Surface Water Drainage Strategy (SWDS) 5601

Surface Water Drainage Strategy (SWDS) 5601

55 Mountain Echo Avenue

London

E4 7JX

Reference: 5601_SWDS Final v1.0

2

Document Issue Record

Please Note:

This report has been prepared for the exclusive use of the commissioning party and may not be reproduced without prior written

permission from AMBIENTAL Environmental Assessment. All work has been carried out within the terms of the brief using all

reasonable skill, care and diligence. No liability is accepted by AMBIENTAL for the accuracy of data or opinions provided by others

in the preparation of this report, or for any use of this report other than for the purpose for which it was produced.

Contact Us: Ambiental Environmental Assessment

Science Park Square

Brighton, BN1 9SB

www.ambiental.co.uk

UK Office: +44 (0) 20 3857 8530 or +44 (0) 20 3857 8540

Project: Surface Water Drainage Strategy (SWDS)

Prepared for: Heritage Estate Group LTD

Reference: 5601 SWDS

Site Location: 55 Mountain Echo Avenue, London, E4 7JX

Proposed

Development:

The development is for the construction of a block of flats to replace an existing

dwelling.

Consultant Date Signature

Author Tom Vine 29/07/20

Document Check Lydia Sayers 19/08/2020

Authorisation Mark Naumann 20/08/2020


3

Contents

Document Issue Record ............................................................................................................................. 2

Please Note: ........................................................................................................................................... 2

Contact Us:............................................................................................................................................. 2

Contents ..................................................................................................................................................... 3

1. Introduction ....................................................................................................................................... 4

Existing Drainage Infrastructure and Nearby Watercourses ................................................................ 4

Geology and Infiltration Potential ......................................................................................................... 5

Flood Zone and Vulnerability ................................................................................................................. 5

2. SUDS Assessment .............................................................................................................................. 6

Rainwater Harvesting ............................................................................................................................ 8

Geocellular System ................................................................................................................................ 8

Permeable Paving .................................................................................................................................. 8

3. Surface Water Drainage Strategy ...................................................................................................... 9

Runoff rates ........................................................................................................................................... 9

Climate Change .................................................................................................................................... 10

Long Term Storage ............................................................................................................................... 10

Urban Creep ......................................................................................................................................... 10

Attenuation Storage ............................................................................................................................ 10

4. Design Exceedance .......................................................................................................................... 10

5. Water Quality .................................................................................................................................. 11

6. Adoption and Maintenance ............................................................................................................. 11

7. Conclusion ....................................................................................................................................... 13

Appendix 1 – Supporting Information ..................................................................................................... 15

Appendix 2 – Preliminary Surface Water Drainage Strategy Layout ...................................................... 16

Appendix 3 – Calculations ........................................................................................................................ 17

Appendix 4 – CCTV report ....................................................................................................................... 18


4

1. Introduction

Ambiental Environmental Assessment has been appointed by Heritage Estate Group LTD c/o Neil

Squires to undertake a Surface Water Drainage Strategy for the proposed development at 55

Mountain Echo Avenue, London, E4 7JX.

The existing site compromises of a residential building and a garage toward the south of the site.

The redline application boundary area is approximately 1110m2 (0.111ha). The existing

hardstanding area associated with the respective buildings and adjacent paths/driveway totals

approximately 160m2.

Figure 1: Site Location

The development is for the construction of a block of flats to replace an existing dwelling and

garage.

Following development, the total hardstanding area of the site would increase to approximately

640m2 (0.074ha).

The purpose of this assessment is to demonstrate that the development proposal outlined above

can be satisfactorily accommodated without worsening flood risk for the area and without placing

the development itself at risk of flooding, as per National guidance provided within the National

Planning Policy Framework (NPPF) 2018 the National Planning Practice Guidance (NPPG), DEFRA’s

National Standards for Sustainable Drainage and London Borough of Waltham Forest local policy

relating to Sustainable Urban Drainage Systems (SUDS).

Existing Drainage Infrastructure and Nearby Watercourses

The nearest watercourse to the site is the William Grilling Reservoir and is located at approximately 600m to the west.

Site


5

The Thames Water sewer asset plan for the wider site area indicates that the site drains into a public foul sewer located on Mount Echo Avenue. See map in Appendix 1.

There are surface water sewers on Mountain Echo Drive and Mountain Echo Avenue, it is assumed there is an existing connection to the surface water sewer. There are no invert/depths indicated for the storm sewer in Mount Echo Avenue so levels of this drain may need confirmation prior to detailed design. See map in Appendix 1.

A CCTV survey has been undertaken by the client (see appendix 4) but the surveyors were unable to locate access to the storm drainage system.

Geology and Infiltration Potential

The British Geological Survey (BGS) Geology of Britain Viewer indicates that the bedrock underlying

the site is London Clay Formation - Clay, Silt And Sand. The superficial soil deposits in the wider area have not been recorded on the BGS viewer.

Based on the BGS geology information infiltration is not considered to be feasible.

Flood Zone and Vulnerability

The EA’s Flood Map for Planning (Figure 2) demonstrates that the site would be located in Flood Zone 1 (Low Risk). According to the NPPF vulnerability guidance, the proposed residential development would be classified as ‘More Vulnerable’ and is not required to implement the Exception Test.

Figure 2: EA Flood Map for Planning

A review of the EA flood risk from surface water map (Figure 3) has demonstrated that the site is entirely located at ‘Low’ risk of surface water flooding.


6

Figure 3: EA Flood risk from surface water

2. SUDS Assessment

In accordance with the SuDS management train approach, the use of various SuDS measures to reduce and control surface water flows have been considered in detail for the development.

Paragraph 80 of the Planning Practice Guidance of the National Planning Policy Framework (NPPF) states that: Generally, the aim should be to discharge surface run off as high up the following hierarchy of drainage options as reasonably practicable, see Table 2.

The management of surface water has been considered in respect to the SuDS hierarchy (below)

(as detailed in Building Regulations Part H and within the the CIRIA 753 ‘The SUDS Manual’, Section

3.2.3):

To achieve the reduction in site run off rates, the use of various SuDS have been considered for the

development as follows:

SuDS Drainage Hierarchy

Suitability Comment

1. Infiltration x

Due to the geology at the site, infiltration is not

considered to be feasible

2. Discharge to Surface Water x No open waters are located near the site.

3.

Discharge to Surface Water

Sewer, Highway Drain or

another Drainage System

Surface water sewer/drain is located in close

proximity to the site.

4. Discharge to Combined

Sewer x ‐

5.

