Work Term Report 2: Storm Sewer Design for Road Reconstruction
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Transcript of RR-170 - Storm Sewer Design - State of · PDF fileFollowing is the procedure to be used in the...
OFFICE MEMORANDUM
>~ ~
MICHIGAN
DEPARTMENT OF STATE HIGHWAYS
G. J. Fellows Engineer of Design
From, Max N. Clyde Engineer of Design
December 14, 1967
Subject, Storm Sewer Design Program
In accordance with your conversation with J. V. Murray, we are transmitting the originals of the Storm Sewer Design Program. Please prepare and distribute copies of the program to the interested and affected parties to insure uniformity in storm sewer design throughout the Department.
Upon completion, please return the originals to the Utility Design Section.
MAX N. CLYDE
JEngine~ of Design
r/'1/. )1~ . V. MURRAY
Design Supervising Engineer
DD/AJI/gp
STORM SEWER DESIGN
Following is the procedure to be used in the design of storm
sewer systems for highway drainage. This procedure incorporates
several changes in Department policy on sewer design.
changes are:
The major
1. All storm sewers will be designed on a full flowing
basis.
2. Storm sewer design for depressed freeways, using a 50
year storm frequency, will be based upon the sewer flowing under
a head with the hydraulic gradient being a minimum of 1 foot below
gutter grade. A further restriction on the use of this method
provides that the sewer must have an independent outlet.
3. Sewers will be designed with a limiting maximum velocity
of 10 fps with a normal maximum of 8 fps. In extreme cases,
velocities in excess of 10 fps may be tolerated, however; the
designer should obtain the approval of the Utility Design Section
before using higher velocities.
1
1. General
The MDSH uses the rational method for the design of all storm
sewers. The rational method translates rainfall into runoff by
the formula Q = CIA in which:
a. Q is the maximum rate of runoff expressed in cubic feet
per second (CFS),
b ~ "C" is a runoff coefficient which is an estimate of the
ratio of the maximum rate of runoff to the average rate of rainfall
on the area during the time of concentration.
c. "I" is the average rainfall intensity, in inches per
hour, for the period of maximum rainfall having a duration equal
to the time of concentration.
d. A is the drainage area, in acres, tributary to the
point under design.
2. Runoff Coefficient "C"
As the rational method uses average rainfall intensities
prevailing over the time of concentration, which bear no relation
to storm pattern, the use of average "C" values has proven an
acceptable tool in sewer design.
The Department considers the runoff coefficient to be largely
dependent on the percentage of imperviousness of the area under
consideration. Figure 1 indicates the "C" factors to be used for
varying degrees of imperviousness from 1% to 100%.
Following is a list of suggested "C" values for the types
of surface commonly found in the design of highway drainage
systems.
2
Type of Surface % Impervious "C" Value
Pavement and Bituminous Shoulder 100 0.80
1 on 2 Slopes 70 0.60
Flat Unpaved Areas-Heavy Soils 30 0.28
Flat Unpaved Areas-Sandy Soils 10 0.10
Residential Areas 30-60 . 3 to . 5
Commercial Areas 60-100 . 5 to . 8
It is often desirable to develop a weighted "C" factor for
an area with several types of surface. Following is an example
demonstrating this technique as applied to a typical highway cross
section.
ROW Width
Pavement
Sidewalks
Flat Grassed Area (Clay Soil)
100Ft.
60 Ft.
12 Ft.
28 Ft.
60 X .8 = 48.0
12 X • 8 9 • 6
28 X .28 7.8
65.4 -!- 100 .65 weighted "C" value
3. Rainfall
a. Frequency
All highway storm sewers are to be designed for storms
having a 10 year frequency except that a 50 year frequency
storm shall be used at underpasses or other depressed road
ways on the interstate system, and trunklines built to
3
a. Frequency cont.
interstate standards, where ponded water can only be removed
through the storm drain system.
b. Intensity Duration Curves
The rainfall intensity duration curves in Figures 2
through 5 are from U.S. Weather Bureau Technical Paper No. 25.
The localities to which these curves apply are shown in
Figure 6. Table 1 is developed from these curves and gives
the rainfall intensity directly for times between 10 minutes
and 4 hours for the four zones and return periods of 10 and
50 years.
c~ Time of Concentration
The time required for the maximum rate of runoff to
develop is known as the time of concentration. Generally,
it is the time required for a drop of water to flow from the
most remote part of the drainage area to the point under
design. It consists of two parts; the initial or inlet
time and the time of flow in the sewer.
The time of flow in the sewer can be closely estimated from
the hydraulic properties of the sewer. Average flowing-full
velocities expected at the prevailing sewer slope or the slope of
the hydraulic grade line are to be used.
The initial or inlet time must be estimated by the designer.
Past experience has indicated a 15 minute initial time to be
adequate for the design of most highway sewers. However, the
steep grades associated with single sag depressions tend to
produce more rapid runoff. If construction of a pumphouse is
contemplated, at such a location the use of a 10 minute initial
time is warranted. Where multiple sags drain to a common pumphouse
4
a 15 minute initial time is again adequate.
Some circumstances, as when an open drainage system is to
outlet into a proposed storm sewer, may require special study to
determine the initial time.
4. Drainage Area
The area tributary to any point under consideration in a
storm sewer system must be determined. It can be measured
accurately and is the only element of the rational formula
subject to precise determination.
The Department's storm sewers are normally designed to
accommodate the runoff from highway right of way only. However,
in keeping with the Department's "Drainage Policy and Guide,"
allowances should be made to accommodate the surface drainage of
those areas outside the right of way, which slope naturally
towards the roadway, in the condition of imperviousness in effect
at the time of design.
5. Velocities
Generally, design velocities should satisfy the following
conditions:
Min.
Desirable Min.
Max.
Desirable Max.
Velocity
Velocity
Velocity
Velocity
3 fps
4 fps
10 fps
8 fps
When the design is based on a hydraulic grade line the
physical grade of the sewer does not determine the design velocity.
5
Care should be exercised therefore, to assure that the physical
grade of the sewer is such as to provide reasonable self cleaning
velocities atflows less than the design storm.
The following table lists the minimum construction grades to
be used for various sizes of circular concrete pipe storm sewers.
Pipe Size Grade % Pipe Size Grade %
12 0.48 54 0.09
15 0.36 60 0.09
18 0. 2 8 66 0.08
21 0.22 72 0.08
24 0.17 78 0.08
27 0.16 84 0.07
30 0.15 90 0.07
33 0.14 96 0.07
36 0.12 102 0.06
42 0.12 108 0.06
48 0.10 120 0.06
6. Storm Sewer Design Procedure
?allowing is an outline of a typical procedure for the design
of a storm sewer:
1. Obtain prints showing the proposed highway construction.
2. Locate the manhole and inlets on the plan portion of the
prints. (See Sections 5.148 and 5.152 of the Highway Survey and
Design Manual for typical structure spacing)
3. Number the above structures.
4. Determine the area draining to each manhole or inlet and
compute its weighted "C" value.
6
5. Enter the above information on the tabulation sheet.
6. Sketch the desired sewer grade or hydraulic gradient on
the profile sheet and calculate its approximate slope.
7. Obtain the rainfall intensity from Table 1 for the
appropriate initial time.
8. Compute the runoff (Q) for the uppermost structure by
multiplying the weighted "C" factor x intensity x area (CIA).
9. Enter the nomograph in either Figure 7 or 8 with the
above Q and select a sewer size that will accommodate this flow
when flowing full at a grade approximating the slope of the
hydraulic gradeline.
10. Determine the velocity of flow from the nomograph
interpolating between tbe lines of equal velocity as required.
11. Compute the flow time in the sewer from the first to
the second manhole. Add this value to the initial time to obtain
the time of concentration for the second manhole.
12. Add the acreage draining to the second structure to that
of the first and determine the weighted "C" value for the
accumulated area.
13. Compute the estimated runoff at the second structure
using the accumulated area, its weighted "C" factor and the
rainfall intensity corresponding to the new time of concentration.
14. Select a pipe size as in 9 above.
15. Repeat steps 10 through 14 to determine sewer sizes at
the suceeding structures.
Upon completion of the above design adjustments of the H.G.L.
and sewer sizes may be required to obtain the most economical
system consistant with good sewer design practices.
7
7. Estimating Runoff
On occasion the designer may be required to make a preliminary
estimate of the storm water runoff to be discharged to an existing
sewer or to be pumped from a depressed section.
The following procedure is suggested:
1. Assume an average sewer velocity of 5 fps or 300 feet
per minute.
2. Estimate the time of concentration:
Initial Time + L 300
Where L is the length of the approach sewer. (Note:
Where two approach sewers are involved use the longer sewer to
estimate the time of concentration).
3. Determine the total drainage area and its weighted "C"
value.
4. Obtain the rainfall intensity from Table 1 for the
estimated time of concentration.
5. Multiply the total drainage area by the weighted "C"
value and the rainfall intensity to obtain the estimated runoff.
