1997-5317 G
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Name
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Serial #
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K&S ENGINEERING
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HYDROLOGICAL
(lliŒ û2 ~ n 117 r~IH'
NOV 12 1997 j
ENGINEERING SERVICES
CITY OF ENCINITAS
ANALYSIS
FOR
WILDFLOWER ESTATES LOT 15
IN
CITY OF ENCINITAS
..
IN 9749
November 6, 1997
III
II /;0/17
DA'PE '
780 Mi sion Center Co 11, Suite 200.San Diego, California 92108. (619)296-5565 . Fax (619)296-5564
..
TABLE OF CONTENTS
I.HYDROLOGY DESIGN MODELS
2.HYDROLOGIC CALCULATIONS .......................... APPENDIX A
3.TABLES AND CHARTS ..........,..................... APPENDIX B
4.HYDROLOGY MAPS ................................... APPENDIX C
"
1.
HYDROLOGY DESIGN MODELS
A.
DESIGN METHODS
THE RATIONAL METHOD IS USED IN THIS HYDROLOGY STUDY; THE RATIONAL
FORMULA IS AS FOLLOWS:
Q = CIA, WHERE: Q= PEAK DISCHARGE IN CUBIC FEET/SECOND *
C = RUNOFF COEFFICIENT (DIMENSIONLESS)
I = RAINFALL INTENSITY IN INCHES/HOUR
A = TRIBUTARY DRAINAGE AREA IN ACRES
*1 ACRE INCHES/HOUR = 1.008 CUBIC FEET/SEC
THE OVERLAND FLOW METHOD IS ALSO USED IN THIS HYDROLOGY STUDY; THE
OVERLAND FLOW FORMULA IS AS FOLLOWS:
To=[1.8(1.1-C) (L),5]/(S%)1/3
C = RUNOFF COEFFICIENT
L = OVERLAND TRAVEL DISTANCE IN FEET
S = SLOPE IN PERCENT
To= TIME IN MINUTES
B.
DESIGN CRITERIA
- FREQUENCY, 100 YEAR STORM.
- LAND USE PER SPECIFIC PLAN AND TENTATIVE MAP.
- RAIN FALL INTENSITY PER COUNTY OF SAN DIEGO 1993 HYDROLOGY
DESIGN MANUAL.
C.
REFERENCES
- COUNTY OF SAN DIEGO 1993, HYDROLOGY MANUAL.
- COUNTY OF SAN DIEGO 1992 REGIONAL STANDARD DRAWING.
- HAND BOOK OF HYDRAULICS BY BRATER & KING, SIXTH EDITION.
)
APPENDIX A
(2. HYDROLOGIC CALCULATIONS)
..
SAN DIEGO COUNTY
RATIONAL-HYDROLOGY
PROGRAM PACKAGE
Rational Hydrology Study
Date: 11-11-1997
_u_----------------------------------------------------------___n_--__n_-
*USER SPECIFIED HYDROLOGY INFORMATION*
--------------_u_u_----------------------u_------------------------------
Rational method hydrology program based on
San Diego County Flood Control Division
1985 Hydrology Manual
Storm Event(Year) = 100.00
Map data precipitation entered:
6 HOUR, Precipitation(Inches) = 2.700
24 Hour Precipitation(Inches) = 4.500
Adjusted 6 Hour Precipitation (Inches) = 2.700
P6/P24 = 60.0 %
San Diego Hydrology Manual "C" Values Used
Runoff Coefficients by RATIONAL METHOD
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 1.000 to Point/Station 5.000
*** INITIAL AREA EVALUATION ***
Decimal Fraction Soil Group A = .000
Decimal Fraction Soil Group B = .000
Decimal Fraction Soil Group C = .000
Decimal Fraction Soil Group D = 1.000
RURAL (lots> 1/2 acre) runoff coefficient = .4500
Area Type is: RURAL (Greater than 1/2 Acre)
Time of concentration computed by the Natural
Watersheds nomograph, (App. X-A)
TC = (11.9*Length(Mi)^3)/(Elevation Change))^.385*60(MIN/HR)
+ 10 min.
Initial Subarea Flow Dist. = 100.00
Highest Elevation = 359.00
Lowest Elevation = 356.50
Elevation Difference = 2.50
TC = [(11.9* .0189**3)/( 2.50))**..385 = 1.120
+ 10 Min. = 11.120 Min.
100.00 Year Rainfall Intensity(In./Hr.) = 4.248
Subarea(Acres) = .12 Subarea Runoff(CFS) =
Total Area(Acres) = .12 Total Runoff(CFS) =
TClMIN) = 11.l2
.23
.23
++++++++++++++++++++++++++++++++++++++++11111111111+++1111111++++++++++++++
Process from Point/Station 5.000 to Point/Station 2.000
... PIPEFLOW TIME (USER SPECIFIED SIZE) ...
Upstream point elevation = 356.50
Downstream point elevation = 355.00
Flow length(Ft.) = 75.00 Mannings N = .013
No. of pipes = I Required pipe flow (CFS) =
Given pipe size (In.) = 24.00
Calculated Individual Pipe flow (CFS) =
Nonnal flow depth in pipe = 1.45 (In.)
