. Micro Drainage enables you to select sections from the internal

library or your own libraries from within appropriate modules.

The standard conduits include box culverts, trapezoidal channels, dual

pipelines, triple pipelines, and egg shaped sewers. In addition, Micro

Drainage allows you to create your own section designs when you are

building a library.

Sections can be chosen in the System 1 module by specifying their conduit

number in lieu of a diameter. Full details of the conduits used in any design

are displayed on the hard copy.

Example 2 in this manual incorporates the practical application of the

resources described here.

Specifying sections within System 1The default hydraulic sections library is automatically loaded every time you

open or create a Storm or Foul network. However, you can have both the

default library and your own hydraulic sections library available

simultaneously. This gives you the choice of specifying sections either from

the default library or your own range, simply by entering the section number.

To do this, simply move the cursor to the pipe diameter field for the pipe you

wish to specify as a conduit. Then click the Conduits button.

Conduits

System 1 presents you with the Conduit Picker , featuring the pre-defined

system conduits under the System tab.



Appendix i Page i.3

Creating your own conduit LibraryTo create your own conduit library, select the User tab from the Conduit

Picker .

Then click the Edit button and you will be presented with the Conduit

Designer spreadsheet.



Page i.4 Appendix i

Entering dataProceed to enter the data set out below, which includes examples of each

kind of section. Start by entering the values shown for the height and

connection height, beginning with 600mm for Section 1.

Micro Drainage gives you a variety of standard shapes to specify for your

section. The toolbar at the left of the spreadsheet provides you with a graphic

representation of the shapes.



Appendix i Page i.5

Click on each of the labels in turn to see the shapes available.

Then, to apply a rectangular shape with no splay, highlight and

specify the relevant section under Capped and simply click onthe shape button.

The symbol representing the shape you have chosen will appear in the

symbol field of the spreadsheet.

Follow the same process for each different section, observing the points at

which data in addition to the height and connection height are required. Youwill note, for instance, that the quadruple pipe section and the egg-shaped

section require no other data to be entered.

Micro Drainage will also make the calculations required by the analysis

modules - such as System 1 or Simulation - for which this library may be

required. Full bore capacities, velocities, volumes and proportional velocities,

capacities and volumes can also be calculated (see below and Example 2).

The physical dimensions entered here must also include connection pointsand enough detail for the Simulation module to analyse backwater and

routing though the conduits.

When you have entered all the necessary data the Export button allows you to

save the library so it can be opened for another project.

Save the library as Sample, as shown here.



Page i.6 Appendix i

Similarly the Import button can be used to load existing .sec or .secx files.

Simply click OK to the Conduit Designer and the Conduit Picker window

will now display the User conduits.

The Conduit Picker window will automatically calculate the flow capacity for

your chosen section, using the data from the project on which you are

currently working. Thus you can check that the section has sufficient capacity before introducing it into the network.

Note: When creating your own .secx file, you may choose to group similar

sections together, leaving gaps in the spreadsheet. However, when Conduit

Picker loads your library it will omit any gaps. Nevertheless, the section

numbers will remain the same.



Appendix i Page i.7

Entering individual sections To specify a particular section, you can simply enter the section number in

the Pipe Diameter field of the network spreadsheet. Micro Drainage will not

accept pipe diameters of 65mm or less, so any figure you enter between 1 and

65 will automatically be interpreted as a section from the conduit library.

However, your own library will hold up to 999 sections. To avoid confusion,

with either the conduit library or with a pipe diameter value, you should enter

the section number followed by a minus sign. This instructs the module you

are working in to take the appropriate section from your own library. The

number is shown with the minus sign in the Network Details spreadsheet.

You can also enter sections by highlighting the Pipe Diameter field of your

chosen pipe and clicking the Conduits button. When the Conduit Picker

appears, select the System or User tab and highlight the section you require

and click OK . The section will be entered with the section number shown in

place of a pipe diameter; again, the number will be shown as a negative if

you have chosen a section from the User tab.

A full list of the default conduit library supplied is given later in this

appendix. Descriptive details for the hard copy are also available.



Page i.8 Appendix i

Defining your own sectionsYou may need to specify a section, which does not conform to the standard

dimensions and patterns supplied. Micro Drainage gives you the resources to

do so.

Begin by highlighting the section number you require for your design. From

the conduit spreadsheet, choose Create from the toolbar of shape options.

Then click Define.

As an example, we will design a benched trapezoidal section.

Enter the coordinates shown in the usual way. Note how the section shape

appears as each line is drawn.



Appendix i Page i.9

Note also that the dimensions are entered to the nearest millimetre.

Succeeding values cannot be identical for the X (m) coordinates; hence the

need to enter 0.999 and 1.000 for rows 7 and 8 in the Base spreadsheet, even

though it is intended that this side wall should be precisely vertical. For a real

project, you will probably find it helpful to draw a sketch of your section firstand define the coordinates for each point.

With your drawing complete, simply click OK and the section is entered in

the field selected.



Page i.10 Appendix i

Rectangular sections - standard culverts

Section b h 4*m Corner A

No. (m) (m) (m) Splay (m2)

1 1200 600 0.833 125x125 0.692 1500 600 0.891 125x125 0.873 1800 600 0.928 175x175 1.02

4 1200 800 1.002 125x125 0.93

5 1500 800 1.086 125x125 1.17

6 1800 800 1.152 175x175 1.387 2100 800 1.201 175x175 1.62

8 1200 1000 1.139 125x125 1.179 1500 1000 1.248 125x125 1.47

10 1800 1000 1.340 175x175 1.74

11 2100 1000 1.409 175x175 2.0412 2400 1000 1.464 175x175 2.34

13 1800 1200 1.502 175x175 2.10

14 2100 1200 1.589 175x175 2.4615 2400 1200 1.661 175x175 2.82

16 2700 1200 1.726 225x225 3.1417 1800 1500 1.705 175x175 2.64

18 2100 1500 1.820 175x175 3.0919 2400 1500 1.916 175x175 3.5420 2700 1500 2.006 225x225 3.95

21 2100 1800 2.013 175x175 3.72

22 2400 1800 2.132 175x175 4.2623 2700 1800 2.247 225x225 4.7624 3000 1800 2.336 225x225 5.30

25 3000 2100 2.563 225x225 6.20

m = hydraulic radius; b = width of culvert section; h = height of culvert section



Appendix i Page i.11

Trapezoidal sections

A=bh+h2 For maximum efficiency b=0.8284h

Section b h m 4*m A No. (m) (m) (m) (m) (m2)

26 0.300 0.362 0.181 0.725 0.240

27 0.375 0.453 0.2265 0.906 0.37528 0.450 0.543 0.2715 1.086 0.539

29 0.600 0.724 0.362 1.449 0.95930 0.800 0.966 0.483 1.932 1.70631 1.000 1.207 0.6035 2.414 2.664

A=bh+1.5h2 For maximum efficiency b=0.6056h

Section b h m 4*m A No (m) (m) (m) (m) (m2)