Discharge to a foul sewer

(should not be considered

as a possible option)

x ‐

Table 1: SuDS Hierarchy


7

Suitability of SuDS Components

SuDS Component

Description Suitability

Infiltrating SuDS Infiltration can contribute to reducing runoff rates and volumes while supporting baseflow and groundwater recharge processes. The suitability and infiltration rate depends on the permeability of the surrounding soils.

x

Permeable Pavement

Pervious surfaces can be used in combination with aggregate sub‐base and/or geocellular/modular storage to attenuate and/or infiltrate runoff from surrounding surfaces and roofs. Liners can be used where ground conditions are not suitable for infiltration.

Green Roofs

Green Roofs provide areas of visual benefit, ecological value, enhanced building performance and the reduction of surface water runoff. They are generally more costly to install and maintain than conventional roofs but can provide many long‐term benefits and reduce the on‐site storage volumes.

x

Rainwater Harvesting

Rainwater Harvesting is the collection of rainwater runoff for use. It can be collected form roofs or other impermeable area, stored, treated (where required) and then used as a supply of water for domestic, commercial and industrial properties.

Swales

Swales are designed to convey, treat and attenuate surface water runoff and provide aesthetic and biodiversity benefits. They can replace conventional pipework as a means of conveying runoff, however space constraints of some sites can make it difficult incorporating them into the design.

x

Rills and Channels

Rills and Channels keep runoff on the surface and convey runoff along the surface to downstream SuDS components. They can be incorporated into the design to provide a visually appealing method of conveyance, they also provide effectiveness in pre‐treatment removal of silts.

x

Bioretention Systems

Bioretention systems can reduce runoff rates and volumes and treat pollution through the use of engineer soils and vegetation. They are particularly effective in delivering interception, but can also be an attractive landscape feature whilst providing habitat and biodiversity.

x

Retention Ponds and Wetlands

Ponds and Wetlands are features with a permanent pool of water that provide both attenuation and treatment of surface water runoff. They enhance treatment processes and have great amenity and biodiversity benefits. Often a flow control system at the outfall controls the rates of discharge for a range of water levels during storm events.

x

Detention Basins

Detention Basins are landscaped depressions that are usually dry except during and immediately following storm events, and can be used as a recreational or other amenity facility. They generally appropriate to manage high volumes of surface water from larger sites such as a neighbourhoods.

x

Geocellular Systems

Attenuation storage tanks are used to create a below‐ground void space for the temporary storage of surface water before infiltration, controlled release or use. The inherent flexibility in size and shape means they can be tailored to suit the specific characteristics and requirements of any site.

Proprietary Treatment

Systems

Proprietary treatment systems are manufactured products that remove specific pollutants from surface water runoff. They are especially useful where site constraints preclude the use of other methods and can be useful in reducing the maintenance requirements of downstream SuDS

Filter Drains and Filter Strips

Filter drains are shallow trenches filled with stone, gravel that cerate temporary subsurface storage for the attenuation, conveyance and filtration of surface water runoff. Filter strips are uniformly graded and gently sloping strips of grass or dense vegetation, designed to treat runoff from adjacent impermeable areas by promoting sedimentation, filtration and infiltration.

x

Table 2: Suitability of SuDS Components


8

It has been indicated in Table 3 above, that several SuDS components are deemed appropriate to

be used in the following SuDS management train.

SuDS components should be designed to accommodate and dispose of runoff from storms up to

and including the 1:100 year +40% climate change event without flooding.

Rainwater Harvesting

Rainwater harvesting (RWH) Systems should be considered for rainwater re‐use. Rainwater

harvesting can take various forms including simple water butts to utilise runoff for watering and

irrigation, to more complex pumped RWH systems to be used in grey water uses. It is strongly

recommended that rainwater harvesting is considered, however, the viability and suitability of an

RWH system should be reviewed by a specialist to determine the suitability in context to the rest

of the site proposals. For the purposes of attenuation and storage calculations, it is considered the

harvesting devices are full at the time of the design rainfall event.

Geocellular System

Geocellular Systems are generally built by placing together (e.g. stacking) cuboid plastic structures

with very high void ratios (90‐95%). The formed volume is then surrounded by a permeable

geotextile and backfilled with the excavated soil to form the attenuation tank.

Within the proposed SuDS scheme, the Geocellular tanks are used to provide the storage volume

requirement and infiltrate runoff. They are to be located within the car parking area, however, the

exact layout is to be determined at the detailed design stage.

Permeable Paving

Permeable paving is proposed in many new external hardstanding areas (within the redline

boundary excluding bin store area to avoid the risk of contamination). The permeable paving will

primarily be designed to be self‐draining (to mimic an equivalent area of soft landscaping). The

paving could be formed by the following make up:

Permeable surfacing as required

Laying Course Material

Geotextile filter

Sub‐Base: 6‐20mm clean crushed stone (depths as required to withstand loading

requirements)

Geotextile filter or impermeable membrane depending on infiltration rates

For conservative purposes, should a site have steep topography, permeable paved areas should

only be considered for runoff interception, treatment and conveyance to downstream SuDS.


9

3. Surface Water Drainage Strategy

In order to mitigate flood risk posed by the proposed development, adequate control measures are required to be considered. This will ensure that surface water runoff is dealt with at source and the flood risk on/off site is not increased over the lifetime of the development.

The drainage strategy proposed herein uses a flow control, geocellular crates and permeable pavement to manage surface water post‐development. The permeable paving would intercept, treat and convey runoff to network while also providing attenuation storage. See proposed preliminary drainage layout in Appendix 2.

Following confirmation of site levels, infiltration tests and wider construction details, the drainage

strategy proposed herein should be reassessed and amended as necessary.

Runoff rates

Greenfield and Brownfield runoff rates have been calculated using Micro Drainage Software and

applying the Institute of Hydrology Report 124 (Marshall and Bayliss, 1994), as recommended in

the CIRIA 753 ‘The SUDS Manual’ for calculating the greenfield runoff rates. See calculations in

Appendix 3.

As DEFRA Report ‘Rainfall runoff management for Developments’ recommends, the design principle is to limit the runoff for events of similar frequency of occurrence to the same peak rate of run as that which takes place from greenfield sites. However, there are two situations where the greenfield flow rate is not actually applied to define the limiting discharge rates:

a) The limit of discharges based on QBAR that are less than 1 l/s/ha for permeable sites as this is seen as being an unreasonable requirement (producing very large storage volumes). QBAR is then set to 1 l/s/ha;

b) Small sites would require impractically small controls to achieve the required flow rates where these are calculated to be less than 5 l/s. In this case a minimum flow of 1 l/s is used as a practical minimum for flow control devices without causing blockage risks.