8
FIGURE I
MICHI~AN DEPARTMENT or STATE HI GHWAVS 0 A T A e E N T E R
TABLE OP RUNOFf COEI"I"'eiENTS CTO BE USED WITH 5EWER DESIGN PROGRAM 0401'!0)
PCT RUNDf"f peT RlJNOf"f" PCT RuNorr IMPERV COEFF C IMPERV COEFF C !MPERV cour e
1 • 0.0!3'5 41. 0' 37'50 13 I , (),61'7'2 2. 0,0233 42, 0,3833 82, 0,6840 3, 0,0330 43. 0,3915 83, 0,6908 4, Oo0427 411. (),3997 84, (),691''5 5, 0,0523 45, 0,4079 85, (),'1'(1112 6, 0.0619 46, 0,4160 86, 0,1'108 .,, o.o/'15 47. 0.4241 87, (), 7'174 a, 0,01'110 48. 0,4321 88, 0,1'?40 9, 0,0905 49, 0,4402 89, 0,7305
10. 0,1000 so. 0,4461 90, 0,131'0
11. 0.1094 '51. 0,4561 91. 0,'1'435 !2, 0.1188 52, 0,4640 92, 0,'1'1199 13' 0,1282 53. 0.47'19 93, o,7'163 111. 0.137'5 '54, 0,41'97' 911, (),1',,_., 15o 0,1468 55, 0,481'5 95, o,7690 16, Ool560 56, 0,4953 96, Oo11'53 17, 0,1652 57. 0.5030 97, 0.1'1115 18. 0,17'44 58, 0,5107 98, o, 7'1lH 19, 0' lE135 59. 0.5183 99, (),1'939 20, 0' 1926 60, 0,5259 100, o,aooo
21. 0,2016 61' 0,5335 22, 0.2107 112, 0,'5410 23, 0.2196 113, 0,5465 24, Oo2286 1\4, 0,5560 25, 0.2375 1\5, 0,5634 26, 0.2464 66, 0,5708 2'1', 0,2552 117, 0.51'8:?. 28, 0.2640 68, (),5855 29, Oo21'28 1\9, 0.5928 30, 0,21115 '1'0, 0,6000
31. 0,2902 7! ' 0,601'2 32. 0.2988 '1'2. Oo<H44 33, 0,307/i 73, 0.6215 34, 0,3160 74, Oo6286 35, 0,324') 75, 0,6356 36, 0,3330 76, 0,6427 3'/', 0,341"1 17, 0.6496 31!, (),31!99 '1'8, 0' 6566 39, 0,3563 7'9, (),6635 40. (),366'1' f\Q, o,6T04
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FIGURE 2
ZONE I
RAINFALL INTENSITY -DURATION CURVE
T -NOY£- = FR£(J(J£NCY ANA LYSIS BY M£YHO!J OF =
EXT REM£ VALli£, AFTER GIIM!II£L -:::: -:::: --
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15 20 30 40 50 60 2 4 5 6 li 10 12 11011115 I\IIMIITES
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FIGURE 3
ZONE 2
RAINFA.LL INTENSITY- DURATION CURVE
. -NOT£- =
FREQUENCY ANALYSIS BY METHOIJ OF = EXTREME VALUES, AFTER GUMBEL
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HOURS MINUH'S OIIRATION
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FIGURE 4
ZONE 3
RAINFALL INTENSITY- DURATION CURVE 1!.0 .0
i!Ul ~
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FIGURE 5
ZONE 4
RAINFALL INTENSITY- DURATION CURVE
._ -NOT£ - ::
FR!IC/U!INCY ANALYSIS BY METHOO OF : EXTREME VALUE, liFTER GUMlJ!IL
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10 15 20 30 40 50 60 2 4 5 6 8 10 12 MINUTES OURI\TION
HOURS
FIGURE 7
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15
FIGURE 8
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TABLE 1
'0!CHIGA'I flEPARTMf"NT OF <;TATE HIGHWAYS
RA TNF"ALL I~ITENS! iY 9 D!IRATION TARLF <TD BE USEfl WITH SEWFR DESIGN PROGRAt-A ll40Afl)
T!ME 70'1( 70NE ;> ZONE ~ 70NE 4 TN
M!NIITES )0 9 VR so~vR !O~VR 'iO~vR tn~vR sn~vR )r'lwYR 50 9 YR
)('),() s . :n 7,08 l!.'ifl '5,98 3,78 /j. 9 8 ~.91'> '5,;>3 1 (J .1 5,2'5 7,05 4,54 'i,CJS 3,7(> 1!,9'5 3.94 "·21 )('),2 '5,22 7,02 4,5! '5,93 3,74 4, CJ:l 3,93 '!.19 111 • ~ 5,20 6,99 4,4C) 5,90 3.72 /j' 9 0 3,91 'l' 1 6 )(1,4 5, l A 6,97 4,47 5,1\7 3,70 4,1'\A 3,89 5. 1 4 Hl, 5 ~ & 1" 6,94 4,4'\ '5,85 3,68 lj,l'\'5 3,R7 'i.)2
111,6 5. 14 1\,91 4' 4 1 5,R2 3,61\ 4,A'l 3,811 5.10 10,7 5' 1 2 6,88 4 '4 1. 'i.Ro 3,65 4 • ill 3,84 'i,07 1fl.11 s • 1 () 6,86 4,411 '5,77 3,63 4,7f', 3,8::> o;,os 1(),9 5.08 6.1'13 4,3R S,?'i 3' 6 j 4,7f, 3, R 1 ';,03 11 '0 5,06 6,80 4,31'> '1,7;> 3,59 4,74 3,7<1 5,01
11.1 5,04 6,78 4,34 5,70 3,58 4' 71 3,7R 4,99 11 '2 5,02 6,75 4,1::> 'S,Ail 3,56 4,<'>9 3,7A 1!. 9 7 11 ,3 5,Q() 6,73 4 ' l f1 "i,A5 3.54 4 ' 1\7 3,74 4,95 1 1 ' 4 4,98 6,70 4,;>R 5,<'>3 3' 53 4,65 3' 7 ~ 4,93 1 1 ' 'i 4,9fl 6,68 411~7' "\,61 3.51 lj • "'3 3' 7 1 4,91
11 '6 4,94 6,65 4,;>'i 'i,S8 3,49 /j' "'0 3,711 11, R 9 1 1 ' 7 4,'12 6,63 4,;:>1 '5,'i6 3.48 4,';8 3,6R 4,87 1 I , 11 4,90 6,61 4 ' ::> 1 5,54 3,46 4,'\A 3,67 4,115 1 I , 9 4 .tlA 6,58 ,,;>n '5,'52 3.4'i 4,'i4 :!,65 4,f',3 1?.0 II, A 7 6,56 4, 1 R '5,119 3,43 llo'52 3,1\4 4, A 1
12.1 4,85 6,53 4. 1"' 'i,47 3,42 i.l,'i() 3 'I'>' 4,79 1?. 2 4,83 6,51 4 • \ 'i '5,45 3.40 4,4B 3 '6 1 4,77 1 ;>. 3 4,81 6,49 4' 1' '\,43 3.3'1 4,41\ 3,6(1 4,76 1?.4 4,79 6,47 4' 1? "io41 3.3 7 4' 4 4 3,5!'\ 4,74 12.5 4,7/l 6.44 4.1(} "i,39 3,36 4.4? 3 '57 4,72
1:>,1> 4.76 6,42 4,0'1 5 ' 'l 7 3,34 /j' 4 0 3,56 4,70 \?,7 4.74 6,40 4.01' '5,15 3, :n 4' 3 8 3,54 4,69 1?,8 4. 73 11,38 4,0'\ 5, ''13 3.31 I!' 'H 3 ''i i 4,67 12,9 4,71 6' 3 6 4,04 'i,1j 3,30 4. ::15 3 ''i? 4,65