32 0.300 0.495 0.2475 0.989 0.51233 0.375 0.619 0.3095 1.236 0.800

34 0.450 0.743 0.3715 1.484 1.153

35 0.600 0.991 0.4955 1.980 2.05136 0.800 1.321 0.6605 2.638 3.644




Trapezoidal sections - continued

A=bh+2h2 For maximum efficiency b+0.472h

Section b h m 4*m A No (m) (m) (m) (m) (m2)

37 0.300 0.636 0.318 1.270 0.985

38 0.375 0.794 0.387 1.585 1.53539 0.450 0.953 0.4765 1.903 2.21140 0.600 1.271 0.6355 2.538 3.933



Appendix i Page i.13

Dual Pipelines

Section diameter 4*m Area No (mm) (mm) (m2)

41 2 x 300 299 0.141

42 2x 375 375 0.221

43 2 x 450 450 0.31844 2 x 525 525 0.43345 2 x 600 599 0.565

Triple Pipelines

Section diameter 4*m Area No. (mm) (mm) (m2)

46 3 x 375 375 0.331

47 3 x 450 450 0.47748 3 x 525 525 0.64949 3 x 600 600 0.848

50 3 x 675 675 1.074

m=hydraulic radius




Egg Shaped Pipes

A=H*H/1.96 B=.667*H 4*m+.7721*H

Section H B 4*m A No. (m) (m) (m) (m2)

51 .533 .356 .412 .14552 .61 .406 .471 .190

53 .686 .457 .529 .240

54 .762 .508 .588 .296

55 .838 .559 .646 .35856 .914 .61 .705 .426

57 .991 .66 .765 .501

58 1.067 .711 .824 .58159 1.143 .762 .883 .667

60 1.219 .813 .941 .75861 1.372 .914 1.058 .960

62 1.524 1.016 1.176 1.18563 1.676 1.118 1.294 1.43364 1.829 1.219 1.412 1.707

65 2.137 1.422 1.650 2.330



Appendix ii Page ii.1


Appendix iiIDF, CRP and Hyetograph



Page ii.2 Appendix ii

IDFThe Rational Method (and its variants) bases its calculations on rainfall data

in the form of Intensity, Duration and Frequency (IDF) data.

IDF libraries are created on the principle that for a given return period (or

frequency) and a set duration, a storm will have a known average intensity.

For example, a storm near Seattle in the USA with a return period of five

years (the frequency) and a duration of 20 minutes, has an average intensity

of 17.5 mm/hr.

The IDF library represents a single frequency and is a sequential list of

average intensities for different durations of storm. In the Rational Method,

each pipe is designed for the average intensity of a storm of a duration equal

to its time of concentration. It could be said, therefore, that each pipe or

channel in a network is designed for a different storm, as each pipe has a

unique time of concentration.

The Rational Method is therefore not suitable for backwater analysis, or any

analysis that involves the effect of one continuous storm, as no two pipes are

designed using the same storm. A Simulation program should be used to

determine the real hydraulic grade lines, which will vary minute by minutethroughout a storm.

Entering IDF dataFrom within the System 1 module, select Design Criteria from the Network

menu. You will see the option IDF Library listed:

Select this option and click the Load button.

Load




The IDF library spreadsheet appears:

Enter the data in the usual way. Where a value is repeated, for instance

towards the end of the storm, simply highlight the value and click Repeat; the

value will automatically be entered into all remaining cells on the

spreadsheet.

Note: Storms of 1, 2 or 5 minute increments (100 entries) are usually used

with Rational Methods, while the IDF series provides sufficient durations

for hydrograph methods.

If you wish to save the IDF library for use with another file, click the Export

icon and you are invited to save the file. Enter a suitable name and the file

can be saved with the extension .idfx or .idf.

Click the Import icon and the Open IDF File window appears which allows

you to load .idfx or .idf files.




The example here shows some of the .idfx files supplied as standard with

your Micro Drainage software. Where you have created your own .idfx file,

the name will be shown and you can open it in the usual way.

Click Cancel and when you have entered the data on the previous page, click

OK to use the IDF library with the current design.

The CRP and the hyetographTo verify the real hydraulic performance of any system during a rainfall

event, a hydrograph method (including Simulation and Source Control) need

more information than the average intensity of a storm and the IDF library isgenerally not sufficient for this purpose.

However, if IDF information is all you have, then Micro Drainage provides a

method for producing a storm profile based on this information.

With a Hydrograph method, individual storms are run from start to finish.

The Seattle storm of 17.5 mm/hr average intensity is very unlikely to rain at

exactly 17.5 mm/hr for the whole of the 20 minutes. Most precipitation starts

slowly, peaks near the mid-point of its duration and tails off again. It would




not be unusual for a storm to have a peak intensity 4 times the average

intensity.

To get a realistic result from a Hydrograph method it is necessary to add a

shape, or profile, to the storm which is characteristic of the geographicallocation. These shapes are usually expressed as a Cumulative Rainfall Profile

(CRP). If you combine an average intensity read from IDF data with a CRP,

the result is a storm profile (hyetograph) which shows the variation of rainfall

throughout the whole storm.

Generating a rainfall profileIf you have good IDF and CRP data then you can fully utilise the

sophisticated hydrograph methods contained in Micro Drainage. In the UK,

for example, all this data exists and is built into the software. But while CRP

data is not always available elsewhere, it is still possible to obtain a profile

from IDF data for engineering purposes.

The two most important variables for engineering drainage networks are

intensity and volume.

For Source Control, the most important data is contained in the IDF library,which is usually widely available. The volume of a storm does not vary with

the CRP profile. The engineer knows the average intensity from the IDF data

and he therefore knows the volume of the storm.

The Simulation program needs good volume data and good peak precipitation

data. Pipe flow, and hence local flooding, is greatly affected by peak

discharge, so it is necessary to know both the volume of a storm (average

intensity) and the peak intensity.

Peak practiceA clue to the peak intensity of a long storm can be found in the average

intensity of a short duration storm of the same frequency and location. So if a

100 minute storm in Seattle has an average intensity of 7.5 mm/hr, and a 10

minute storm in the same location has an average intensity of 30 mm/hr, it

would not be unreasonable to construct a rainfall profile that lasts for 100

minutes, has a peak intensity of 30 mm/hr and an average intensity of 7.5mm/hr.




This profile combines the peak intensity of a short duration storm and the

volume of the longer storm. It will therefore provide a satisfactory engineered

profile for design.

Note: CRP data is available in the USA for SCS methods, so the engineer

has a choice.

Brewing up a stormMicro Drainage can generate several typical storms from IDF data. In

practice, however, a 2 hour storm that has a peak similar to a 5 minute

duration storm, and a 24 hour storm that peaks similar to the average 30

minute intensity are sufficient to cover a whole spectrum of characteristics.