A minimum flow control opening size of 50mm is provided in Sewers for Adoption 8. In this case a 1 l/s is used as a minimum flow corresponding to a 55mm Hydrobrake. These rates are to be agreed with the relevant planning authority.

The existing runoff rates have also been calculated and summarised in Table 3 below. It can be seen that the proposal is to limit the runoff rates, to rates that will be lower than the existing for all events up to and including 1 in 100 year +CC.

SURFACE WATER DISCHARGE RATES SUMMARY

Area (m2) Discharge Rates (l/s)

1 year QBAR 30 year 100 year

Greenfield Rates 1111 0.4 0.46 1.07 1.74

Brownfield Rates 160 2.40 ‐ 5.90 7.50

Proposed Site (+40% CC) 650 1.00 ‐ 1.00 1.00

Betterment 58% 83% 87%

Table 3: Runoff rates; 40% climate change added to the calculations for the proposed 1:100 event


10

Climate Change

The design lifetime of a residential site is typically 100 years and an allowance for climate change

should be considered in accordance with published guidance within the NPPF. As such, the ‘upper

end’ allowance 40% climate change allowance has been applied to the drainage and storage

calculations (Table 4).

PEAK RAINFALL INTENSITY ALLOWANCE IN SMALL AND URBAN CATCHMENTS

Applies across all

of England

Total potential change

anticipated for the

‘2020s’ (2015 to 2039)


anticipated for the

‘2050s’ (2040 to 2069)


anticipated for the ‘2080s’

(2070 to 2115)

Upper End 10% 20% 40%

Central 5% 10% 20% Table 4: Peak rainfall intensity allowance in small and urban catchments

Long Term Storage

Long‐term storage is usually required to address the additional runoff caused by the development

compared to the volume that would be contributed from the site in its Greenfield state. The

drainage strategy proposed discharges runoff to the ground, therefore no long‐term storage is

required.

Urban Creep

Urban Creep has not been applied to this site, given that the site is shared between multiple

occupants and external areas are common areas managed and maintained by the developer.

Attenuation Storage

Attenuation storage is needed to temporarily store water during periods when the runoff rates

from the development site exceed the allowable discharge rates from the site.

Rainfall depths for the 1 in 100 years return period plus 40% of CC were produced using Micro

Drainage software to estimate the largest volume and critical storm, for typical storm durations.

The maximum allowable discharge rate into the surface water sewer is 1.00 l/s

Based on the calculations in Appendix 3 a total of 32.5 m3 of water storage is required on site. The

remaining 38m3 can be stored in 50m2, 0.8m deep, geocellular crate storage. At detailed design

some storage could be located under the permeable car park area if required. Final storage

locations and volumes can be provided at detailed design stage. Details of the location is shown in

Appendix 2.

Guidance about proper use, installation and maintenance of any proprietary system must be

provided by the supplier and incorporated into the site proposals at detailed design stage.

4. Design Exceedance

In the event of drainage system failure under extreme rainfall events or blockage, flooding may occur within the site. In the event of the development’s drainage system failure, the runoff flow will be dictated by topography on site and flow paths.

Design of external ground levels will need to be undertaken at detailed design stage.


11

Finished Floor Levels should be 150mm above surrounding finished ground levels where feasible.

This is to mitigate against any potential surface water flows, with external ground levels to be

designed to direct water to the main road areas and away from buildings and thresholds where

feasible. See indicative flow routes on drawing in Appendix 2.

5. Water Quality

Adequate treatment must be delivered to the water runoff to remove pollutants through SuDS devices, which are able to provide pollution mitigation. Pollution Hazards and the SuDS Mitigation have been indexed in the CIRIA 753 ‘The SUDS Manual’.

The Pollution Hazard Indices are summarized in Table – Summary of Pollution Hazard Indices for different Land Use below (reference: Table 26.3.CIRIA SuDS Manual 2015).

POLLUTION HAZARD INDICES FOR DIFFERENT LAND USE CLASSIFICATIONS

LAND USE Pollution

Hazard Level

Total suspended Solids (TSS)

Metals Hydrocarbons

Residential Roofs Very Low 0.2 0.2 0.05

Individual property driveways, residential car parks, low traffic roads

Low 0.5 0.4 0.4

Table 5: Summary of Pollution hazard Indices for different Land Use.

The Mitigation Indices of the proposed SuDS techniques are summarized in the Table 6 ‐ Indicative SuDS Mitigation Indices below. It can be seen the water treatment provided by the Permeable Pavement (the SuDS mechanisms proposed), should be enough to remove the pollutants.

INDICATIVE SuDS MITIGATION INDICES FOR DISCHARGES TO SURFACE WATER

SuDS Component Total suspended Solids (TSS) Metals Hydrocarbons

Permeable Pavement 0.7 0.6 0.7

Geocellular Tank ‐ ‐ ‐

Table 6: Indicative SuDS Mitigation Indices

Runoff from roof areas is considered to generally be uncontaminated. However, to prevent any

potential sediment from impacting on the storage structure, Sediments Traps should be provided

on the outlet to the storage structure to prevent sedimentation, with rodding access provided

either side for cleaning and maintenance.

The contamination risk associated with the proposed development site is considered to be very

low, with sediment traps (for the roof runoff) and permeable paving deemed suitable to mitigate

against the potential contamination risk prior to discharging runoff to the ground.

6. Adoption and Maintenance

All onsite SuDS and drainage systems will be privately maintained. A long‐term maintenance regime should be agreed with the site owners before adoption. In addition to a long‐term maintenance regime, it is recommended that all drainage elements implemented on site should be inspected following the first rainfall event post construction and monthly for the first quarter following construction.


12

Table 7: Proposed Schedule of Maintenance for Below Ground Drainage.

Item Visual

Inspection

Cleanse /

De‐sludge

CCTV

Survey Comments

Surface Water Drainage

System (pipework,

chambers etc.)

5 years 10 years 10 years Cleansing to be carried as

necessary

Gullies/Channels 1 year 1 year N/A Cleansing to be carried as

necessary

Catchpits 1 year As required N/A Cleansing to be carried as

necessary

Permeable Block Paving 1 year

‘Swept’ clean of

debris every 2

years.

N/A

Lift blocks and remove sand

bedding and replace and re‐bed

paving – refer to individual

manufacturers recommendations.

Flow control 1 year As required N/A Cleansing to be carried as

necessary

Geocellular Tanks 1 year As required 5 years

Remove sediment from pre‐

treatment structures (e.g.