Flow top width inside pipe = 11.43 (In.)
Velocity = 2.956 (Ft/S)
Travel time (Min.) = .42 TC(min.) = 11.54
.23
.23
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++111111111++++++++
Process from Point/Station 2.000 to Point/Station 3.000
**. PIPEFLOW TIME (USER SPECIFIED SIZE) ...
Upstream point elevation = 355.00
Downstream point elevation = 314.00
Flow length(Ft.) = 288.00 Mannings N = .013
No. of pipes = 1 Required pipe flow (CFS) =
Given pipe size (In.) = 24.00
Calculated Individual Pipe flow (CFS) =
Normal flow depth in pipe = .92 (In.)
Flow top width inside pipe = 9.19 (In.)
Velocity = 5.848 (Ft/S)
Travel time (Min.) = .82 TC(min.) = 12.36
.23
.23
+++++++++++++++++++++++++++++++++++++++111111111+++++++++++++++++++++++++++
Process from Point/Station 2.000 to Point/Station 3.000
*** SUBAREA FLOW ADDITION ",*
100.00 Year Rainfall Intensity(In./Hr.) = 3.967
Decimal Fraction Soil Group A = .000
Decimal Fraction Soil Group B = .000
Decimal Fraction Soil Group C = .000
Decimal Fraction Soil Group D = 1.000
RURAL (lots> 1/2 acre) runoff coefficient = .4500
Subarea(Acres) = .40 Subarea Runoff(CFS) =
Total Area(Acres) = .52 Total Runoff(CFS) =
TC(MIN) = 12.36
.71
.94
+++++++++++++++++++++++++++++++++++111111111111111111111++++++111111111111+
Process from Point/Station 2.000 to Point/Station 3.000
*** CONFLUENCE OF MINOR STREAMS ...
----_u------------------------_uuu--_u_--_u---------------------------
100.00 Year Rainfall Intensity(In./Hr.) = 3.967
ALONG THE MAIN STREAM NUMBER: 1
The flow values used for the stream: 1 are:
Time of concentration(min.) = 12.36
Rainfall intensity (in./hrl) = 3.97
Total flow area (Acres) = .52
Total runoff (CFS) at confluence point =
.94
++++++++++++++++++++111111++++++++++++++++++++++111111+++++++++++++++++++++
Process from Point/Station 4.000 to Point/Station 7.000
*** INITIAL AREA EVALUATION ***
Decimal Fraction Soil Group A = .000
Decimal Fraction Soil Group B = .000
Decimal Fraction Soil Group C = .000
Decimal Fraction Soil Group D = 1.000
RURAL (lots> 1/2 acre) runoff coefficient = .4500
Area Type is: RURAL (Greater than 1/2 Acre)
Time of concentration computed by the Natural
Watersheds nomograph, (App. X-A)
TC = [11.9*Length(Mi)^3)/(Elevation Change)]^.385*60(MIN/HR)
+ 10 min.
Initial Subarea Flow Dist. = 200.00
Highest Elevation = 358.50
Lowest Elevation = 346.00
Elevation Difference = 12.50
TC = [(11.9* .0379**3)/( 12.50)]"..385 = 1.343
+ 10 Min. = 11.343 Min.
100.00 Year Rainfall Intensity(ln./Hr.) = 4.194
Subarea(Acres) = .34 Subarea Runoff(CFS) =
Total Area(Acres) = .34 Total Runoff(CFS) =
TC(MIN) = 11.34
.64
.64
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 7.000 to Point/Station 6.000
*.. PIPEFLOW TIME (USER SPECIFIED SIZE) *..
Upstream point elevation = 346.00
Downstream point elevation = 344.00
Flow length(Ft.) = 95.00 Mannings N = .013
No. of pipes = 1 Required pipe flow (CFS) =
Given pipe size (In.) = 24.00
Calculated Individual Pipe flow (CFS) =
Normal flow depth in pipe = 2.33 (In.)
Flow top width inside pipe = 14.20 (In.)
Velocity = 4.110 (Ft/S)
Travel time (Min.) = .39 TC(min.) = 11.73
.64
.64
+111111111111111111111111111111111111111111111111111111111 11111 11111 III II!!
Process from Point/Station 6.000 to Point/Station 8.000
.u PIPEFLOW TIME (USER SPECIFIED SIZE) u.
Upstream point elevation = 337.00
Downstream point elevation = 326.95
Flow length(pt.) = 42.58 Mannings N = .013
No. of pipes = 1 Required pipe flow (CFS) =
Given pipe size (In.) = 6.00
Calculated Individual Pipe flow (CFS) =
Normal flow depth in pipe = 1.98 (In.)
Flow top width inside pipe = 5.64 (In.)
Velocity = 11.348 (pt/S)
Travel time (Min.) = .06 TC(min.) = ] 1.79
.64
.64
++11111111+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 8.000 to Point/Station 9.000
u. PIPEFLOW TIME (USER SPECIFIED SIZE) .u
Upstream point elevation = 326.95
Downstream point elevation = 325.02
Flow length(pt.) = 192.22 Mannings N = .013
No. of pipes = 1 Required pipe flow (CFS) =
Given pipe size (In.) = 8.00
Calculated Individual Pipe flow (CFS) =
Normal flow depth in pipe = 4.14 (In.)