These two storms provide both ends of the spectrum - a long storm which

delivers a large volume and a shorter storm that has a significant peak

rainfall. A design that satisfies both these criteria in the Source Control or

Simulation programs will be a satisfactory design.

The profiles produced by Micro Drainage from IDF data use several storms

to produce the hyetograph. The 2 hour storm uses the intensities of the 120,60, 30, 15 and 5 minute durations to construct a profile, so that the average

intensity measured each side of the centre of the storm equates to the average

intensities for these durations. This single 2 hour storm combines the effects

of storms of 5 different durations. The 24 hour storm combines the intensities

of the 24, 12, 6, 2, 1 and half-hour durations.

In rare cases a storm longer than one day will be critical for the calculation of

storage volume. In particular, when the allowable discharge from the networkis very low, a storm of low average intensity may still cause the system to fill

to the point of flooding.

Such storms are usually only critical when a storage structure has been

designed to restrict the flow to very low levels. Running these longer storms

at their average intensity throughout will demonstrate whether or not the

system can accommodate the accumulated volume.Micro Drainage incorporates the facility to create your own IDF and Rainfall

Files. You can therefore model storms on the basis of any global rainfall




pattern. Profiles can be built either by applying an appropriate cumulative

profile to a your own custom-made IDF File, generating a file from IDF data

alone - using the Micro Drainage Rainfall Generator - or by keying data

directly into a Rainfall Profile spreadsheet to create a hyetograph.

CRP and HyetographYou also have the facility to enter cumulative rainfall profile (CRP) data,

which can be combined with IDF data to create a Hyetograph.

IDF data onlyTo generate a file from IDF data, select the Rainfall Profile option from the

Simulation Criteria form in Simulation or from Global Variables Inflowoptions in Source Control.

Click the Edit button to open the Rainfall Profile form.

Now select the Generate Profile data button to open the Generate Rainfall

form.




Generate Profile data

The unique Generate Rainfall form appears:

Ensure the IDF/CRP Data tab is selected, click the Edit button next to the

IDF File graph and open the Trump25.idfx file. Select a duration of 120

minutes for the storm, then hit Generate.

The Rainfall Generator creates a curve for the storm:

Save the file as Trump25a.redx by clicking the Export button.

Now select 1440 minutes as the storm duration and hit Generate again. Save

this new curve as Trump25b.redx.




You now have hyetographs for a 2 hour and a 24 hour storm which can be

used for analysis.

Combining IDF and CRP dataIf you have CRP data as well as IDF data, you can use the rainfall generator

to combine them in a curve. Re-open the Generate Rainfall form and open

Trump25.idfx as before.

Before you hit Generate, however, click on the Edit button next to the CRP

File graph box. Select UK50.crpx and the file and its key data appear within

the generator. Select a 2 hour storm. Now select Generate and the curve is

created.

Notice that the figure for the average intensity has been re-calculated to take

account of the IDF data.

In addition, if you have rainfall profile data, you can create a hyetograph

immediately, using the Rainfall Profile form. Use the same procedure as you

used for the IDF spreadsheet both to open, save and to enter data into the

CRP and rainfall profile spreadsheets.



Appendix iii Page iii.1


Appendix iiiRural Discharge



Page iii.2 Appendix iii

HydrologyTechniques for the derivation of Peak Flows from undeveloped and

partly urbanised catchments, also used for the determination of

allowable discharge from new developments.

The methods for determining runoff from ungauged catchments have been

improved since the first publication of the Flood Studies Report. However

they are strewn over many years and several references. The following is a

potted history and the background to the methods used by the software.

The Flood Studies Report, Volume 1, Chapters 4 and 6 detail approaches for

determining runoff from ungauged catchments. These have been modified in

subsequent Flood Studies Supplementary Reports Nos 5, 14 and 16. Ciria

Book 14, 1993, takes these modifications into account and provides clear

worked examples of the methodologies. These may also be used on partly

urbanised catchments.

On small catchments, less than 25km2, the IH 124 equation for QBAR (and

the equation for the instantaneous time to peak for the unit hydrograph

approach) may be used in lieu of those suggested in Ciria Book 14 but

otherwise the detailed approach is unchanged.

Comparisons between the FSR and FEH methods are contained in FEH

Volumes 3 and 4, 1999. The difficulty in obtaining digitally derived data for

small catchments and the relative complexity of developing growth curves

using FEH methodology are reasons for the continuing use of the FSR

approach in appropriate circumstances on small catchments.

We have also included the ADAS method as it is widely used but it wasdeveloped for the design of field drains and uses far less sites than the IH 124

report which included 6 ADAS sites in its 87 small catchments.

In summary therefore the calculation to determine discharge from ungauged

catchments may be done using ADAS 345 reference or IH 124 (Institute of

Hydrology Report No. 124 – Flood estimation for small catchments). A third

method is also available based on Flood Estimation Handbook data but it is

usually used on catchments larger than 20km2.




The IH method is based on the Flood Studies Report approach and developed

for use on catchments less than 25 km2. It yields the Mean Annual Maximum

Flood (QBAR). This reference also recommends the use of Ciria Book 14 to

generate Growth Factors. These are used to convert QBAR to different return

periods for different regions in the UK. This method has therefore beenadopted in the software and full tables of return period floods for the regions

of the UK are presented. Information for Ireland is also given in this

appendix.

The ADAS document does not refer to any return period but yields a 'Peak

Flood Flow'. However ADAS has confirmed that for 'Grass' as the dominant

crop type the return period of the flow is 1 year. For other crop types

different return periods have been used but if we assume 'greenfield runoff'means grassland then ADAS yields a 1 year return period (or 100% annual

probability).

A 1 year peak runoff may be converted to a Mean Annual Flood using Table

1 of FSSR No 2, 1977. The Mean Annual Flood may then be converted to

other return periods using the method described for IH 124 above. The table

of return period flows is only available for 'grass' as the dominant crop type.

The Flood Estimation Handbook method yields the Median Annual

Maximum Flood (QMED). The software does not cover the FEH method of

developing growth curves and engineers must refer to Vol 3 of the FEH

handbook to generate flood flows for different return periods. The FEH

approach is intended for larger sites and the method cannot be applied to

catchments smaller than 50ha (0.5km2).

The statutory authority will advise on the approved method. Specifications

have been changed in the recent past and they may alter again. At the time of

writing the Interim Code of Practice for Sustainable Drainage Systems, July

2004, recommended the use of a modified IH 124 for catchments less than

200 hectares and it has dropped the use of ADAS. The Highways Authority

(HA 106) however recommends the use of ADAS up to 40 hectares and

thereafter IH 124. Source Control therefore supports ADAS, IH 124 and the

modified IH 124 under the ICP SUDS tab. Examples of the use of each

follow in this appendix.




These methods are statistically based and yield the peak value of the flood. If

the full flow hydrograph is required this must be generated using the rainfall

runoff unit hydrographs discussed in Appendix iv. However the IH and FEH

statistical methods of predicting peak flows may be used to adjust the

parameters of the Unit Hydrographs and more information is available on thisin FEH Volume 3 chapter 10.2.