Permeable pavement); Inspect

inside of tank for sediment build‐

up and remove as necessary


13

7. Conclusion

This study has been undertaken in accordance with the principles set out in the NPPF and London

Borough of Waltham Forest local policy SuDS guidance. Providing the development adheres to the

conditions advised in this report, the said development proposals can be accommodated without

increasing flood risk within the locality in accordance with objectives set within the NPPF and

published guidance.

The existing site compromises of a residential building and a garage toward the south of the site.

The redline application boundary area is approximately 1110m2 (0.111ha). The existing

hardstanding area associated with the respective buildings and adjacent paths/driveway totals

approximately 160m2.

The development is for the construction of a block of flats to replace an existing dwelling. Following

development, the total hardstanding area of the site would increase to approximately 640m2

(0.074ha).

There are no nearby watercourses to drain into. There are surface water sewers on Mountain Echo

Drive and Mountain Echo Avenue, it is assumed there is an existing connection to the surface water

sewer. There are no invert/depths indicated for the storm sewer in Mount Echo Avenue so levels

of this drain may need confirmation prior to detailed design.

The British Geological Survey (BGS) Geology of Britain Viewer indicates that the bedrock underlying

the site is London Clay Formation - Clay, Silt And Sand. The superficial soil deposits in the wider area have not been recorded on the BGS viewer. Based on the BGS geology information, infiltration

is not considered to be feasible.

A review of the EA flood map for planning (Figure 2) has demonstrated that the site is located in Flood Zone 1 (Low Risk). The EA surface water flooding risk map indicates that the entire redline application boundary is at ‘Low’ risk of flooding.

Based on the calculations in Appendix 3 a total of 32.5 m3 of water storage is required on site. The remaining 38m3 can be stored in 50m2, 0.8m deep, geocellular crate storage. At detailed design some storage could be located under the permeable car park area if required. Final storage locations and volumes can be provided at detailed design stage. Details of the location is shown in Appendix 2.

The flow control for the system is provided through a Hydrobrake or similar vortex flow control device limiting the flows to the minimum practical peak runoff rate of 1l/s (utilising a 55mm orifice plate).

In the event of drainage system failure, extreme rainfall events or blockage, flooding may occur within the site. In this event, it should be ensured water runoff would not impact on the proposed building or neighbouring properties. To mitigate against potential flooding, the building’s finished floor level should be raised 150mm above adjacent external ground levels, if feasible.

The Treatment train of Permeable Paving and Proprietary Treatment Systems ‐ Sediment Traps, are suitable to offer acceptable contamination treatment to runoff prior to being discharged to the ground.


14

The proposals demonstrate that a significant reduction in runoff rates post development can be

achieved via implementation of the development and therefore can provide a betterment both in

respect to flood risk and surface water drainage at the site in accordance with NPPF, the London

Borough of Waltham Forest local policy requirements.

The findings and recommendations of this report are for the use of the client who commissioned

the assessment, and no responsibility or liability can be accepted for the use of the report or its

findings by any other person or for any other purpose.


15

Appendix 1 – Supporting Information

MOUNT ECHO AVENUE

MOUNT ECHO DRIVE

ECHO HEIGHTS

55

62

SEYMO

UR RO

AD34

28

55

53

47

1

9

MO

UN

T ECHO DRIVE

MOUNT ECHO AVENUE

53

No.55 Existing House

No.1 Echo Heights

New Flats Block Gardens

Echo Heights

sightline

1

2

cycl

es

refu

se1

2

3

4

r a m p

Parking

cyclespermeable paving

34 32

(permeable surface)

sightlin

e

30 2826

Communal Gardens

existing trees

(demolished)

retained

(demolished)No.55 Existing Garage

up

cycles

0 20 40

1: 1250

60 80

10 0 10

Scale: Metres

5

1: 200

N

N datedrawn

scale paper size@

drawing no

drawing

projectrev

55 Mount Echo AvenueLondon E4

Block & Site Location Plans

A3

8/2020

SITE LOCATIONPLAN 1:1250

1:200, 1:1250

BLOCK PLAN 1:200

Residential Redevelopment

pB1903 :1A

Proposed


16

Appendix 2 – Preliminary Surface Water Drainage Strategy Layout

r a m p existing treesretained

up

No.55 Existing House(demolished)

No.55 Existing Garage(demolished)

cycles

1

2

3

4 Parking(permeable surface)

1

2

cycl

es

permeable paving

Echo

Heig

htsM

OU

NT

ECHO

DRI

VE

Gardens Flat

s Blo

ckN

ew

Communal Gardens

No.1Echo Heights

53sightline

refu

se

cycles

sightlin

e

SW

SW SW SW SW SW SW SW SW SW SW SW SW

SWSW

SWSW

SWSW

SWSW

SW

SWSW

SW

50SQM GEOCELLULAR CTORAGE 0.8m DEEPOFFERING 22.8 CUBIC M STORAGE

FINAL SHAPE AND LOCATION TO BE CONFIRMED,POTENTIALLY USE PERMEABLE PAVEMENT FOR

STORAGE AT DETAILED DESIGN STAGE TO REDUCECRATE VOLUME

PERMEABLE PAVEMENTAREA AVAILABLE FOR STORAGE IS

APPROX 113sqmFOR COLLECTION AND

TREATMENT OF RUNOFF

SLOTTED PIPE TO COLLECTRUN OFF FROM CAR PARK

LAY NEW CONNECTION TO PUBLICSURFACE WATER SEWER.

ANY NEW CONNECTION TO OFFSITESEWERS TO BE AGREED WITH LOCAL

WATER AUTHORITY.OFFSITE SEWER DEPTH TO BE

CONFIRMED PRIOR TO DETAILEDDESIGN

HYDROBRAKE MANHOLE WITH 55mmOPENING TO LIMIT FLOWS TO 1l/s AS PER

SURFACE WATER DRAINAGE STRATEGY 5601

SW SW

SW

SWSW

SWSW

SWSW

SW

ACO

SW

SW

IMPERMEABLE LINERSURROUND

(1:20)

GEOCELLULAR STORAGE

750m

m M

IN C

OVER

+52.675 TARMAC SURFACE

50mm DEEP 5mm SINGLE SIZED

125

150mm GEN1 BED AND BACKING125x225 HB KERB WITH

CLEAN CRUSHED STONE.

60mm AQUAFLOW BLOCKS

PERMEABLE PAVING(1:20)

600

340mm

375m

m

150mm

EYE BRACKETFOR OPERATINGROPE

CONCRETE SURROUND GRADE GEN3150THK. (SULPHATE RESISTING)

LIFTING EYES INCONCRETE RINGS TO BEPOINTED

PIVOTING BY-PASS DOOROPERATING STEEL ROPE

HYDRO-BRAKE FLOW CONTROL BY HYDROINTERNATIONAL.SEE DRAINAGE LAYOUT FOR TYPE ANDLIMITED FLOW.