1 '' 0 4.69 6,34 4.0? 5,;>9 3.29 IJ,j:l 3.50 /j '6 3
1 '.1 4,6fl 6,31 4,01 '5,?7 3,27 /j ' 3 1 3,4'l 4.62 1 3'? 4,6<'> 6,29 3,90 '3,;>5 3,?6 4,;>9 3,41'1 lj '6 0 l 1' 3 4,65 6,27 3,9A '5,?3 3.25 4,;:>7 3.46 4,58 1 3. 4 4,63 6,25 3,91'. "·'1 3.23 4,?6 3.4'1 4.57 13o'i 4,61 6.23 3,9'i 5' 1 9 3.22 /j' 2 4 3' 411 4,'i5
13,1'> 4,60 1\,21 3.9~ 5' 1 7 3.2! 4,;>:;> 3' 4 1 4,53 jj,7 4,')8 I) ' 1 9 3,9? "i,j6 3.!9 II , ? 1 3,4::> 4,52 1 'I ' 8 4.57 6.17 3,90 5.!4 3,jll 4' 1 9 J,4fl 4,50 13.9 4,55 1:>,[5 3,8'l 5.12 3.17 4,)7 3,39 /j' 4 9
Tl>.1E INTERVAL ON THIS SHEET = () • 1 MINUTE 17
TABLE 2
~I CHI GMI !'IFPART~FNT OF STATF HIGHWAYS
RAINFALL I~tTENSTTY - f111RATION TARLF (Til RE USEf1 w ITY SEWER nESTGN PROGRAM "4f1f\())
T T "'E 70'IF 1 7DNF ;> ZONE i 70NE 4 TN
MlNIITES 1n-vR 50-YR lr1-YR 'iO-YR 1n-vR 5n-yR !!1-VR 50-YR
14,() 4,54 6.13 3,8R "i' 1 0 3' 16 ll • 1 5 ),311 11 , 4 7
1 4 ' 1 4,5? 6. 11 J,Rt, 5,()8 3. 14 11 • 1 4 3.37 4,46 1 4. 2 4,51 1>,09 3,8'i '5,()7 3.13 It o\2 3,1A 4,44 1 4 • 3 4' 4 9 6,08 J,R4 "i,os 3' 11' II , 1 1 3,1b 4.42 1 4. 4 4,4FI i),Q() 3,8? <;,113 3' 11 /j' 09 3, :n 4' 4 1 liJ,'i 4,4A A,04 3 ' ill '5,01 3,09 /j '() 7 3,3? 4,40
1 II • 6 II, 115 1'.,0(' J,Rn 'i,OO 3.08 4,06 3 • :11 4,3A 1 4 '7 4,44 6,00 3,7A 4,08 3,07 1Je()4 3,3n 4.37 1 4 , R 4,4? 5,98 3,77 4,<J6 3.06 4.113 3,;><J /j ' 3 5 1 4. 9 4,41 5,96 3,7A 4,95 3,05 IJ,Il1 3. ;> 'l 4,34 1'i,O lj ' 3 q 5,9'5 3,75 4,Q3 3.04 4,0(1 3,;:>7 4,32
1 'i • l 4,3A 5.93 3,71 4,<12 3,02 1,<18 3,;><; 4' 3 1 1'i,;> 4. 37 5.91 3,7? {f. ~Q() 3,0! 'J,97 3,;:>4 4,29
1 "i ' ' 4,3') '5,89 3. 71 4,RA 3.00 'J,<l'i 3,21 4.28 1'io4 4. l4 'i,ll8 3' 7rl 4,R7 2,99 1!11Q4 3,2? 4,'?7 1 "i. 5 4' 3 3 'i,R6 3 .1\ R 4,R'i 2,98 1,92 3 ' ;> 1 lj' 2 5
1'i,6 4' 31 'S,I34 j,(,7' li, ~HI. 2.97 1,9! 3,;>1') 4,24 !'i' 7 4. 30 'J,A) 3,61'1 lj, R? 2,96 ~,A9 3,j9 lj ' 2 3 j'\,8 4,29 5,81 3,1\'; 4, R 1 2.95 'J,RA 3, 1 R 4.?1 1 5 '9 4.28 5,79 3 • 611 4,79 2,94 1,R7 3' 1 7 4.20 \1',,0 .4.26 5,78 3,6? 4. 7 7 2.93 'J,R"i 3' 11\ 4' 19
1"'. 1 4,2'5 5,76 3 • 6 1 4o76 2. 92 'loR4 3, I 5 4' 17 1"-·2 4,24 5,74 3. 61'1 4,75 2,91 ~.8? 3, ! 4 4' 1 6 1 1\ • 3 4. 2 3 5,73 3.5'1 4 ' 7' 3 2.90 ~, R I :l.t~ 4. 1 5 \1'>,4 4,21 5,71 3.5~ 4. 7 2 2,A9 1,RQ 3. 1, 4 ' 1 3 !Ao"i 4.20 5,70 3.57 4,70 2,81l 1,78 3 • 1 1 4' 1 2
)1\,6 4, I 9 5.68 ,,.,, 4,1'>9 2.87 <,77 3 ' 1 rJ 4 oil 1A,7 4, 1 B 5.66 3.55 4,1\7 2,Bfl <,71> J,oq 4. 1 0 )f>,/l 4. 1"' 5,65 3.5< 4.1'16 2,fl'i <,74 ),QR 4,0fl )1\,9 4. 15 5,63 3,5? 4,1\4 2o84 1.73 3,07 4,07 17,n 4' 14 5,62 3 • 5 1 lj ' "' 3 2,83 ~.7'? 3,07 4,06
1 7. 1 4. 1 3 5,60 3.50 4,1)2 2.82 1, 7 I 3,0, 4,05 j7,;> 4.12 5,59 3,4'l 4,1\0 2.81 1,1\9 3,/l'i 4,04 17.3 4. 11 5,'57 3,4R 4,59 2.80 ,,,fl 3,04 4,02 17,4 4,oq '3,56 3.47 4,'ifl 2.79 <.67 3.0< 4.01 17,5 4,(1fl 5,54 3,41\ 4,56 2.78 1,(,6 3,0? 4.00
1 7' 6 4.07 S,<;J 3,4'; 4,55 2,77 1,A4 3./lt 3,99 1 7' 7 4,!)11 '),51 3,44 4,"i4 2'1176 1,1'13 1.01'1 1,9R 1 7, A 4.Q5 o;,so 3.41 4,'i;? 2.75 ,,1);> ;:>,99 1,97 17,9 4,()4 '5,48 3,4? 4o'il 2.7'4 '. ">1 2.9~ 1,95
TP4E I"'TtRVAL llN THIS SHEFT " () ' 1 M l ~HITt 18
TABLE 3
I~!CI1lGAN OEPARTMENT OF STATE HIGHWAYS
RAINFALL !"!TENSITY ~ DURATION TARLF (TO BE USEI:l WITH SEWFR OESTGN PROGRAM 040A0)
TIME ZONE I. 7rJNE 2 ZONE ~ 70NE 4 !N
MINIITES tn~vR 5o~vR lO~YR so~vR !O~YR 5o~vR tO~VR so~vR
111,0 4.03 5.47 3. 41 4,50 2. 7 3 1,60 2,91'1 3,94
1 ll.l 4,0;:> 5.46 3,4(') 4.48 2.72 3,51l ;?,,91' 3.93 111.2 4,01 5,44 3. 3'1 4.47 2.7'2 1.57' 2,96 3,92 18' 3 4,00 5,43 3,311 4, II 6 2.71 1,56 ;:>,95 3,91 !Roll 3.99 5.41 3,37 4 ' /j 5 2.70 3,55 2,94 3' 90 18,'5 3,97 5,40 3 ' 31\ 4 '4 l 2,69 3,'54 2.93 3,89
111,6 3,96 5' 39 3,3'5 4,42 2.68 3' '53 2.9::1 3,88 11'1 ' 7 3,95 5,37 3 ' Jlj 4,41 2.67 l,'i! 2.92 3,87 !ll.ll 3,94 5,36 3,31 4,40 2,66 3,5(1 ;:>.91 1,85 !11,9 3,93 5,35 3' 3 ::> 4,38 2.66 '!,49 2,9(1 3,84 19,() 3,9;> '5,31 3' 11 4.37 2,65 ~.48 ;>,89 3 '8 3
19.1 3,91 5,32 3 ' 3 (1 4,36 2,64 "1,47 2' llA 3,82 19,2 3,90 5,3! 3.;>~ 4.35 2,63 1.46 ;>,811 3,81 )9,3 3,89 5.29 3,;>~ 4' '/j 2,62 3.45 ;>,81 3,fl0 )9,4 3,8R 5,28 3,211 4,32 2.61 3 , 4 II ;>,All 3,1'9 19,5 3,87 5,27 3,27 4' 31 2 ' (';.l ~.43 2.85 3,78
1<:1,6 3,86 5,25 3,;>6 4,30 2,60 3,42 ;>.85 3,77 19,7 3.85 5.24 J,?'i 4,;>9 2.59 1.4! 2.114 3,76 j9,B 3,84 5,23 3,24 4.28 2 '58 3,40 2.83 3,75 jQ,9 3,83 So22 3,23 4,;;7 2,57 3,39 2.112 1,74 20,(1 3,82 5,2() 3,2? 4.?6 2,57 1,~7 2,8? 3,73