The user must be suitably qualified in accordance with the requirements of

the FEH manuals and CD and should be familiar with the above references

and the notes supplied in the On Line Help.

The ADAS method

Reference Book 345 – The design of field drainage pipe systems.(Recommended for sites up to 40 ha – HA 106/04).

We recommend that you purchase ADAS 345 and follow the example in

Appendix 5. A similar example is discussed here.

Before you run the software prepare the following data.

1.

Determine the catchment area in hectares.2. Determine the maximum length of catchment in metres.3. Determine the average slope of catchment Height/Length.

4. Determine the risk category (return period) for the catchment. (In ADAS

345 this is determined by the dominant crop type. ADAS has confirmed that

selecting “Grass” from the chart you are actually selecting the return period

of 2 years).5. Determine the average rainfall in mm from Appendix 1 of the above

reference or the Flood Studies Report.

Determine the soil type factor ST from the table in Appendix 5:

Permeability class ST Very slow 1

Slow to Mod 0.8

Moderate 0.5

Very Rapid 0.1

(There are more details available from the above reference).




Source Control

Open Source Control and at the Open Screen double click the Rural Runoff

(QBAR/ADAS) icon to access the rural runoff statistical methods. It may

also be accessed at all other times through the File menu.

Click on the ADAS 345 tab and enter the data as shown.




Click the Calculator button and the results of the Mean Annual Flood (Q0)

are shown along with the Return Period Flood section which displays a

matrix of peak flows for various return periods and regions. The Total peak

flow and Return Period Flood table includes the percentage paved if it has

been specified.

This is sufficient data to obtain the ADAS Peak Flood Flow. It is often

necessary to obtain the runoff for a variety of return periods. For the purposes

of applying the growth curves for the different return periods the grass runoff

is assumed to be a 1 year return period and converted to the Mean Annual

Flood using FSSR 2. QBAR may be combined with the FSR growth curves

for the 10 regions of the UK. (Four growth curves for Ireland are also

supported after Cawley and Cunnane. The growth curve for the 1 year RPhas been assumed to be 0.85 for Ireland. Any area that has not been covered

may be input via the Growth Curve editor). M J Hall, D L Hockin and J B

Ellis (Ciria Book 14) devised a method for combining these growth factors

with a degree of urbanisation for UK catchments. It is the method

recommended for use with IH 124 and this method has been implemented in

the software.

The specified return period is in the third column and the line of resultshighlighted is for the required Region.

The percentage paved is taken as the percentage Urbanisation for the

purposes of applying the growth curves. However this is not strictly correct

as the urbanisation figure is usually larger than the paved area. However

ADAS only allows a small percentage paved and any error would be small.

ADAS suggests that the unpaved result (paved area = 0) is simply increased

by the percentage paved but warns that if the paved area exceeds 10% of the

catchment then the method is not appropriate. If the amount of urbanisation

were significant then the IH 124 method, which specifically recommends the

Ciria Book 14 method for partly urbanised catchments, would be better

suited.

If the allowable discharge is to be based on the Greenfield runoff from the

undeveloped site then the percentage paved should be set to zero, the

dominant crop type to Grass (i.e. return period set to 2 years) and the ADAS

method is applicable to sites less than 30 ha.




ICP for SUDS

Recommended for sites <200haSimilar to IH 124 but for areas <50ha the results are linearly interpolated

from the 50ha discharge. Outputs 1, 30 and 100 year RP discharges asstandard in compliance with ICP for SUDS. A 200 year RP may be specified

for Scotland.

QBAR estimation for small rural catchments.Click on the ICP SUDS tab.

Enter the required Return Period

RP = 200 years

The area of the catchment is measured in hectares.

Area = 30ha

Note: Hectares have been chosen instead of km2, as this is consistent with

the rest of the program suite and urban drainage design.

Obtain the average annual rainfall; SAAR from the FSR maps.

SAAR = 800mm

Enter the soil type based on the 5 soil categories.

The Soil values are 0.15, 0.3, 0.4, 0.45, 0.5 for soil types 1 to 5 respectively.

(Soil type from the Wallingford procedure maps).

Soil = 0.4

QBAR estimation for urban catchmentsIH 124 recommends the use of the Ciria guide to the design of flood storage

reservoirs (Ciria Book 14, Hall et al, 1993). This also provides for the

estimate of flows for different return periods based on the FSR regional

growth curves.




Enter the data as below and click the Calculator button.

The region and the fraction of urbanisation are required variables for this

method. The fraction of urbanisation, URBAN, measured under the FSRmethod is the area coloured orange on a 1:50000 Ordinance Survey map.

This differs from the measurement of the digitally derived variable URBEXT

available from the FEH CD. URBAN can also be estimated as

2.05*URBEXT (FEH Vol 4, Appendix B).

URBAN = 0

Note: For greenfield runoff estimation URBAN should be set to zero.

The UK is divided into 10 regions for growth factors. Click on the drop downmenu and select Region 9.

Region (Wales) = 9

The QBAR rural is shown which assumes no development and the QBAR

urban figure would show the increased runoff due to urbanisation.

Return Period Flood shows the selected return period alongside the 1, 30 and

100 year return period. The results for the selected region are highlighted.




IH 124 method

Recommended for sites <25km2

(HA 106/04 recommends use on sites >40ha)

QBAR estimation for small rural catchments.Click on the IH 124 tab.

Enter the required Return Period

RP = 75 years


Area = 55ha

Note: Hectares have been chosen instead of km2, as this is consistent with


Note: If an area less than 50ha is entered the software will provide a

warning that the linearly interpolating is not used and the ICP SUDS tab

may be more suitable.


SAAR = 800mm

Enter the soil type based on the 5 soil categories.

The Soil values are 0.15, 0.3, 0.4, 0.45, 0.5 for soil types 1 to 5 respectively.

(Soil type from the Wallingford procedure maps).

Soil = 0.4

QBAR estimation for urban catchmentsIH 124 recommends the use of the Ciria guide to the design of flood storage

reservoirs (Ciria Book 14, Hall et al, 1993). This also provides for the

estimate of flows for different return periods based on the FSR regional

growth curves. Four growth curves for Ireland are also supported after

Cawley and Cunnane. The growth curve for the 1 year RP has been assumed

to be 0.85 for Ireland. Any area that has not been covered may be input via

the Growth Curve editor.




The region and the fraction of urbanisation are required variables for this

method.The fraction of urbanisation, URBAN, measured under the FSR

method is the area coloured orange on a 1:50000 Ordinance Survey map.

This differs from the measurement of the digitally derived variable URBEXT

available from the FEH CD. URBAN can also be estimated as2.05*URBEXT (FEH Vol 4, Appendix B).

URBAN = 0.10

The UK is divided into 10 regions for growth factors. Click on the dropdown

menu and select Region 9.