INLET PIPE OUTLET PIPE

50mm CONCRETE BLINDINGSURFACE OF JOINTROUGHENED TO PROVIDEKEY

GRADE GEN3 CONCRETE(SULPHATE RESISTING)

OUTLET SPIGOT

NEOPRENE RUBBER GASKET

CONCRETE SURROUNDGRADE GEN3 150THK.(SULPHATE RESISTING)

N.T.S.

PULL HANDLEACCESS TO BE POSITIONED ABOVEBY-PASS DOOR

600

2-4 COURSES SOLID ENGINEERINGBRICKS, PRECAST CONCRETEMASONARY UNITS OR PRECASTCONCRETE COVER FRAME SEATINGRINGS. MORTAR OR APPROVED RESINCOMPOUND TO BE MIN. 40 KN.

'B'REFER TOTABLE 1

PRECAST CONCRETE MANHOLESECTIONS, AND REINFORCED PRECASTCOVER SLAB AND REDUCING SLAB TOBE BEDDED WITH MORTAR,PROPRIETARY BITUMEN, RESIN,MASTIC OR SEALANT STRIPS THATHAVE THE APPROVAL OF THE PCMANUFACTURERS.

520

MANHOLE CONTROL(HYDRODBRAKE) SECTION

TYPE 3 INSPECTION CHAMBER

SW PRIVATE SURFACE WATER DRAIN

PERMEABLE PAVING

OVERLAND FLOW

LEGEND

ATTENUATION SYSTEM

PERFORATED SURFACE WATER DRAIN

ACO CHANNEL DRAIN

1m 2m 3m 4m 5m01:100 @ A1

... ... ...XX.XX.XX##

1. GENERALa. THIS DRAWING IS NOT TO BE SCALED, WORK TO FIGURED DIMENSIONS ONLY,

CONFIRMED ON SITE.b. THIS DRAWING IS TO BE READ IN CONJUNCTION WITH ALL RELEVANT

ARCHITECTURAL DRAWINGS, DETAILED SPECIFICATIONS WHEREAPPLICABLE AND ALL ASSOCIATED DRAWINGS IN THIS SERIES.

c. ANY DISCREPANCY ON THIS DRAWING IS TO BE REPORTED IMMEDIATELY TOTHE PARTNERSHIP FOR CLARIFICATION.

d. THE CONTRACTOR IS RESPONSIBLE FOR ALL TEMPORARY WORKS AND FORTHE STABILITY OF THE WORKS IN PROGRESS.

e. CDM REGULATIONS 2015. ALL CURRENT DRAWINGS AND SPECIFICATIONSMUST BE READ IN CONJUNCTION WITH THE DESIGNER'S HAZARD RISK ANDENVIRONMENT ASSESSMENT RECORD. DESIGN HAS BEEN PRODUCED BASEDON INFORMATION PROVIDED BY THE CLIENT/PRINCIPLE DESIGNERAVAILABLE AT TIME OF ISSUE. CONTRACTOR TO REVIEW DRAWING ANDSPECIFICATION IN CONTEXT WITH THE WIDER SITE AND SPECIFIC SITEINVESTIGATION, CONTAMINATION ASSESSMENT, ASBESTOS SURVEY,ENVIRONMENTAL SURVEY, UXO SURVEY AND ANY OTHER RELEVANTINFORMATION AND MANAGE RISKS RELATING TO THE WORKS OUTLINED INTHE DRAWINGS AND SPECIFICATION. PRINCIPLE CONTRACTOR TO MAKEDESIGNER AND CLIENT AWARE OF SITE SPECIFIC RISKS THAT MAY AFFECTTHE DRAWING AND SPECIFICATION.

f. CDM REGULATIONS 2015. FOR GENERIC MAINTENANCE AND MANAGEMENTRISKS REFER TO CHAPTER 36 OF CIRIA 752 SUDS MANUAL. FORPROPRIETARY SYSTEMS SEE MANUFACTURER'S MANAGEMENT ANDMAINTENANCE DETAILS AND RISK ASSESSMENT WITH REGARDS TOMAINTENANCE OF PROPRIETARY SYSTEMS.

2. CONSTRUCTION NOTEa. THE MAIN CONTRACTOR IS RESPONSIBLE FOR THE DESIGN OF ALL

TEMPORARY WORKS, AND IS ALSO RESPONSIBLE FOR THE SAFEMAINTENANCE AND STABILITY OF EXISTING BUILDINGS AT ALL TIMES.

b. THE MAIN CONTRACTOR IS RESPONSIBLE FOR ALL OCCURRENCES OF GROUNDWATER DURING THE CONSTRUCTION PERIOD.

c. ANY INFORMATION GIVEN REGARDING EXISTING UNDERGROUND SERVICES ISGIVEN IN GOOD FAITH AFTER CONSULTATION WITH THE RELEVANTAUTHORITY, HOWEVER ACCURACY IS NOT CERTAIN. THE MAINCONTRACTOR IS RESPONSIBLE FOR CHECKING ALL INFORMATION ON SITEPRIOR TO WORK COMMENCING AND TAKING DUE CARE AND ATTENTIONWHILST UNDERTAKING THE WORKS.

d. THE CONTRACTOR MUST COMPLY WITH ALL CURRENT LEGISLATION RELATINGTO HEALTH & SAFETY.

e. ALL PRODUCTS SPECIFIED SHALL BE INSTALLED IN STRICT ACCORDANCE WITHTHE MANUFACTURERS RECOMMENDATIONS AND INSTRUCTIONS. IF THEREARE DISCREPANCIES BETWEEN THAT INFORMATION AND THE DETAILS ONANY AMBIENTAL DRAWINGS, THE MANUFACTURERS INSTRUCTIONS MUSTBE USED

3. BELOW GROUND DRAINAGEa. PIPEWORK TO BE UPVC-U PIPES TO BS 4660 : 2000 AND INSPECTION

CHAMBERS TO BS 7158 : 2001.b. ALL ADOPTABLE DRAINAGE TO BE CONSTRUCTED IN ACCORDANCE WITH

'SEWERS FOR ADOPTION' 7TH EDITION AND THE RELEVANT COUNCILDESIGN GUIDE.

c. ALL PRIVATE SURFACE WATER SEWERS TO BE LAID AT 1 IN 100 UNLESSOTHERWISE STATED ON THE DRAWING.