21'1.1 3,81 5.t9 3' 2 !. 4,;::>4 2,56 "1.36 2.81 ~.72 20.2 3,80 5.!8 3.21 4.;>3 2.55 "1,35 2.80 3. 71 20,3 3,80 5' !7 3,20 4,;:>;> 2,54 ~ ,34 (',79 3,70 2f1,4 3,79 5d5 3.1<l 4,;>1 2.54 ~.33 2,79 3,69 20,5 3,78 5oi4 3, I A 4.20 2.53 ~.32 ;:>,711 3,61'1
2(1,6 3,77 5.13 3' 1 7 4' j 9 2.52 3.31 2,77 3,67 211,7 3,76 5.12 3.11\ 4.)8 2,51 "1,30 (',711 3,66 20,11 3,75 5' 11 3. 1"' 4.17 2.51 3.?9 2.76 3,65 20,9 3,74 5.09 3.1'5 4.16 2,50 "1,29 2 .. , 'I 3,64 21 '0 3,73 s,os 3.!4 4.!5 2,49 3.?8 2,74 3,1\4
21,! 3. 72 5,07 3oi3 4' 1 4 2,48 ~.27 2.74 3,63 21 '2 3,71 5,()6 3.12 4. 1 3 2.48 "1,?6 2,73 3,62 21 • 3 3,70 5,05 3.t2 4.11 2,47 3,;>5 2,7? 3,61 21. '4 3,70 5,04 3 .11. 4.10 2.46 ~.24 2' 71 ~.60
21 '5 3,69 5.o2 3' 10 4,09 2o46 ~. :n 2.1'1 3,59
21 '6 3,68 5,01 3,09 4,08 2,45 ~.;>;> 2•ro 3,58 21. '7 3.67 5,oo 3.08 4.07 2.44 ~.21 2.69 3,57 21 , a 3,611 4.99 3.011 4o06 2,43 3o?O 2,69 3,56 21 '9 3.65 4.98 3,07 4,05 2.43 3.19 2.68 3,55
TI '4E INTERVAL ON THIS SHEET " 0,1 MINUTE 19
TABLE 4
MICHIGAN rlEPARTMF.:NT OF 5TATE HIGHWAYS
RAINFALL I ~I TENSITY ~ DIIRATION TARLE <TO BE USED WTTH SEWER DESTGN PROGRAM rl4080)
TIME ZONE 1 ~ONt ? ZONE 1 70NE 4 IN
MTNUTES 1o~vR so~vR to~vR ';OmYR lOmyR 5f'1~yR jrleVR so~vR
2::>.0 3,64 4,97 3,(11', 4,04 2.42 '· 111 2.67 3,'05
22,1 3,64 4,96 3,0"\ 4 '113 2,41 1, I 7 2,67 ~.54
2?,2 3,63 4,95 3,04 4,0;> 2,41 1' 1. 6 2,6f> 3,53 22,3 3,62 4,93 3,()4 4,01 2,40 ~' 1"' 2.65 3,52 22,4 3,61 4,92 3,01 4,(1() 2' 39 '' 15
2,6'l 3,51 22,5 3,60 ,, '91 3,0:> 3,99 2,39 1' 14 2' 6il 3,50
2?,6 3,59 4,90 3,0::> 3,<l8 2.31'1 1' 13 2,1\1 3,49 2?,7 3,59 4,89 3. 01 3,9il 2.37
'· 1" 2.63 3,49
2?,8 3,58 4,88 3,011 3,G7 2' 37 3, I I 2·"'' 3' il8 2;>,9 3,57 4,87 2,9<) 3,96 2.36 ~' I 0 2.6? 3,47 2::1.0 .3,56 /j' 86 2,9<) 3,95 2.35 :l, 10 ?,1\1 3,46
2 ~.! 3,55 4,85 2,9A 3,94 2.35 1,()9 2,6(1 3,45 23,? 3,55 4,84 2,97 3,93 2,34 1,(')8 2 ,e;o 3,44 2 :l ,3 3,54 4,83 2,91\ 3.9? 2.34 ),()7 2,59 3,44 23.4 3,53 4,82 2,91) 3,9) 2.33 1,06 2,511 3,43 ;n,s 3,52 4,8) 2.9'l 3,90 2,3;> 3,()5 2.51l 3,4;?
23,6 3,5! I;, B 0 2. 9/j 3.89 2.32 1,()5 ;>,57' 3,41 23,7 3,51 4,79 2.94 3,88 2' 31 1,(14 2,57' 3,40 21,1\ 3,50 4,78 2,93 3,87 2.30 3.03 2,511 3,40 23,9 3,4<) 4,77 2.92 3,81) 2,30 1,();> ;>,5'5 3.39 211' 0 3,4A 4,76 2,9';> 1,116 2.29 ~.01 ;>,55 3,38
24.1 3,48 4,75 2,91 3.85 2.29 ~.oo 2,54 3,3 7 24.2 3,47 4,74 2,91') 3,84 2,28 3.00 2. 54 3,36 24,3 3,46 4' 73 2,90 3,83 2.27 ?,99 2,51 3.36 24,4 3,45 /j '7 2 2,89 3oA2 2.27 ?,98 2 '5? 3.35 24,5 3,45 4' 7 1 2.88 3,81 2.26 ,,97 ;:>,5:;> ~.34
24,6 3,44 4.70 2,81'1 3,110 2.26 :;>,97 ;>,51 3,33 24,7 3,43 4,69 2,87 3,79 2.25 ?,<)6 2. 5 j 1,33 24.~ 3.42 4,68 2.81\ 3,79 2o25 ;>,95 2,5() 3,32 24,9 3.42 4.67 2.81'1 3,1'8 2' 211 ?,94 2,5('1 3. 3 1 25.0 3.4\ 4,66 2,85 3,77 2.23 :;>,94 2,49 3,30
25 .t 3.40 4,65 2.84 3.76 2o23 ;>,93 2,4A 3,30 2">·2 3, 'I 0 4,64 2,84 3,75 2.22 ?,92 2.48 3,29 25.3 3' 3 9 II , 6 3 2.8~ 3,74 2·22 ;>,91 2.47' 1.28 25,4 3.38 4.62 2,8::> 3,74 2.21 ?.91 2,47 3,27 2'5,5 3,37 1! '61 2,8, 3,73 2.21 ?,90 2.41'1 3,27
25,6 3.37 4,60 2,81 3.72 2.20 '·1'19 2,4il 3,26 25.7 3,36 4,59 2oil0 3.71 2' 19 ;>,1\A ;>,45 3,25 25.11 3 .3'5 4,59 2' llO 3.70 2.19 ,,118 ;>,45 3.25 25,9 3.35 4,58 ;>,7Q 3.70 2.18 '.ll7 ;>,44 3,;>4
TI 'iE !NHRVAL ON THIS SHEET ., 0 ' I MINUTE
20
TABLE 5
MICHIGAN l'lEF'ARTMENT OF STATE HIGHWAYS
RATNF"All INTENSITY m DURATION TARLE no AE USE11 WITH SEWER OESTGN F'ROGRAM 04080)
TTME ZONE 1 ;>ONE 2 ZONE ~ 7DNE 4 TN
MINIITES to~vR 50mYR to~vR so~vR !OmyR 5(1myR to~vR 50•YR
21\,0 3,34 4,57 2.7<1 3.~9 2.18 ?,ll6 2,44 3,23
21\.1 3.33 4,56 2.711 3.68 2ol7 ?,115 2. 4 ~ 3.22 211.2 3,33 4,55 2.77 3,67 2d7 ::>,1\5 :;>,4::> 3o22 26.3 3 ,3?, 4,54 2.77 3.66 2.16 ::>.84 2.4? 3,21 2flo4 3.31 4,53 2o7f> 3,66 2d6 ?,113 ;:>.41 3o20 ;:>6,5 3.31 4.52 2o76 3.65 2d5 :>,A3 2o41 3o20
21'1,6 3,30 4.51 2.7"'> 3.64 2.15 :>,A;> 2,4(1 3.19 2(),7 3,29 4,51 2.74 3,63 2. !4 ?oil! 2,4(1 3.!8 21'1,8 3,29 4,5o 2.74 3.62 2<14 i'o81 2,3Q 3. 111 26,9 3,28 4,49 2.7~ 3,62 2.13 :>.110 2,3Q 3,)7 27.0 3,27 4,48 2.7~ 3,61, 2.!3 ?,7CJ 2.3~ 3.16
27 o1 3,27 4,47 2,7? 3,60 2.12 ;>,79 2,3A 3.16 ;>7,2 3,26 4,411 2.7'1 3,59 2.12 :>,7'8 2' 31' 3.15 27'.3 3.25 4,45 2.71 3.59 2.11 '?. 77 2' 37 3.14 27',4 3,25 4,45 2,7'0 3,58 2.11 ;>.77 2,3A 3.14 21',5 3,24 4,44 2.7'0 3,'57 2.10 ;>,711 2,36 3.! 3