Region (Wales) = 9

Click the Calculator button.

The QBAR rural is shown which assumes no development and the higher

QBAR urban figure shows the increased runoff due to 0.10 urbanisation.

The Return Period Flood spreadsheet displays the variation in runoff from

each region for a range of return periods. The selected return period is shown

alongside return periods from 2 to 1000 years. The results for the selected

region are highlighted.




QMED estimation using the FEH method

Recommended for larger sites – Interim Code of Practice for Sustainable

Drainage Systems, July 2004

Select the FEH tab. Click on the button next to Site Location and import the

EXAMPLEQMED.csv file from the \Micro Drainage 2014\Data directory.

Enter the area in hectares as shown (4000 ha) – this may differ from the area

imported from the FEH CD if the boundaries of the site are different from

those selected on the CD. However you should attempt to select an area on

the FEH CD that closely corresponds to your site or the soil variables and

other details may not be representative.

Click the Calculator button and urban and rural values of QMED are

displayed.

The 'Interim Code of Practice for Sustainable Drainage Systems', July 2004

recommends that the use of the FEH method should be considered for

catchments larger than 2 km2. The program calculates the estimation of

QMED (median annual storm – return period 2 years). However the

derivation of growth curves requires pooled catchments based on

hydrological similarity and the user is referred to the FEH manual volume 3




for more information on this approach which is not covered here.

The variables for QMED estimation are obtained from the FEH CD. A How

do I example is supplied with the software (and is available from the Help

menu) for those who are not familiar with the operation of the FEH CD.Follow this example to produce a .CSV file for your site.

Greenfield Runoff Volume

Click on the Greenfield Volume tab.

Check the required Return Period and Storm Duration

RP = 100 years

SD = 360 mins

The M5-60 and ratio R can either be entered using the map or manually.

M5-60 = 20.00

Ratio R = 0.4

Check that the Areal Reduction Factor is set to 1.00.


Area = 55ha


SAAR = 800mm

For design purposes the Catchment Wetness Index (CWI) is a function of

SAAR and is automatically calculated.

CWI = 117.339

the SPR factors applied to each soil type differ from the SOIL factors used in

the Wallingford PR equation. Instead of factors ranging from 0.15 to 0.5 the

following are used:

Soil Type 1, SPR = 10

Type 2, SPR = 30

Type 3, SPR = 37

Type 4, SPR = 47

Type 5, SPR = 53




If the site covers more than one soil type then the SPR is weighted based on

the fractions of each area covered by the soil types. In this example we assume

that 30% of the site has soil type 3 and the remainder has soil type 2.

SPR = 0.3*37 + 0.7*30 = 32.1Click the Calculator button and the total Greenfield Runoff Volume (m³) and

Percentage Runoff (PR%) are given.



Appendix iv Page iv.1


Appendix ivUnit Hydrograph



Page iv.2 Appendix iv

Why Use Unit Hydrographs?Urban Drainage simulation programs are sometimes referred to as time-area

methods. These methods are based on rainfall falling on mostly paved

catchments and the runoff generated routed through the pipe network. Theurban runoff equations used are based on the Wallingford Procedure (or other

values may be substituted). These methods have usually concentrated on the

portion of runoff that is “flash” or fast runoff. This runoff is important on

developed sites as it contributes most to the peak flows. The Wallingford

Procedure was not intended for use on sites less than 20% paved.

The runoff from undeveloped or rural sites is slower. The method

traditionally used to develop runoff hydrographs from these sites has been the

unit hydrograph method. It too requires rainfall and a runoff relationship to

generate flows and for that reason is called a rainfall-runoff method. There

are similarities with the urban time-area methods and it is possible to set the

variables of the Wallingford Procedure to give similar results but it relies

heavily on the experience of the engineer. However, as the unit hydrograph

method is available, and comprehensive research has been conducted into its

use on rural sites, XP Solutions has implemented the method to allow

engineers to use a more appropriate approach to undeveloped catchments (or

parts of a catchment that are largely undeveloped).

Whether it be an urban or a rural catchment the response time of the site is

very important. The faster the runoff reaches a point the higher the peak flow.

In urban drainage these response times are expressed as a Time of

Concentration or Time-Area. In the Unit Hydrograph terminology variables

such as Time to Peak and Lag Time are used to define a catchments response

time. More importantly the Unit Hydrograph method has calibrated equations

to determine the response time on undeveloped catchments. These may be predicted from catchment characteristics or if measured data exists the

methods of determining Lag are detailed in the FEH manual.

The other variable that is important in all drainage calculations is the

percentage runoff. In urban drainage methods the percentage runoff model

centres on the percentage paved area as this is critical. However, the rural

models pay more attention to soil characteristics and the FSR, FEH and

ReFH unit hydrograph methods have more appropriate equations for largely

unpaved catchments. Urban drainage engineers may be surprised by the




degree of runoff predicted by the FSR, FEH and ReFH Unit Hydrograph

models but they must remember that the runoff is usually over a much longer

time period i.e. rural sites have a much longer response time.

When to use the UH methodSimulation APT and Source Control APT allow the engineer to combine

flows from urban and rural catchments. As both methods are rainfall-runoff

methods the same rainfall event may be used to generate flows from both the

rural and urban elements of the catchments (one complication is that return

periods may differ for FEH and FSR methods – see help for details).

The Unit Hydrograph method may also be used on partly urbanised

catchments and here there may be an overlap with the urban simulationapproach. However, in these cases it is a matter of judgement which method

is best and no hard and fast rule exists.

The FEH advises that if the variable URBEXT exceeds 0.5 (Volume 4,chapter 9.3.) then the Unit Hydrograph method should not be used. This is

not much help as it implies that the site is very developed and the usual urban

drainage approach should be taken. If the site is largely sewered and contains

infiltration and storage structures then the normal urban simulation approachis likely to be more accurate. However, Micro Drainage is uniquely powerful

in that it allows the engineer to divide the site into sub-catchments of

developed and undeveloped areas and to use the Time-Area and Unit

Hydrograph methods as appropriate.

How to Define the Different AreasThe Wallingford Procedure runoff and time-area approach is used on all

urban areas. These are the areas that you have input in the System 1 program,any time-area input in Source Control and Simulation, or any areas you have

defined in Simulation APT network details.

The Unit Hydrograph method is applied only to the areas defined in the

Generate Unit Hydrograph sections of Source Control APT and Simulation

APT programs. These areas are entirely separate from the Urban Areas

described above and they must not be duplicated in the inputs described

above for urban areas.




How do UH relate to Peak Flow prediction?Methods for predicting peak flood flows using statistical methods are

described in Appendix iii. These differ in a number of respects from the Unit

Hydrograph method. Firstly they are not rainfall-runoff methods as they are

not directly related to rainfall events. They are derived from the statistical

analysis of flows from catchments. Of course the flows have been generated

from rainfall events but the analysis is based on the resultant flows. Secondly

they generate peak flows only, which cannot be used for simulations or

volume calculations. However, these peaks should relate to the peak flow

generated by the unit hydrograph and because of this they may be used to

calibrate the unit hydrograph.