d. ALL PRIVATE FOUL WATER SEWERS TO BE LAID AT 1 IN 40 AT THE HEAD OFPIPE RUNS AND 1 IN 80 ELSEWHERE UNLESS OTHERWISE STATED.

e. ALL PRIVATE FOUL SEWER PIPES TO BE 150MM DIAMETER UNLESSOTHERWISE STATED ON THE DRAWING. ALL PRIVATE SURFACE WATERSEWER PIPES TO BE 100MM DIAMETER FROM DOWNPIPES AND 150MMDIAMETER ELSEWHERE UNLESS OTHERWISE STATED ON THE DRAWING.

f. ALLOW FOR RODDING ACCESS ABOVE GROUND WHERE RAINWATERDOWNPIPES DO NOT HAVE A DIRECT CONNECTION TO AN INSPECTIONCHAMBER. EXISTING SEWER PIPE TO BE RE-USED TO BE SURVEYED ANDLEVELLED PRIOR TO COMMENCEMENT OF THE DRAINAGE WORKS ANDREFURBISHED IF NECESSARY.

g. CONNECTIONS TO AN ADOPTED SEWER ONLY TO BE MADE FOLLOWINGAPPROVAL FROM THE RELEVANT ADOPTING AUTHORITY.

h. ALL DRAINS, SEWER PIPES AND MANHOLES TO BE CLEANED AND TESTED FORWATER TIGHTNESS ON COMPLETION OF CONSTRUCTION.

4. MANHOLE COVERS AND FRAMESa. MANHOLE COVERS TO BE CLASS D400 IN HIGHWAYS, CLASS B125 IN

FOOTWAYS AND VERGES, CLASS A15 IN NON-TRAFFICKED AREAS.b. MANHOLE COVER AND FRAME TO BE BEDDED AND SURROUNDED IN 1:3

MORTAR.

Drawing No. Revision

Drawing Scale:

Drawn by: Date:

Drawing

Project

Client

Draw

ing

No:

REV DATE DESCRIPTIONBY CKD APPD

PRELIMINARY DRAWINGFOR INFORMATION ONLY. NOT FOR CONSTRUCTION.

BLUEYONDER

55 MOUNTAIN ECHO AVENUELONDON E4 7JX

SITE LAYOUTSTORM DRAINAGE STRATEGY

5601 - DR01

TV JUL - 2020

-

C:\U

sers

\305

223\

Box\

WAT

-DW

-AEA

Gen

eral

\PRO

JECT

S\56

01_S

quire

s_M

t.Ech

o Av

enue

\Pla

ns\A

mbi

enta

l\560

1 DR

01.d

wg

THAMES WATER SEWERRECORD PLAN EXTRACT

AutoCAD SHX Text

GEOCELLULAR CRATE STORAGE WRAPPED IN GEOTEXTILE TO MANUFACTURER'S INSTALLATION GUIDELINES. FOR SIZE SEE DRAWINGS 5601 DR01

AutoCAD SHX Text

COMPACTED AS-DUG BACKFILL

AutoCAD SHX Text

150mm LINK PIPE

AutoCAD SHX Text

TERRAM 1000 GEOTEXTILE SURROUND TO PIPE

AutoCAD SHX Text

150mm UPPER SUB-BASE 20-5mm STONE

AutoCAD SHX Text

WELDED IMPERMEABLE MEMBRANE

AutoCAD SHX Text

150mm SLOTTED PIPE

AutoCAD SHX Text

50mm VENT PIPE


17

Appendix 3 – Calculations

��

�

��

��

��

�� !"�

�� #��$�%&'

()*+,-+*.)/0

#�� 1�2�3%34�5

#��6� �� 11$$4�7

8 �� 6��

9�� "��!6��6 ��:;�� 6��

��"��9��<=��>��13�?��1>@�=�� A�� %�>�?��=��1�@��

� ��B�� A��?A��=��1�@��8 ��6��

��

� ��6�� 6��

;�� $�%�32�>�%

A�� ! 6��1��>

CDEFGG,+0*)H.*)FE,.IIJF.KL MN1�$

()*+,KL.J.K*+J)0*)K0

8��? �@��111

O+*LFPF/FQR

S �� T;��!!;

�T;�� UM#��9�

(F)/,KL.J.K*+J)0*)K0A��

�UM#��9��$ $

NU�8��5�! 5�!

�T;��T;NU�8��$% ��$%

VRPJF/FQ)K./,KL.J.K*+J)0*)K0A��

�!!;�?��@�2�� 2��

N��6��6��2 2

�� "��1��

�� "��>�� > ��>

�� "��1�� >�13 >�13

�� "�� >�%$ >�%$

WF*+0

XYZ,[0,\ ,],̂_̀,/a0aL.b

7 ��S ��c�� 6�� 6��

��

X̂Z,dJ+,G/Fe,J.*+0,],f_̀,/a0b

7 �� 6��

� ��6��"�6��

��9��#��

� ��6�� 6��99��9��6�

��

XgZ,[0,(hCa(hCVi(j,k,̀_gb

7 ��6�� "�� 6 ��

��"�� 6�� 9��

��9��

lJ++EG)+/P,JDEFGG,J.*+0A��

S �?��@��$2 ��$2

1��1��?��@��$ ��$

1��>��?��@� 1��% 1��%

1��1��?��@� 1�$� 1�$�

1��?��@� 1�%$ 1�%$8 ��9��9�� 6�� 6�� "��9��N;�7��6��"�� 8 �� m�� no�� A��

��6��=�� B��B�� 8 �� 9 �� 6�� 8 ��

��9�� 5��9��N;�7��6��=�� "��!6��=��N=�N�� 6�� 6��

�9�� 6��

p!;

qdC

p!;

p!;

Ambiental Environmental File: 5601 - Calcs (Brown eld).pfdNetwork: Storm NetworkMark Naumann20-Aug-20

Page 15601_Squires_Mt.Echo Avenuebrown eld calcs

Flow+ v9.1 Copyright © 1988-2020 Causeway So ware Solu ons Limited

Design Se ngs

Rainfall MethodologyReturn Period (years)

Addi onal Flow (%)FSR Region

M5-60 (mm)Ra o-R

CVTime of Entry (mins)

FSR1001England and Wales20.0000.4000.7504.00

Maximum Time of Concentra on (mins)Maximum Rainfall (mm/hr)

Minimum Velocity (m/s)Connec on Type

Minimum Backdrop Height (m)Preferred Cover Depth (m)

Include Intermediate GroundEnforce best prac ce design rules

30.0050.01.00Level So ts0.6000.900✓✓

Nodes

Name Area(ha)