27,6 3,23 I;, 4 3 2,6'l 3,'56 2.!0 ?,75 ;2,35 3.!2 ;>7,7 3,23 4,42 2,6<1 3,'i6 2,0<;1 ::>,75 2,35 3.t2 27,11 3,22 4,4! 2,611 3,55 2.09 ;>,74 2,34 3. 11 21',9 3,22 4,40 2,67 3,54 2.08 :>,73 2,34 3.10 211,() 3,21 4,40 2,67 3,54 2.08 ;>,73 ;:>, 33 3.10
28.1 3,20 4,39 2,61\ 3.'53 2.07 ?,72 ;>,33 3,09 211,2 3.20 4,38 2,611 3,52 2.07 ?,7! 2.3::> 3,08 211,3 3,19 II, 3 7 2,6'5 3,51 ;:>,01\ :>.71 2,3;> 3,08 211,4 3' 18 4,36 2.6'i 3,51 2.06 ?,70 2,31 3,07 211,'5 3,18 4,35 2.64 3,50 2o05 ;:>,69 2.31 3,06
28,1'1 3' 1 7 4,35 2,64 3,49 2.05 :>.69 2,30 3,06 28,7 3.t7 4,34 2,63 3,49 2.04 :>,611 2,30 3,05 21l,B 3.16 4,33 2.6~ 3,48 2.04 ;:>,(>8 2,30 3.05 21'1,9 3o15 4,32 2,6;> 3,47 2.03 :>,67 2,29 3,04 2<1,0 3.15 4,32 2' 6, 3,46 2.03 ;>,66 2,2<l 3,03
2<1.! 3.14 4,31 ?..61 3,46 2.02 ?,66 2,28 3,03 29,2 3,14 4,30 2,60 3,45 2o02 :>,65 2.2~ 3,02 2<;1,3 3' 13 4,29 2,6(1 3,44 2o01 ;:>,1)5 2.27 3,02 2'lo4 3,J2 4,28 z,s<~ 3.44 2·01 ;>,64 2o21' ::!,()1 29,5 3' 12 4,;:>8 2,5<1 3,43 2o00 ;> ,!'\ 3 2,2'> 3.00
2'l,6 3, 11 4,27 2,51'\ 3,42 2.00 ;>,63 2,21'. 3,00 2<1,1' 3.11 4,26 2,58 3,42 2o00 ::>.62 2.2'1 ;:>,99 29,8 3.10 4,25 2,57 3.41 lo99 ;>,62 2.2'5 ;:>,C/9 29,9 3.10 4,25 2,5'1' 3,40 lo99 ? ~d) 1 2,25 2,CJ8
TIME INTERVAL nN THIS SHEET " 0,1 MINUTE
21
TTME IN
MINUTES
30,6 30~1'1 31 • 0 31 '2 31 '4
31 '6 31 '8 32,0 3;>,2 32,4
32,6 3;>,8 33,1) 33,2 33,4
33,1\
33' ll 34.0 34.2 34.4
34,6 34,8 3'5.0 35,2 35,4
3'5,6 3'\,8 311;0 36.2 36,4
31'>,6 31'\,1\ 37.0 37 '2 37',4
ZONE
3,09 3,08 3,07
3,06 3.05 3,03 3,0? 3' (Ji
3,00 2,99 2.98 2,97 2,96
2,95 2' 91! 2,93 2,9;> 2,91
2,90 2,8'l 2,88 2,87 2.86
2o85 2,84 2,83 2.82 2,81
2.81 2.80 2,7() 2,78 2' 77
2,76 2,7'5 2.74 2' 73 2,73
2.72 2.71
MICHIGAN DEPARTMENT 0~ STATE HIGHWAYS
RA !NFALL !~!TENSITY ~ DIIRATION TARLF (TO BE USED WITH SEWER DESIGN PROGRAM 0408n)
1
I!, 2 4 4,22 4,21
4' 19 4' 1 8 4,16 4,15 lj d 4
4.12 4.11 4,09 4,08 4,07'
4,05 4,04 li '0 3 4,01 4,00
3,99 3,97' 3,96 3,95 3,93
3,92 3,91 3,90 3,88 3,87
3,86 3,85 3,84 3.82 3,81
3' 80 3,79 3,78 3,77 3,75
ZONE
2.53 2,5;> 2,5! 2,50 2,4'l
2.48 2,4A 2,47 2,4A 2oii'S
2' 411 2,43 2,4;> 2,4! 2,4(1
2,3<> 2,3Q 2.31'1 2,37' 2,3A
2d'5 2,34 2' 33 2.3~ 2,3;>
2' 3! 2,311 2.2'1 2.2'l 2.2!1
2.27' 2,2A 2·2"' 2,25 2,24
3' /j 0 3,38 3,37
3. 3 6 3,35 3' 33 3,32 3.31
3,30 3,?8 3.27 3,26 3,25
3.24 3.22 3,21 3,:>0 3' 1 9
3. 1 8 3' 1 7 3.!5 3.!4 3,13
3.!2 3.11 3.10 3,09 J,ns
3,07 3,06 3,05 3,04 3,03
3,02 3,01 3.00 2,90 2,'18
!.96 1.95 1,94 1,93 1 '9 2
1 '91 1 • 91 lo90 1o8'l 1,88
1 '8 7 1,87 1 '8 6 1 '8 5 1.84
1,84 1. 8 3 1.82 1.81 1 '8 1
1.60 1,79 1,7A 1.78 1 '77
1.76 1 '7 6 1.75 1.74 1.1'4
1 '7 3 1.1'2 1 '7 2 1 ' 'T 1 1,70
;>,57 ?,56 ;>,'55 ;>,54 ;>.52
?,51 ;>,'50 ;>,49 ;>,48 ;>,47
?,46 ::>.45 ::>,411 ?,43 2.42
? '/;1 ?,40 ;>,jQ
;>,38 ;>,37
;>' 36 ;>,.35 ?o34 ;>.33 ?,3::>
?.3::> ::>' 31 ::>.30 ?o29 ;>,;>8
?.27 ;>,;>6 ;>,;>5 ;>,::>4 ? , ;>II
TIME I~TERVAL llN THIS SHEET • 0,2 MINUTE 22
TABLE 6
ZONE
;:>,;:>4 2.23 2.2::>
2.21 2.21 (',('(1 2. 1 Q
(',!R
2' 17 2.16 2,11'> ?.1'5 2' 14
2.13 2.1? 2.12 2. 1 1 2.10
2,09 2,0Q 2,011 2. 01' 2.011
2,01\ 2,05 2 ,()4 2o03 2,03
2e0~
2.01 2.01 ;:>,oo !,9Q
1,91'\ 1 , 9 A !,97' 1,96 I ' 'l <'>
II
2.97 ::>,96 ;>,95
2,'l4 2,93 ;:>,92 ;>,91 ;>,89
2,88 2,87 2.116 ;:>,85 2,84
2,R3 ::>,82 2,51 ;>,80 2,7'J
;>,7'8 2,77 2,76 2.75 ;>.74
;>,73 2.72 ? '71 ;>,70 2,69
:;>,68 '2.67 2,66 ::>,65 2.64
2,63 ::>' 6 3 2·62 2.61 2,60
TABLE 7
M!CHl\,AN DEPARTMENT OF STATE HIGHWAYS
RAINFALL INTENSITY ~ OIIRATION TARLF" (TO BE USED WITH SEWER DESIGN PROGRAM 04080)
TIME ZONE 1 ZONE 2 ZONE ~ 70NE 4 YN
MINIITES to~vR so~vR to~vR so~vR to~vR 5'l*YR to~vR 50mYR
31'\,0 2.70 3,72 2.2? 2,'l5 !.68 2.?1 1 ''l4 ?.57 3A05 2,68 3,69 2,20 2,92 ),67 2.19 1 '92 ;>,55 39,0 2.66 3,67 2.11l 2,90 ),65 2' 1 7 1 • 91 2,53 39,5 2,64 3,64 2.!"' 2.88 ),64 ? '15 1,8Q 2o51 40,() 2.62 3.61 2' 1 'i 2aB6 1.62 , ' 1 3 1 , ll A 2.49 40,5 ;:>,60 3,59 2.13 2,113 1 '6 1 2' 11 1 , A"' ?.47 4 1 '0 2.58 3,56 2.11 :;>.8! ),59 2,09 ),85 2,45 4 I , 5 2.56 3,54 2.\fl 2,79 ),58 ;>,()8 1, A 3 2,43 42.0 2,54 3.51 2,0R ;>,77 1 '57 ;>,()6 1 '8? 2. 111 4?,5 ;>.53 3,49 2.07 2,75 1. 55 2,04 1 '8 () ;:>,39 43,0 2.51 3,46 2,05 2,71 1,54 ?,1)2 1 '7 9 2.38 43~5 2,49 :l,44 2.01 2' 7l 1 '53 ::>.01 \,?'A 2,36