Adjusting the parameters of the rainfall-runoff model using the statisticalmethods provided in Source Control APT is discussed in FEH Volume 3,

Chapter 10.

Which method - FSR, FEH or ReFH Unit Hydrographs?The Revitalised Flood Hydrograph model (ReFH), July 2005, is the latest

method published in the UK and therefore this method should be the

preferred approach if the digital input variables can be obtained.

The triangular instantaneous unit hydrograph of the FSR and FEH methods

has been replaced by a kinked triangle. The equation for Tp has been

modified and a variable Base Flow introduced. The runoff equation has also

been changed and is based on a loss model derived from the Probability

Distributed Model (PDM) developed by Moore.

There is not a one to one correlation between rainfall return periods and

runoff return periods in the FEH and FSR methods. In rural areas(URBEXT<0.125), for example, a 140 year rainfall RP is needed to produce

a 100 year runoff. This poses a difficulty when combining the Wallingford

procedure with these unit hydrograph methods. This is resolved in ReFH as

both the Wallingford Procedure and ReFH produce the same return period

runoff as the rainfall event used to generate the flows.

The ReFH method modifies the FEH DDF design rainfall by a seasonal

correction factor for summer and winter. Also the initial soil moisture storage

is seasonally corrected for design storms and varies with return period.




A detailed description of the ReFH model is contained in Revitalisation of

the FSR/FEH rainfall runoff method, R&D Technical Report FD1913/TR.

The Flood Estimation Handbook Volume 4 may be referred to for a

comprehensive discussion of the differences between FSR and FEH.

The FEH method is closely based on the FSR method. The biggest difference

is that the FEH rainfall model can produce significantly different results to

the FSR rainfall generation. However, as is discussed later, the FSR method

may be used in the software with any rainfall including rainfall files

generated using the FEH rainfall model.

The FSR approach implemented in the software is that modified by the IoH124 document for small catchments (less than 25km

2). It has the advantage

that most of the variables are readily understandable and available. If you are

new to the unit hydrograph approach it may help your understanding to work

through the FSR method and identify the comparable variables in the FEH

and ReFH methods.

The ReFH and FEH approaches rely on the digitally derived data available on

the FEH CD. It can be difficult to obtain data for a small catchment from theCD and it is important to check the data with a local site survey. If the

boundary of a river catchment were a few metres out it would make little

difference to a 300km2 catchment but it could be very significant for a 50ha

catchment adjacent to that boundary.

The ReFH method is the latest approach and as such may be used if the site

can be identified on the FEH CD. However, small catchments can present

particular difficulties and the choice of variables may be more important than

the choice of methods. Local information on existing watercourses and

culvert capacity and the frequency of exceedance should be sought to verify

the model. Any measured data available on the site or adjacent sites should

be sought. Further information on the performance of the rainfall-runoff

method is available in FEH, Volume 4, Chapter 7 and R&D Technical Report

FD1913/TR.

As the ReFH and the FEH methods use the same digital source for their data

only the more recent ReFH method is illustrated in this example.




FSR Unit Hydrograph method(Rainfall runoff method) Users should be familiar with the Flood Studies Report and we also

recommend Ciria Book 14 as it details the procedure and the method ofcalculation clearly. The only deviation from Ciria 14 is that the equation for

Tp(0) has been taken from IH 124 and not FSSR 16 as the latter is not as

consistent for catchments < 25 km2. There are also notes in the On Line Help

that should be thoroughly reviewed.

The following example is used for illustration:


Area = 30ha

Note: Hectares have been chosen instead of km , as this is consistent with


Measure the length of the main channel as described in Book 14. On a small

site (less than 2500ha) any reasonable approach can be used.

MSL = 600m

Note: Again metres have been used in lieu of km to be consistent.

Measure the main channel slope. This is the average slope of the main channel

between points 10% and 85% of the channel length measured from the

channel outlet. In other words ignore the top 15% and the bottom 10% of the

channel. The program requires you to enter the two heights and it calculatesthe slope.

H(85%) = 205m

H(10%) = 203m

Obtain the average annual rainfall.

SAAR = 800mm




The fraction of urbanisation, URBAN, measured under the FSR method is the

area coloured orange on a 1:50000 Ordnance Survey map. This differs from

the measurement of the digitally derived URBEXT available on the FEH CD.

URBAN can also be estimated as 2.05*URBEXT (FEH Vol 4, Appendix B).

URBAN = 0.15

The percentage runoff is derived by reference to the 5 soil types used in the

Wallingford Procedure PR equation for urban runoff. However, the SPR

factors applied to each soil type differ from the SOIL factors used in the

Wallingford PR equation. Instead of factors ranging from 0.15 to 0.5 the

following are used:

Soil Type 1, SPR = 10

Type 2, SPR = 30

Type 3, SPR = 37

Type 4, SPR = 47

Type 5, SPR = 53

If the site covers more than one soil type then the SPR is weighted based on

the fractions of each area covered by the soil types. In this example we assumethat 30% of the site has soil type 3 and the remainder has soil type 2.

SPR = 0.3*37 + 0.7*30 = 32.1

This data may be used with either Source Control or Simulation if APT has

also been purchased. The Source Control module allows a unit hydrograph to

be generated if, under Global Variables an Input Hydrograph has been chosen

in the Additional Inflow pull down option. As the rest of the procedure is

identical to Simulation, only a simulation example is presented here.

Run Simulation A.P.T. using your preferred method and at the Open Screen

double click Open Existing File. From the data supplied with the software

choose Appendix4FSR.mdx. We will assume that this site has a largely

undeveloped catchment (say 15% urbanised) draining into pipe 3.000.




At the Simulation Criteria set the Return Period to 30 years and the Storm

Duration to 120 minutes.

Under the Network menu select Input/Unit Hydrographs.

For Hydrograph 1 enter the DS (downstream) Pipe Number as 3.000 andselect Unit for hydrograph method.

Then click the Generate button at the bottom of the form.

The Generate Unit Hydrograph form will appear. The Return Period and

Storm Duration are identical to those set in the Simulation Criteria and will

be used on both the Urban (the normal areas detailed in the Network Details)

and the Rural (Unit Hydrograph) elements of the catchment. If the rural area

is some distance from the development then there could be a different M5-60

and Ratio R for both areas.




Enter the above measured data as shown for the FSR Input tab.

For design purposes the Catchment Wetness Index (CWI) is a function of

SAAR and is automatically calculated. The time to peak Tp(0) is calculated

from these site characteristics using the recommended equation from IH 124

for general use. IH 124 also claims it to be more suitable for catchments <

25km

2

than the FSSR 16 equation.

If the LAG time has been measured on the site it may be specified and this

will be used to calculate Tp(0) in preference to the catchment characteristics

– refer to IH 124. In this example no site measurements are available and the

LAG time is not specified.