T of E(mins)

CoverLevel(m)

Diameter(mm)

Eas ng(m)

Northing(m)

Depth(m)

1Drained areaGeocellular storage

0.016 4.00 10.00010.000

12001200

-78.01912.034

43.57845.612

1.0001.062

Links (Input)

Name USNode

DSNode

Length(m)

ks (mm) /n

US IL(m)

DS IL(m)

Fall(m)

Slope(1:X)

Dia(mm)

T of C(mins)

Rain(mm/hr)

1.000 Drained area Geocellular storage 5.000 0.600 9.000 8.938 0.062 80.0 100 4.10 50.0

Simula on Se ngs

Rainfall MethodologyFSR Region

M5-60 (mm)Ra o-R

Summer CVWinter CV

FSREngland and Wales20.0000.4000.7500.840

Analysis SpeedSkip Steady State

Drain Down Time (mins)Addi onal Storage (m³/ha)

Check Discharge Rate(s)Check Discharge Volume

Detailedx14400.0xx

Storm Dura ons15 30 60 120 180 240 360 480 600 720 960 1440

Return Period(years)

Climate Change(CC %)

Addi onal Area(A %)

Addi onal Flow(Q %)

130

100

000

000

000




Results for 1 year Cri cal Storm Dura on. Lowest mass balance: 100.00%

Node Event USNode

Peak(mins)

Level(m)

Depth(m)

In ow(l/s)

NodeVol (m³)

Flood(m³)

Status

Link Event(Upstream Depth)

USNode

Link DSNode

Ou low(l/s)

Velocity(m/s)

Flow/Cap LinkVol (m³)

DischargeVol (m³)

115 minute winter Drained area 10 9.044 0.044 2.4 0.0498 0.0000 OK

15 minute winter Drained area 1.000 Geocellular storage 2.4 0.754 0.355 0.0159 1.0

15 minute winter Geocellular storage 10 8.979 0.041 2.4 0.0000 0.0000 OK





Node Event USNode

Peak(mins)

Level(m)

Depth(m)

In ow(l/s)

NodeVol (m³)

Flood(m³)

Status


USNode

Link DSNode

Ou low(l/s)

Velocity(m/s)


DischargeVol (m³)








Node Event USNode

Peak(mins)

Level(m)

Depth(m)

In ow(l/s)

NodeVol (m³)

Flood(m³)

Status


USNode

Link DSNode

Ou low(l/s)

Velocity(m/s)


DischargeVol (m³)

115 minute winter Drained area 10 9.127 0.127 7.6 0.1437 0.0000 SURCHARGED



Ambiental Environmental File: 5601 - Calcs.pfdNetwork: Storm NetworkMark Naumann19/08/2020

Page 15601_Squires_Mt.Echo AvenueProposed calcs


Design Se ngs

Rainfall MethodologyReturn Period (years)

Addi onal Flow (%)FSR Region

M5-60 (mm)Ra o-R

CVTime of Entry (mins)

FSR10040England and Wales20.0000.4000.7504.00

Maximum Time of Concentra on (mins)Maximum Rainfall (mm/hr)

Minimum Velocity (m/s)Connec on Type

Minimum Backdrop Height (m)Preferred Cover Depth (m)

Include Intermediate GroundEnforce best prac ce design rules

30.0050.01.00Level So ts0.6000.900✓✓

Nodes

Name Area(ha)

T of E(mins)

CoverLevel(m)

Diameter(mm)

Eas ng(m)

Northing(m)

Depth(m)

1Drained areaGeocellular storage4

0.065 4.00 10.00010.00010.000

1200

1200

-78.32612.034

112.753

43.88545.61246.763

1.0501.1121.174

Links (Input)

Name USNode

DSNode

Length(m)

ks (mm) /n

US IL(m)

DS IL(m)

Fall(m)

Slope(1:X)

Dia(mm)

T of C(mins)

Rain(mm/hr)

1.0001.001

Drained areaGeocellular storage

Geocellular storage4

5.0005.000

0.6000.600

8.9508.888

8.8888.826

0.0620.062

80.080.0

150150

4.074.15

50.050.0

Simula on Se ngs

Rainfall MethodologyFSR Region

M5-60 (mm)Ra o-R

FSREngland and Wales20.0000.400

Summer CVWinter CV

Analysis SpeedSkip Steady State

0.7500.840Detailedx

Drain Down Time (mins)Addi onal Storage (m³/ha)

Check Discharge Rate(s)Check Discharge Volume

14400.0xx

Storm Dura ons15 30 60 120 180 240 360 480 600 720 960 1440






Addi onal Area(A %)

Addi onal Flow(Q %)



Addi onal Area(A %)

Addi onal Flow(Q %)

130

4040

00

00

100 40 0 0

Node Geocellular storage Online Hydro-Brake® Control

Flap ValveDownstream Link

Replaces Downstream LinkInvert Level (m)

Design Depth (m)Design Flow (l/s)

x1.001✓8.8880.8001.0

Objec veSump Available

Product NumberMin Outlet Diameter (m)

Min Node Diameter (mm)

(HE) Minimise upstream storage✓CTL-SHE-0049-1000-0800-10000.0751200

Node Geocellular storage Depth/Area Storage Structure

Base Inf Coe cient (m/hr)Side Inf Coe cient (m/hr)

0.000000.00000

Safety FactorPorosity

2.00.95

Invert Level (m)Time to half empty (mins)

8.888280

Depth(m)

Area(m²)

Inf Area(m²)

Depth(m)

Area(m²)

Inf Area(m²)

Depth(m)

Area(m²)

Inf Area(m²)

Depth(m)

Area(m²)

Inf Area(m²)

0.000 50.0 0.0 0.400 50.0 0.0 0.800 50.0 0.0 0.801 0.0 0.0




Results for 1 year +40% CC Cri cal Storm Dura on. Lowest mass balance: 100.00%

Node Event USNode

Peak(mins)

Level(m)

Depth(m)

In ow(l/s)

NodeVol (m³)

Flood(m³)

Status


USNode

Link DSNode

Ou low(l/s)

Velocity(m/s)


DischargeVol (m³)


120 minute winter Drained area 1.000 Geocellular storage 4.2 0.966 0.211 0.0775

120 minute winter Geocellular storage 94 9.056 0.168 4.2 8.0028 0.0000 SURCHARGED

120 minute winter Geocellular storage Hydro-Brake® 4 0.9 12.1

15 minute summer 4 1 8.826 0.000 0.8 0.0000 0.0000 OK





Node Event USNode

Peak(mins)

Level(m)

Depth(m)

In ow(l/s)

NodeVol (m³)

Flood(m³)

Status


USNode

Link DSNode

Ou low(l/s)

Velocity(m/s)


DischargeVol (m³)





15 minute summer 4 1 8.826 0.000 0.9 0.0000 0.0000 OK


18

Appendix 4 – CCTV report

Ref C0013118 Date 03/08/2020 Heritage Estate Group Ltd 55 Mount Echo Avenue London E4 7JX Dear Sir/Madam 1. DESCRIPTION OF PROPERTY Residential Property 2. DRAINAGE SYSTEM The pipework surveyed is a foul drainage system, accessible by Inspection Chambers. The pipework is circular, 100mm in diameter and both pvc & vitrified clay materials. Further specific variations may be in the report content. 3. SHARED The sections within the property boundary are private; therefore, the responsibility of the site owner to maintain. 4. CIRCUMSTANCES

General investigation Works.