411' 0 2,47 3,42 2,0? ;>,69 1 '51 1 • 9 <) 1.7~'> ;>,34 44,5 2,4n 3.39 2.01 ;>,fl7 1 'so I , 9 7 1 ' 7 'i ;>,)2 4'i,O 2.44 3,37 1 '9Q ;>,65 1,49 1 '96 1 '7 4 ;>,3! 45,5 2.42 3.35 1 , 9 R 2. '"' 1.48 1 ''14 1 '7' 2.29 41',,0 2.41 3,33 1,91'; 2.~1 1 • 4 6 1 '9 2 1 '71 2.27 I~ A, 5 2.39 3,31 1.9'5 2.!>0 1 • 4 5 1 ' <) 1 \,7fl 2,21) 47,0 2.37 3,;>8 1 • C) 3 ;>,58 1,44 \,A9 1 '6'1 ;>,24 47,5 2,36 3.26 ),9? ;>,'11\ 1 '4 3 1 , 8 A \,68 ;>,22 41l,o 2,34 3,;>4 1,91 2,'\4 1.42 1 ' 8 (\ \,fl6 2.21 48,5 2,33 3,22 ),8'1 2,52 1 '41 I , 1'15 ),6'i 2.19 49,0 2.31 3,20 ),811 :(,51 1.40 1 , B 4 1 • 6 4 2.18 4'1,5 2.30 3. 18 ),87 2.49 1,39 1 '8? I , 6 3 2' 16 sn.o 2.28 3.16 ),8,., 2,47 1 '3 8 1 , R 1 1 • 6 2 ?.15 50,5 2.27 3' 14 1,84 2.46 ),36 1.79 1. 61 2' 13 51 '0 2,25 3.12 ),83 ?,44 1.35 1 '7 8 1 , 6 n 2' 12 51 '5 2,24 3. 10 1,8? 2,43 1,34 1, 77 1 • 5 <l 2.10 52,0 2,23 3,09 1 ' Ill 2,41 1 '3 3 \,75 1 '57 2,09 52.5 2.21 3,07 ),8() 2.40 ),32 1 '7 4 1 '51'> ?,07 53,0 2,20 3,05 ),7fl 2,38 1. 31 1 , 7 3 1 '5 'i 2.06 53,5 2.19 3,03 1' 77 2,37 1 .31 1 ' 7 '2 1 '54 2.05 511. 0 2.!7 3,01 1,1'<'> ;>,35 ),30 1 '7 0 1 , 5' ;:>,03 5 /j. 5 2' 16 3,00 ),7'5 2.34 1 '2 9 1 '6 9 1 '5 ;> ?.02 5'1,0 2' 1 5 2,98 ),74 :;>. 32 ),28 1 ' 611 1 • 5! ?.01 5'1.5 2d3 2,96 1 '73 2' 31 l· 27 t '6 7 1.50 1,99 5A,(l 2.!2 2.94 1,72 ;>,;:>9 1.26 1 '66 1 '5 t) 1 • Q 8 51),5 2' 1l 2.93 1 '71 2,28 1.2'5 1 • 65 1 '4 9 1 , 9 r 57,0 2.10 2,91 1 ' 7 (1 2.27 1 '2 4 t.63 1 , 4 R 1 '96 57,5 2' Of\ 2,89 1,1'\9 :;>,25 1.23 1 , 62 1 ' 4 1' 1 '94
TIME I"lTERVAL f1N THIS SHEET " 0,5 MINUTE
23
TABLE 8
'llCHIGAN DEPARTMENT OF STAT!:: HIGHWAYS
RAINFALL INTENSITY ~ DURATION TA RLF: <TO BE USEO WITH SEWER DESIGN PROGRAM f140Afl)
TI 'IE ZONE 1 ZONE 2 ZONE ~ 70NE 4 IN
M!NtiTES tn~vR 5o~vR tn~vR so~vR !O~YR so~vR lO~YR so~vR
5A,O (!,07 ;:>,88 1. 6R ;:>,24 1. 2 3 1 '61 1 ' lj 6 1 '9 3 5<l,O 2,05 2,115 1,6A ?.?! 1.21 1 • 59 I , 4 4 t ' 9 1 60,0 2.03 2.82 1. 64 2' 1 9 1.19 j • o; 7 1,11? 1 , B 9
6 I , 0 2,00 2,79 1 , II? 2, I II 1.1 A 1 • '55 1 , II 1 1 , II 6 62,0 1 '9 8 2,76 1 '6fl 2' 1 4 1.16 1.'53 1 ' 3 () 1 '8 4 63,0 !. 96 ;;>,73 I , 5 fl 2.12 I.! 5 1 '51 1' 37 t. 82 64,0 1 '9 4 2,70 1 '5"' 2,09 1.13 1 '119 1.31i 1 '8 0 65,0 1 '9:? ?.,67 1.5'5 ;>,07 1.12 1 '4 7 1,34 t.78
66,0 1,90 2,64 1 '5, ;>,()5 1.! I j,46 1,31 !,76 67,0 1,8il 2,62 1 '51 ?,()3 1 '09 1 ' 114 1 '31 1,74 6/l,O 1 '8 6 2,59 1 '5 (') 2,00 1.08 1 '4 2 t.3n 1 '7 2 69,0 1. 84 2.56 l,llA 1 'q 8 1 '07 1 , Ill 1 , 2 A 1 '7 0 7f'l,O 1 • 82 2' 511 1.47 1 '9 6 1 '05 1.39 1 '2 7 1 '6 8
7 1 '0 1 '8 0 2,51 lo4'i 1 '9 4 1 '0 4 1 ' 3 7 1 '26 l '6 6 7;>,0 1 '7 9 2.49 1,44 1 'C) 2 ),03 1 '3 6 1.24 ),64 73,0 1.77 2,47 1,4? 1 '91 1.02 1 ' 3 4 1 '21 1.62 7 lj' 0 1.75 2,44 1 ' 4 1 1 'Fl9 1 '0 1 1 ' 3 3 1.22 1 '61 7'\,o 1,73 2.42 ),3'1 \,87 1, on 1 ' 3 t 1 , ;> n ),59
76,0 1 '7 ;:> 2,40 1,31'1 1.a<95 Q,98 1.,10 1 ' 1 9 I , 57 77,0 1,70 2,37 ),37 1 'fl3 0,97 j,;:>Q 1' 1 8 1.56 78,0 1,69 2,35 j,35 I , R 2 0,96 \ '27 1.! 7 ),54 7<1,0 1.67 2,33 1' 34 I , B 0 0,95 1o?6 1.16 1 '53 fll'l,O 1,6'5 :2,3! 1,3"! 1 '7 8 0,94 1.25 1,14 1 '51
81 '0 1 '6 4 ;>,;>9 1' 3 2 1 '7 7 0.93 1 ' ;:> 3 1' !3 1 '4 9 8;>,0 1 '6 ;> 2,27 1,30 1 '75 0.92 1 '22 1.1? 1 '4 8 83,0 1.61 2,25 1 '2<l 1 '7 3 0,91 1 '21 1 .11 1 '4 7 84,() 1 '6 0 2,23 1 '2 ('\ I , 7 2 Oo91 1 ' 2 () 1 ' 1 (1 1 '115 85,0 1 '58 2.21 1.27 I , 7 0 0.90 1.19 l,O<l 1 • 4 4
86,() 1.57 2' 1 9 1.2~ ),1\9 Q,ll9 1 ' 1 8 !,OR I , 4 2 87,0 1 '55 2,)7' 1 '2"i 1 ' 1\7 0.88 1 ' 16 ),()7 1 '4 1 81'\,0 1 '54 2.15 1 '24 1 '6 6 0.87 1 ' 1 5 1 '01'. 1 '4 0 89,() 1 '53 2.!3 1 '2 ~ 1 '65 0,86 I , 1 4 \,O'i 1' 38 9(),0 1 '51 2.12 1.22 1.63 0,85 1 ,)3 1 '04 1.37
91 '0 1 '50 2.!0 1 '21 ! '6 2 0,85 1.\2 1 '0 3 \,31'> 92.0 1,49 2,08 1, ::> n 1 '61 0,84 1.11 \,Of' 1.34 93,0 1,48 2,06 1 ' 1 0 !,59 Q,83 !dO 1, 0 I 1 ' 3 3 94,0 1,46 2,05 1 , Ill 1 • 58 0.82 1 ' (') Q 1. on 1,32 95,0 1 • 4 5 2,03 1 , I J' 1 • 51' 0,82 1 , OB 1 '0 (') 1 '31
96,0 1 '4 4 2,01 1,1(, 1 • 55 0,8! j ' 0 1' 0,99 1.30 97',0 1.43 2,00 1 ' 1 '5 1 '54 0.60 1 ' () 7 0,98 1 , 2 B
TIME INTERVAL nN THIS SHEET ~ 1.0 MINUTE 24
TABLE 9
MICHIGAN OEF'ARTMENT OF STATE HIGHWAYS
RAYNF"ALL ! ~!TENS! TY m DIIRATION TAtlLF (TO BE USED WITH SEWER DESIGN PROGRAM 04080)
TIME ZONE 1 70NE 2 ZONE 1 2'fJNE 4 IN
MINIITES lOmYR SOmYR !OmVR 50-YR 10-YR 50-VR !OmVR 50-YR
9/l,O 1,42 1,98 1 ,14 1 • 'i 3 0,79 1 • (){\ (),97 1 • 2 7 100,() 1,40 1,95 1 • 1 :> I ''\1 0,711 j,()4 0,95 I , 25 102.0 1 • 3 7 1 '9 2 1 • 1 (j 1 '4 8 0,77 1.02 0,94 1.23 104.0 1 .35 1,89 !,OQ 1 '4 6 0,76 1 ' () 1 0.9:? 1 ' 2 1