FEH, Volume 4, Chapter 7 discusses the performance of FSR methods. The

most important variables for all rainfall runoff methods are time to peak Tp

(related in urban drainage to Time of Concentration and rural drainage to Lag

Time) and percentage runoff. Small catchments may be difficult to define in

terms of catchment characteristics and where measured data on Tp is

available it will greatly improve the results. The Source Control APT

program also provides information on statistical peak flow and this

information should not be ignored when verifying the results of the FSR

method. Adjusting the parameters of the FSR method using the statistical

techniques (QBAR and QMED prediction – see Appendix iii) is discussed in

FEH Volume 3, Chapter 10.2.




Click OK on the Input / Unit Hydrographs and analyse the network At Fine

time step. Select No to the warnings to accept the specified run times.

Open the Hydrograph Tables from the Results menu. Select pipe 3.000 fromthe dropdown. Select the View Unit Hydrograph button and the Unit

Hydrograph Results are displayed

View Unit Hydrograph

The profile graph displays a 120 minute storm, based on the rainfall details

specified.

Normally if a hydrograph is specified a different hydrograph will have to be

input to correspond to each storm event. However, the use of the unit

hydrograph method to define the flow overcomes this problem. If the rainfall

storm duration or return period in the Simulation Criteria change then a newunit hydrograph will be generated.

This means that a Seasonal Return Period Wizard may be run and the Unit

Hydrographs will be automatically generated to correspond to the different

rainfall events. This ensures that the 'developed' runoff generated from the

areas defined in System 1 (or the Network Details) will be combined with

'rural' runoff generated from the Unit Hydrographs for the same return

periods and storm durations. Similarly if rainfall files are used to generaterunoff from the paved areas then the same rainfall data will be used in the




Unit Hydrograph. Further details of return periods to be used with Unit

Hydrograph methods are contained in the Help.

For more details on the convolution of the net rainfall and the unit

hydrograph refer to Ciria Book 14 for the method of calculation.

The convolution of the net rainfall and the unit hydrograph is presented for

verification purposes under the Unit Hydrograph tab

View the graphs for pipe 3.000.




The only flow entering this pipe has been generated from the unit

hydrograph. It can be seen that the maximum flow shown occurs just before

240 minutes and a longer analysis may be required. If however Yes wasselected from the prompt, the analysis would have been run for 324mins

(Twice TP(0)). This is because the instantaneous time to peak Tp(0) is 162

minutes which is much longer than the time of concentration of the

developed catchment.

View the graphs for pipe 1.004.

Observe that peak flow generated by the developed catchment occurs at 64

minutes, which is 3 hours before the peak from the rural area.You may generate a longer analysis by changing the Run Time (mins) in the

Simulation Criteria to 720 minute duration.

However, the 120 minute storm is not critical and the critical storm duration

is never less than Tp(0), the instantaneous time to peak of the unit

hydrograph. It is likely to be of the order of 2Tp(0) – see equation 3.16, Ciria

Book 14. There is no need, however, to speculate on the critical duration as a

wizard is provided in the software to run all the storm durations. This wizard

will run each storm for twice its duration and the critical duration should




therefore contain the peak of the hydrograph.

The engineer should verify this before relying on the summary of results.

Run the Seasonal Return Period Wizard from the Wizards menu. Full details

of running Wizards are given in Example 8 on Advanced Productivity Tools.

Follow the instructions on screen and select all storm durations at Step 2. At

Step 3 clear the listed return periods and specify a 30 year return period and

proceed to run the wizard.

A message at the end of the wizard will confirm that you have specified a

unit hydrograph and therefore a new input hydrograph will be generated for

each storm in the wizard. Click No to the second message to accept runtimes.

Discussion of resultsSelect the Critical Storm on the Summary. The urban area discharges down

pipe 1.000 through to pipe 1.003. Therefore if you wish to view the urbanhydrograph on its own you must view the graph of pipe 1.003 or the

hydrograph tables for this pipe.

The unit hydrograph is the only input into pipe 3.000. Therefore if you wishto view the rural hydrograph on its own then view the graph of pipe 3.000.

The critical storm for pipe 3.000 is also the critical storm for the rural area as

it is the only discharge into pipe 3.000. The Unit Hydrograph discharging

into pipe 3.000 has a critical storm of 360 minutes which is not unexpected.

Using the Storm Selector (if it is not visible it may be called from the Results

menu) choose the 360 minute summer storm. As with all storms generated

automatically by the wizard the program has output results for twice itsduration. The peak of the rural hydrograph is shown on the graphs for the 720

minute run of the 360 minute storm. The peak water levels and flows are

therefore correct for the 360 minute storm.

The shorter less critical storms may not contain their peaks within the

analysis duration. If the 30 minute storm is viewed then only 60 minutes of

results are shown. You can see that the hydrograph is still rising and has not

reached its peak after 60 minutes. However, as already stated the critical

storm duration is longer than the time to peak of the unit hydrograph and




when a storm longer than this is run the maximum flow will be contained on

the results.

Now select the graphs for pipe 1.004. This pipe is at the confluence of the

urban and the rural runoff. The rural element peaks for a 360 minute durationstorm but this does not provide a higher peak flow than that generated by the

urban element for short duration storms. As the response time of the rural

area (a function of the time to peak) is so long the urban and rural

hydrographs do not coincide. The rural flows increase the peak discharge in

pipe 1.004 by only a small amount during the 15 minute storm which

produces the largest flow for the combined site.

The volume of runoff (area under the flow graph) from the rural areahowever, is large and if the discharge from pipe 1.004 were restricted the

effect of the rural runoff would be very significant on storage.

Note: The FSR method is defaulted to if FSR rainfall (M5-60, r) is

specified. However, in many locations in the UK the FEH rainfall is

significantly higher than the older FSR rainfall generation. It is possible to

use the above method with FEH rainfall by saving the FEH data as a series

of files, which may be accomplished by using Rainfall Profile in the Editmenu of Module Selector available from the Window menu. This option

may be used on smaller catchments where it may be difficult to obtain

good digital information on catchment characteristics from the FEH CD.

However, if the digital data can be reasonably determined then the FEH

method may be used with FEH rainfall. The decision should be made by an

experienced engineer familiar with Volume 4 of FEH and no general

recommendation is possible.




ReFH Unit Hydrograph Method(Rainfall runoff method)Although the FEH method remains in the software the ReFH method is used

here as it shares several variables with the FEH method and is the latestmethod. Users must be familiar with the Revitalisation of the FSR/FEH

rainfall runoff method, R&D Technical Report FD1913/TR. As the FSR

method requires more site measurements to be conducted by the engineer, the

above FSR example should be run first to gain a better insight into the

operation of the unit hydrograph method.

The method is similar to the FSR method but there are some important

differences. The rainfall derivation is the newer (1999) FEH model, with

updated data, and may result in significantly different results from the FSR

methodology. This is discussed in FEH Volume 1. The other variables used

are obtained from the FEH CD-ROM.