5. SUMMARY The defects noted in the attached report. 6. Quotation and Specification of Repairs To attend the above site and provide crew, materials, labour and plant to: ‐ Set up barrier protection Repair 1) – Sections 1 & 2 Excavate, remove and replace the defective pipework and realign the new installation to maximise flow. We will be pleased to carry out the above works for the sum of £2185.00 + VAT To make‐good, the above‐described works assuming no further problems found

The pipework will be tested and using CCTV to ensure maximum efficiency has been achieved and left in full working order and made good to BS EN 752. All debris removed from the site, and the site will be in a clean and clear condition on completion. 7. COST SAVINGS The proposed repair methods are specially selected, as the most cost‐effective method and expedient to rectify the defects noted. 8. GUARANTEE Please note that all repair works proposed are guaranteed for up to 5 years for repairs, and our guarantee does not affect your statutory rights. Due to the nature of working underground, it is not possible to state that there will be no further damage discovered. Once the repairs commence, if this occurs, we will make all efforts to mitigate the costs and seek authority through the proper channels before carrying out additional repairs. Please ensure that appropriate access to water and electricity provided on‐site to complete the repair (the engineer will confirm these details with you). If you require more information or wish to discuss this matter, please contact us. Yours sincerely Happy Drains Ltd

55

MOUNT ECHO AV

MO

UN

T E

CH

O D

RIV

E

MH1

MH2(BURIED)

MH3

REAR ELEVATION

SURVEY CARRIED OUT AS A STUDY FOR FUTURE CONSTRUCTION OF FLATSONLY THE PIPELINES SHOWN WERE REQUIRED TO BE SURVEYED

Happy Drains LtdUnit 12A chalex Ind Est, Southwick

Tel. 0800 849 [email protected]

Section Inspection - 22/07/2020 - MH1XSection Inspection Date Client's Ref Contractor's Ref Surface Type PLR

1 1 22. July 2020 C0013118 C0013118 Paving Slabs MH1X

Operator Vehicle Camera Temperature Pre Cleaned WeatherPE62 KTC SOLO PRO 2 Yes No rain or snow

Town or Village: London Inspection Direction: Downstream US MH: MH1

Road: 55 Mount Echo Av Use: Combined US Depth: 0.55 m

Location: Gardens (private) Total Length: 8.04 m DS MH: MH2 BURIED

Post Code: E4 7JX DS Depth: 0.85 m

Inspection Purpose:Routine inspection Pipe Shape: Circular

Surface Defects: Height / Width: 100 / 100mm

Lining Type: None Pipe Material: Polyvinyl Chloride

Lining Material: Standard: WRC MSCC5 Light

Comments:

Recommendations:

Scale: 1:67 Position [m] Code Observation Grade

0.00 MH Start manhole, MH1

0.06 MC Pipe material changes, to vitrified clay A

0.59 CC Circumferential crack from 11 o'clock to 10 o'clock A

A

4.72 JDL Large displaced joint C

A

5.45 JN Junction at 12 o'clock, diameter:100mm A

5.57 FC Circumferential fracture from 12 o'clock to 12o'clock

B

7.04 RJ Roots at joint B

8.04 MHF Finish manhole, MH2 BURIED, the pipe isunserviceable

55 Mount Echo Avenue - London - E4 7JX 1

MH1

MH2 BURIED

MH @ 0.00 m

MC @ 0.06 m

CC @ 0.59 m

JDL @ 4.72 m

MC @ 4.85 m



Section Inspection - 22/07/2020 - MH1XSection Inspection Date Client's Ref Contractor's Ref Surface Type PLR

1 1 22. July 2020 C0013118 C0013118 Paving Slabs MH1X

Operator Vehicle Camera Temperature Pre Cleaned WeatherPE62 KTC SOLO PRO 2 Yes No rain or snow

Pipe Condition Grade: C Service Condition: Not Serviceable

Structural Defects Construction FeaturesService & Operational Observations Miscellaneous Features


JN @ 5.45 m FC @ 5.57 m RJ @ 7.04 m MHF @ 8.04 m



Section Inspection - 22/07/2020 - MH2 BURIEDXSection Inspection Date Client's Ref Contractor's Ref Surface Type PLR

2 1 22. July 2020 C0013118 C0013118 Paving Slabs MH2 BURIEDX

Operator Vehicle Camera Temperature Pre Cleaned WeatherROB PE62 KTC SOLO PRO 2 Yes No rain or snow

Town or Village: London Inspection Direction: Downstream US MH: MH2 BURIED

Road: 55 Mount Echo Av Use: Combined US Depth: 0.85 m

Location: Gardens (private) Total Length: 3.11 m DS MH: MH3

Post Code: E4 7JX DS Depth: 1.00m

Inspection Purpose:Routine inspection Pipe Shape: Circular

Surface Defects: Height / Width: 100 / 100mm

Lining Type: None Pipe Material: Vitrified Clay

Lining Material: None Standard: WRC MSCC5 Light

Comments:

Recommendations:

Scale: 1:50 Position [m] Code Observation Grade

0.00 MH Start manhole, MH2 BURIED

1.05 R Roots B

2.27 RJ Roots at joint B

3.11 MHF Finish manhole, MH3, the pipe is unserviceable

Pipe Condition Grade: B Service Condition: Not Serviceable

Structural Defects Construction FeaturesService & Operational Observations Miscellaneous Features


MH2 BURIED

MH3

MH @ 0.00 m

R @ 1.05 m

RJ @ 2.27 m

MHF @ 3.11 m

Surface Water Drainage Strategy (SWDS) 5601

Documents

Transcript of Surface Water Drainage Strategy (SWDS) 5601