106.0 1,33 1,86 1,07 1 ' /j 4 0,74 11,99 0,91 t .19 1011,0 1 ' 3 1 1 , A 3 !.O"i 1 ' ,, 2 0.7'3 1'1,98 0,8'l 1.!7 110,0 1 '29 1 '81 1 '0 4 1 ' lj 0 0,72 (1,96 0,88 1 .15 11?.0 1,27 1 • 7 8 1.0::> 1.38 0,71 11,95 0,86 1.!3 1111,0 1 '25 1 • 75 1.01 1. '36 0,70 11,93 O,R"i 1 ' 1 1
111'1,0 1,24 1 '7 3 t.oo 1 '3 4 0,69 11,'12 (),114 1 • 09 11"1,0 1. 22 1,70 0,91'1 1 '32 0,68 (),91 O,ll3 1.07 120,0 1. 20 1,68 0,97 1 '3 0 0,67 n,<JO 0,81 1 '06 !22.0 1.19 1,66 0,91'> 1 ' :? 9 0,6(, 11 ' ill\ Q,IIO 1,04 124.0 1.17 1 '6 3 0.94 1 '? 7 (),65 n,R7 Q,1fl 1 '02
126,0 1.15 1 '61 0.9~ 1 '?5 0,64 (),81', 0,7R 1 '0 l !28,0 1 .14 1 '59 0.9::> 111 ?4 0,63 n,A5 0,71 0,99 !30,0 1.12 1 '57 0.91 1 • 22 0,62 n,A4 0,71'1 0,98 132,0 1 , I 1 1,55 0,911 1 • ? 1 0,62 n,ll3 o,7"i 0,96 !34,0 ),09 1 '53 (),80 1 .19 0,61 1'\,82 0,74 (),95
136' 0 1 • 0 ll 1 '"i 1 o.Bil 1 .,) 8 0.60 !l,R! o.7~ 0,94 138,0 1,07 1 '4 9 (),87 1 0 17 0,59 0,1'\0 0,7;> 0,92 14fl,O j,O':i 1,117 0,81'> 1 Q 1 5 0.59 O,lll) 0,7! (1,91 142.0 1 '0 4 1,45 Q,8"i 1 • 1 4 0,58 11,79 o,ro 0.90 !44,0 j,Q3 1 '4 3 0,84 1 .1 3 0,57 0,78 0,60 O,Bil
146.0 1,01 1 '41 0,81 1,) 1 0.57 (1,77 0,68 0,87 141'\,0 1 '00 1,39 0,8;> 1.10 0,51\ 11,7'6 0,1'17' 0,81\ 150,0 0,99 1,38 0,81 j,09 0.56 0.76 0,66 0,85 152.0 0,98 1,36 0,80 1 '() 8 0.55 (),75 0,1\5 0.83 154.0 0,96 1,34 0,79 1 • () 7 o,54 0,74 0.64 0.82
156.0 0,95 1. 33 0,711 1 '0 6 0.54 l'l,74 0,64 0.81 158,0 0,94 1 ' 31 0,71\ 1 '0 4 0' 53 11,73 0,63 0.80 !61'),0 0,93 I, 29 0.77 1 '0 3 0,53 0 .7'2 0.6? 0,79 16?,0 0,92 1 '2 8 o,7f, 1 • 0 2 0,52 n,72 0,6! 0.78 164,0 0.91 1 '26 0,7'5 1 '0 1 0.52 0,71 0,6! 0.77
166,0 0.90 I , 25 0,74 1 '0 0 0.51 11,70 Q,60 (),76 !6R,o 0,89 I , 2 3 Q,i'4 0,99 o.5t n,ro o,5Q [),75 170.0 0,88 1 '22 0' 73 0,98 0,50 n,6Q O,'iO 0,74 172.0 0,87 I , 20 0.72 0.97' Q,50 0,69 o,51l 0,73 1'1'4.0 0,86 1.19 0,7;> 0,97 0,50 0,1',8 0,57 o.r2
!76,0 0,135 1.18 0' 71 0,96 0.49 11,68 0,57 o. T1
TIME INTERVAL nN THYS SHEET " 2,0 MINUTES 25
TABLE 10
MICHIGAN DEPART~ENT OF STATE HIGHWAYS
RAYNFALL l~ITENS!TY ~ DURATION TARLF no 8E USEO 1• ITH SEWER OESTGN PROGRAM 04080)
TTME ZONE 1 70NE ;:> ZONE ~ ZONE 4 IN
M!NIITES to~vR so~vR lOmYR 50=YR \fJmVR 50myR lOmYR '50mYR
178,(1 0,84 ld6 o.ro Q,95 0,49 !1,67 o,sr, o,ro 180,0 0,83 1 .15 Q,J'() 0,94 0,48 n,67 o,5'i 0,69 182,0 0,82 1.14 0,69 (1,93 0,48 n,61\ 0,5'\ (),68 184,0 0,8\ 1 .12 0,69 Q,'l;:> 0.48 n,t'll\ 0 '511 O,t'lB
!81\,0 0.81 1 .11 0,611 0,91 0.47 1),66 0,53 0,67 1811,0 0.80 1 • 10 0,67 0,91 0,47 n,l'l5 0,53 0,66 190,0 0,79 1 '0 9 0,<'>7 O,<lO 0,47 n,65 0.52 (),65 192.0 0,78 1 '0 7 o,66 O,f\9 0. 116 11.64 0.5::> 0.64 194.0 o,77 1 • 06 (),61'. \l,ll8 0.46 n, "'11 0,51 0,64
196,0 0,76 1 '05 0,6'\ n ,IHl 0.46 (1,64 0,51 11,1>3 198,0 0,76 1 '0 4 0,6" 0.87 0.45 n,63 0,511 n,1>2 200.0 o,75 1.03 0' 611 (),1'\6 0.45 (),63 0,51'1 0.1'>1 202,0 0.74 1 '02 0,64 0,85 (),45 '1,63 0,4G 0,61 204,0 0,73 1 '00 0.6~ o,e5 0.45 f\,62 0,4<l 0,60
206,0 0,73 0,99 0,63 0,1'14 0,44 11,6:;> 0,4'1 0,59 ?.Oil,O 0,72 0,98 (),6, n,A4 0,44 n.62 O,IIA 0,58 210,0 0.71 0,97 0,65 0.113 0,44 n,61 0,4'1' 0,58 2\:',0 0' 71 0,96 0,61 0,82 0,44 (),61 0,41 0,57 214,0 0.70 0,95 0,61 o,R2 0,43 1'1,61 0,41'1 1),56
216,0 0,69 0,94 0 '61'1 O,P1 0,43 1'1,61 0,46 0,56 218,0 0,69 0,93 0,611 o.~o 0.43 1),60 0,4'\ 0,55 .220. 0 0,6A 0,92 0,60 o,Ro 0.43 0,60 0,45 0,55 222,0 0.67 0.91 0,5'1 0,79 0.42 (),6Q 0, II "i 0,54 2211,0 0,67 0,90 o,"i<l 0.79 0,42 n,6o 0.44 0,53
226,0 0,66 0,89 0,58 (1,78 0.42 ('),60 0,44 0,53 22A,O 0.65 0,88 o,5R o,7B Oo42 (),<;9 0,43 0,52 230,() 0,65 0,87 o,5fl o.rr 0.4;> 11,'i'l 0,43 ('),52 232,0 0,64 o,A7 0,51' 0' 77 Oo41 0.59 0,43 0,51 ;>34,0 0.64 0.86 o,57 o.r6 0.41 (),59 0.4::> 0,'51
236 '0 0.63 0,85 0,57' 0,76 0.41 !1,59 0,4;> 0,50 23A,O 0,62 0,84 Oo56 o.75 0,41 (1,58 0,41 0.49 240.0 0,62 0,83 o,51'l 0,75 0.41 o.5R 0,4! 0,49
TIME INTERVAL (IN THIS SHEET .. 2,0 MINUTES
26
.;
. ;· ....,;,_
t -j I
!
I ' .I !
l • ' ,.. . : ·' . i
.· ! . • '
.. "'"' I ' -.
1-.w .J .... ::::> 0
w. >( 0 ro <i .... z: 0 0.. w 1--0
~ ·w 0::
.... (/)
0
.. ~ ~ '"'=' -~
·o ....
·:r: (!)
w ::c
I ,1 •. ~ .. _..
500
400 ' EXAMPLE
t..:~: .. : : I , . Tc (MIN.)
200 300
200
150
50
40
30
20
10
5 4
.3
. . .· . ~. ,,. ·· ..... Height:: 100 Fl.
Longlh= 3,000 Fl. Time of concentrotion=I4Min:
' • : • • 0. :~ •
~: .... :•; q' ,' o I
; .... .
• -~ • __ .. ..;. • t
t . ~-. . f- 15; /)(\) . tL (FT.)