The percentage runoff equations have been altered from the manually derived

FSR method to account for differences in the digitally derived variables; it

has also been updated to allow the percentage runoff to vary throughout the

storm. ReFH also has an updated equation for Tp for use with digitally

derived catchment descriptors, similar to the FEH method.

The rainfall variables and the catchment characteristics for the site are

obtained from the FEH CD. A How do I example is supplied with the

software for those who are not familiar with the operation of the FEH CD.

Follow this example to produce a .CSV file for your site.

As with the FSR example this data may be used with either Source Control or

Simulation if APT has also been purchased. The Source Control moduleallows a unit hydrograph to be generated if, under Global Variables, an Input

Hydrograph has been chosen in the Additional Inflow pull down option. As

the rest of the procedure is identical to Simulation, only a simulation example

is presented here.

Run Simulation A.P.T. using your preferred method and select Open Existing

File. From the data supplied with the software choose Appendix4ReFH.mdx.

We will assume that this site has a largely undeveloped catchment draininginto pipe 3.000.




At the Simulation Criteria check the Rainfall Model is set to FEH Rainfall

and the file Penwood.csv has been loaded into the Site Location, this contains

the rainfall data and catchment characteristics for the site.

Set the Return Period to 30 years and the Storm Duration to 120 minutes inthe Simulation Criteria. Accept all the other defaults and click OK .

Under the Network menu select Input / Unit Hydrographs.

For Hydrograph 1 enter the DS (downstream) Pipe Number as 3.000 and

select Unit for the Hydrograph Method. Then click the Generate button.

Select the ReFH Input tab in the Generate Unit Hydrograph form, and as in

the Simulation Criteria, double click on Site Location (or click on the

adjacent button). Call in the FEH csv file entitled Penwood.csv, which now

transfers both the rainfall data and catchment characteristics for the site.

The rainfall data may differ slightly from that called into the Simulation

Criteria because the 'Urban' data is always the 1 km data while the rural data




is the catchment average. The reason for this is that most urban development

sites are less than 100ha while rural catchments may be tens of thousands of

hectares and the average rainfall characteristics may differ significantly from

the 1 km variables.

Check the catchment characteristics. The Areal Reduction Factor will be read

from the Simulation Criteria, we will accept this value, however, you may

generate the value based on area and storm duration by clicking the

calculator. From site surveys the area is 49 hectares and this should be

entered instead of the 57 hectares shown. The variables that relate to site

slope and stream length have been confirmed by the site survey and are

unchanged. Development has taken place in this area and to allow for any

future development we are going to assume an URBEXT of 0.15 (equivalentto the FSR URBAN value of 0.308, FEH Vol 4 App B).

As this is a small site any measurement of Lag time should be specified and

this will be used to calculate Tp in preference to the value estimated from the

catchment characteristics (see FEH Volume 4 Chapter 7).The Return Period

and Storm Duration are taken from the Simulation Criteria and will be used

on both the urban (the normal areas detailed in the Network Details) and the

rural (Unit Hydrograph) elements of the catchment.

The data should be as shown below for the ReFH Input.




If known data is available the Lag time may be used to vary the time to peak

TP. Try a Lag time of say 1 hour and see how this varies the flow. When you

are finished experimenting delete the Lag time and restore the variables to

those contained on the above before proceeding.

Click OK on the Input/Unit Hydrographs form. Analyse the network At Fine

time step.

Open the Hydrograph Tables from the Results menu. Select pipe 3.000 from

the dropdown. Select the View Unit Hydrograph button and the Unit

Hydrograph Results are displayed

View Unit Hydrograph

The results for a 30 yr RP, 120 minute storm are shown.

Alpha represents a correction factor applied to the initial soil moisture which

is used to calculate the percentage runoff. The value is seasonally dependent

and is only used for Design Rainfall events.

The convolution of the net rainfall and the unit hydrograph is presented for

verification purposes under the Unit Hydrograph tab. Refer to Revitalisation

of the FSR/FEH rainfall runoff method, R&D Technical Report FD1913/TR.




View the graphs for pipe 3.000. This will show the results for the unit

hydrograph analysis as it enters upstream of pipe 3.000.

Again the critical storm can be found by running the Seasonal Return Period

Wizard. Follow the procedure as described for FSR and the critical storm is

the 180 minute storm. This is approximately 2Tp, which is to be expected.

Discussion of resultsRefer to the FSR method discussion of results for an explanation of which

flows are generated by the urban area and which result from the unit

hydrograph.

The rural area is very large relative to the urban catchment. In this case the

rural runoff is dominant in producing both the critical peak flow at the outfall

of the combined catchments and the critical volume. Contrast this with theresults for the smaller rural area used in the FSR example. It is not sufficient

to simply look at the summary of results. A thorough review of the

hydrographs in both tabular and graphical form is essential to obtain an

understanding of the dynamics of the runoff.

There are worked examples of the FEH unit hydrograph method in chapter 6

of FEH, should you wish to look at them. The above information is intended

as a help to getting started with the Unit Hydrograph method. The runoff




from undeveloped catchments is very variable and much more difficult to

predict than urban drainage. Engineering judgement must be exercised and

engineers who are not familiar with Revitalisation of the FSR/FEH rainfall

runoff method, R&D Technical Report FD1913/TR should not use this

method.



Appendix v Page v.1


Appendix v Allowable Discharge for Example 8



Page v.2 Appendix v

Allowable DischargesThis Appendix is referenced from and forms part of Example 8.

Knowledge of the Interim Code of Practice approach to allowable dischargesis required for the discussion that follows. The subject is dealt with in detail

in Appendix iii.

For Example 8 the allowable discharge rates are required. Open Source

Control and at the Open Screen double click the Rural Runoff

(QBAR/ADAS) icon. Then click on the ICP SUDS tab.

The input variables for the Example 8 site are shown below and a further

explanation of the method is available in Appendix iii. The SAAR and Soil

values can be loaded from the Map. Click the Map button and select a site

midway between Swindon and Oxford. Alternatively type in the values as

shown.

Click the Calculator button.



Appendix v Page v.3

QBAR is given as 20.1 l/s.

The one year return period event is 17.1 l/s for Region 6.

If the volume of runoff increases after development then the maximumallowable discharge is likely to be QBAR when a 100 year rainfall event falls

on the site. You must also confirm that the 1 year greenfield runoff is not

exceeded for the 1 year event on the developed site.

If this additional runoff can be infiltrated or put into long-term storage then

the maximum allowable discharge may be increased. Then the 1, 30 and 100

year greenfield discharges will be allowed for the 1, 30 and 100 year events

respectively on the developed site.

Example 8 has no infiltration or long term storage so it is assumed that 17.1

l/s should not be exceeded for the 1 year event and that 20.1 l/s should not be

exceeded for the 30 year and the 100 year events.

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