10,000
Nola:
. ···~=:-~~:.;.~. <. I "•• . .' :,._ .. • ,•
~· .. ~--.. :
-- .J -- w ..._>_
.q' .0:::
' . .... Use nomograph Tc for natural
basins with well defined channeLs,\::) for overland flow on bore :_ · :r: eorth,and for mowed gross road-:- .,_ side channels. : ;j:: ~
For overland flow, grossed sur~ · w . faces, multiply Tc by 2~ r. · ~- ... · .J
For overland flow, concreto or ; : .~ .. 5 asphalt surfaces, multiply Tc ·. ·:?! by0._4. ".~
For concrete channels, multiply . ~ · Tc by.o.2: .. ·::..:.:·-- ....... ; .. .-. ....... ~ .. ~r··;,; ~·
.· •')\.:· ......... ,_. :\.·-···;--·
L
5,000 z 0 -
1-<i
3000 o:::.-' . ....z: ----2 ooo · ...__w
t . "0
I "00 ·, ·---~Z >') . ·I 0 ' . .. (.)
~. · ... : 1,000 . ll.
200
150
100
. : 1' :~ .: •. :.~-· 0
. • .: .. ..·,I : .. · .. . -· ·:~ . .
------Sosed on sludy by P. Z. Kirpich, Civil Engineering, Voi.IO, No.6, June 1940, p. 362
.. •
..
150
100
80
60 50
40
20
15
10
6 5
4
3
2·
FIG. 5'--.,.TIME OF CONCENTRATION OF Sfv1ALL •.
• "1 • ...:.
.. ~.:·:. ·: ...... -· . . .... · ...
6-l'{ . : ... . ' ,. •. , ........ ·?· .. ;. ·: .
0- .'I
·'
I,
.
i
..
'·
I •
INFORMATIONAL MEHORANDUM
Subject: Drai.nage Desi.gn
II 93 - R 1/175 - B
February 26, 1973
The Water Resources Commission has jurisdiction over alterations of watercourses and floodplains in Hichigan in order to control construction which would create adverse backwater effects. They have prescribed the 100-year flood as the criteria by which the effect of backwater must be considered. /
/
Our past design criteria, originally advocated by Fill/A, was to design· for a 50-year flood. At a recent joint meeting of representatives of the Water Resources Commission, FHWA, and the Department, it was agreed in principle that on future drainage structures (bridges or culverts) the design would include consideration of the backwater effects of a 100-year storm.
A new design policy will be adopted when the details of implementing a 100-year flood design are developed. In the interim all bridges
·and culverts should be checked for headwater depths created by a 100-year flood, Preliminary rainfall intensity tables for a 100-year flood design are attached for Zones 1 and 2. (Zones referred to are
· shown on Figure 6, page llo, of the Design Division's manual, "Storm Sewer Design," dated December, 1967.) Complete tables for all zones will be distributed in the next few weeks.
Where there is considerable difference in construction cost in providing for the 100-year flood as opposed to the 50-year flood, the problem should be referred to Design Supervision.
r¢· tl ~ F. J. COOK
. Engineer - Design Section I
DD-JHW:mm
Att.
n:m;;::;:
1
•
·---- --~---·
100-Yt,l\1< RAI Nr'ALL '
fH1£' Z0NE I
I 5, 0 6.53 i6oO 6.36 17 .o 6o20 IR·O 6.05 19·0 5. 9 1 20·0 5. 77 21 • 0 5.65 22 ·0 5.53 23·0 5, Lt! 24o0 5.3') 25.0 58 ~~0 26.0 5. 1 0 27·0 5o00 28·0 4·91 29·0 4·82 30·0 4. 7 4 31 • 0 4o66 32·0 4o58 33·0 4·51 34·0 4o43 35.0 4o36 36·0 4·29 37 .o 4 ·2/3 3fJ.O 4ol6 39·0 4. 10 40·0 4·04 41 • 0 3·99 42·0 3·93 43•0 3. 87 411,0 3·82 45.o 3o77 46oO 3 o72 47·0 3. 67 48.0 3o62 49·0 3. 57 so.o 3; 53 51 • 0 3·49· 52.0 3 • 4Lt
-2-
INI't:i~SITIES
ZO:'W 2
5.'-!5 5.28 5. I?. 4o9R 4.8Lj 4o7l 4.59 4, Lio
4o37 4·27 4. I 8 4·09 4o00 3o92 3. 8/i 3.77 3o70 3.63 3" 57 3.51 3 .. L!5 3,39 3.33 3·2B 3o23 3.}8 3.]3 3o08 3·04 3o00 2o95 2.91 2. 87 2. 8/i 2·80 2. 7 6 2•73 2o69
I 00- n:Ai~ I~ A I ,'JVI\LL l<'JiT:\I:;r f li':S
I'I ME ZO,\IE I ZU.~!·: ~~
··------ ·'-··-53.0 3·110 2.66 5·4 .. o 3.36 2o63 ss.o 3.32 2o60 56.0 3o2fl 2o56 57 ·0 3o24 2·53 58o0 3·20 2~~51 59o0 3 ol7 2. /t8 6o.o 3 • I 3 2. /i5
61 • 0 3. 10 2 o LJ2 62.0 3·06 2·39 63.0 3o03 2.37 64.0 2·99 2. 3/i . 65·0 2.96 2·32 66.0 2 •. 93 2o29 67 .o 2·90 2 ·27 68o0 2. 37 2o25 69o0 2. 811 2o23 70o0 2. 81 2·20 7 1 • 0 2.7 8 2. 1 8 72·0 2. 7 5 2.]6 7 3 .o 2. 7 3 2 .. 14 7'1·0 2. 70 2.}2 7 5 .o 2. 67 2o!O 7 6 ·0 2. 65' 2·08 11·0 2o62 2·06 18·0 2.60 2·04 19 ·0 2. 57 2o02' 80·0 2.55 2 •. oo 81 .o 2.52 I • 9 9 82 ·0 2. 50 I • 97 83·0 2·48 I • 95 84·0 2.45 I • 93 85o0 2 • Lt3 1 • 92 86oO 2·41 1 • 90 87 ·0 2·39 1 • 139 88·0 2. 37 1 • 87 89·0 2·35 1 • 85
. 90 .o 2o33 I • 134
(
-3-
··-· ---· ·--
1 oo-n:A1~ RAPFI\LL I NTf.N.'> IT I E:S I 00-Y[I\1~ HI\J. NI''AI.L IN 1'1-:N:.; IT II::·;
TII'1E ZONE I Z0NE 2 TIME ZONE I Z0NF. 2
91 • 0 2·31 I • 82 12t:.o I • 7 4 t , LJO
92 .o 2·29 1 • 81 129·0 I • 7 3 1 • 40
93 .o 2.27 I • 7 9 130·0 I , 7 2 I • 39 9LJ, 0 2 ·25 I , 7 g I 3 I • 0 I , 7 0 I . 3 c;
, ..
'95 .o 2·23 1 .n 132 •. o I • 6 9 1 • 37 96.0 2·21 1 <l 7 5 133.0 l • 6 8 I • 3 6
I 134·0 i .35 19'1·0 2ol9 I , 7 4 I • 67
1 9D .. o 2. 17 l • 7 3 135.0 I • 6 6 I , 3 5
99·0 2.\6 I , 7 I 136·0 I. 65 I • 3 4 100·0 2 ,j IJ l • 7 0 137·0 I , 64 I • 33 I 0 I , 0 2ol2 1 • 6 9 138.0 1 • 63 1 0 32 102.0 2.\0 1 • 67 139.0 I • 62 I • 3 I 103.0 2·09 I , 66 HO.Q I • 6 I 1 • 3 I 101/oO 2. 07 ] e 65 I 4 1 • 0 I • 60 i . 30 105·0 2·06 I , 64 l/~~~.o · I • 59 l • 29 106.0 2. OIJ I , 63 143;0 1 "53 I • 2 fl 1 07.0 2o02 I • 6 I I LJ4 .o 1 • 57 I • 2 f3
108·0 2-• 0 I I • 60 145.0 I , 56 I • 27 109·0 I • 99 I • 59 J/i6oO I , 55 I • 26 110·0 1 • 9 8 1 $58 I /i7 • 0 I , 5LJ l .26 I 1 1 • 0 1. 96 I • 57 1118•0 1 0 53 ·t .. 25
112·0 1 .. 9 5 1, 56 1''19·0 1 0 52 1 "2/J 113·0. 1 • 93 1 • 55 150.0 I ·51 .l 0 :~ /j
114·0 1 $ 92 1·54 I 51 • 0 I • 50 1 • 2<1
I 1 5 • 0 I , 9 I 1 .. 53 152.0 I • 50 I • 22 I 1 6. 0 I • B 9 1. 52 153.0 j • IJ9 i. 22 1 I 7 • 0 I • 88 1 • 5 I I 5LJ. 0 1 • 48 l • 21' 118·0 1 "g6 1 • 50 155.() I • 47 1. 20; 1 I 9 • 0 I dl5 I • 49 156.0 I • 46 . 1 • 20 120'·0 I • 8L1 I • :ll 8 157.1) I • 4 5 I • 1 9
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