Flow top width inside pipe = 7.99 (In.)
Velocity = 3.520 (pt/S)
Travel time (Min.) = .91 TC(min.) = 12.70
.64
.64
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++1111111++++
Process from Point/Station 8.000 to Point/Station 9.000
u. SUBAREA FLOW ADDITION u.
100.00 Year Rainfall Intensity(In./Hr.) = 3.899
Decimal Fraction Soil Group A = .000
Decimal Fraction Soil Group B = .000
Decimal Fraction Soil Group C = .000
Decimal Fraction Soil Group D = 1.000
RURAL (lots> 1/2 acre) runoff coefficient = .4500
Subarea(Acres) = .57 Subarea Runoff(CFS) =
Total Area(Acres) = .91 Total Runoff(CFS) =
TC(MIN) = 12.70
1.00
1.64
++1111111111111111++++++++++++++++++++11111111++++1111111++++++1111111+++++
Process from Point/Station 9.000 to Point/Station 3.000
u. PIPEFLOW TIME (USER SPECIFIED SIZE) . u
Upstream point elevation = 325.02
Downstream point elevation = 314.00
Flow length(Ft.) = 43.17 Mannings N = .013
No. of pipes = 1 Required pipe flow (CFS) =
Given pipe size (In.) = 10.00
Calculated Individual Pipe flow (CFS) =
Nonnal flow depth in pipe = 2.60 (In.)
Flow top width inside pipe = 8.78 (In.)
Velocity = 14.553 (Ft/S)
Travel time (Min.) = .05 TC(min.) = 12.75
1.64
1.64
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 9.000 to Point/Station 3.000
*** CONFLUENCE OF MINOR STREAMS ***
*** Compute Various Confluenced Flow Values ***
--------------------------------------------------------------------n------
100.00 Year Rainfall Intensity(In./Hr.) = 3.889
ALONG THE MAIN STREAM NUMBER: 1
The flow values used for the stream: 2 are:
Time of concentration(min.) = 12.75
Rainfall intensity (in./hrl) = 3.89
Total flow area (Acres) = .91
Total runoff (CFS) at confluence point =
1.64
Confluence infonnation:
Stream runoff Time Intensity
Number (CFS) (min.) (inch/hour)
------------------------------------------------------------n--------------
1 .94
2 1.64
QSMX( 1) =
+ 1.000* 1.000*
+ 1.000. .970.
2.536
QSMX(2) =
+ .980.1.000.
+ 1.000.1.000.
2.567
12.36
12.75
3.967
3.889
.9)
1.6)
.9)
1.6)
Rainfall intensity and time of concentration
used for 2 streams.
Individual stream flow values are:
.94 1.64
Possible confluenced flow values are:
2.54 2.57
Individual Stream Area values are:
.52 .91
L_.____---.--..------..--.-..----- "'.00
Computed confluence estimates are:
Runoff(CFS) = 2.57 Time(min.) = 12.750
Total main stream study area (Acres) = 1.43
++1111111111111111111111111111+11111111111111111111+1111111+++++11111111111
Process from Point/Station 10.000 to Point/Station 7.000
..* INITIAL AREA EVALUATION *..
Decimal Fraction Soil Group A = .000
Decimal Fraction Soil Group B = .000
Decimal Fraction Soil Group C = .000
Decimal Fraction Soil Group D = 1.000
RURAL (lots> 1/2 acre) runoff coefficient = .4500
Area Type is: RURAL (Greater than 1/2 Acre)
Time of concentration computed by the Natural
Watersheds nomograph, (App. X-A)
TC = [11.9*Length(Mi)^3)/(Elevation Change)]^.385*60(MIN/HR)
+ 10 min.
Initial Subarea Flow Dist. = 136.00
Highest Elevation = 356.50
Lowest Elevation = 346.00
Elevation Difference = 10.50
TC = [(11.9* .0258**3)/( 10.50)]**..385 =
+ 10 Min. = 10.920 Min.
100.00 Year Rainfall Intensity(In./Hr.) = 4.298
Subarea(Acres) = .29 Subarea Runoff(CFS) =
Total Area(Acres) = .29 Total Runoff(CFS) =
TC(MIN) = 10.92
.920
.56
.56
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 7.000 to Point/Station 11.000
*.. PIPEFLOW TIME (USER SPECIFIED SIZE) ***
Upstream point elevation = 346.00
Downstream point elevation = 342.00
Flow length(Ft.) = 157.00 Mannings N = .013
No. of pipes = 1 Required pipe flow (CFS) =
Given pipe size (In.) = 24.00
Calculated Individual Pipe flow (CFS) =
Normal flow depth in pipe = 2.08 (In.)
Flow top width inside pipe = 13.52 (In.)
Velocity = 4.216 (Ft/S)
Travel time (Min.) = .62 TC(min.) = 11.54
.56
.56
1 I I I 1 1 I I 1 1 + + 1 I 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 +++++ ++++ I 1 1 1 1 1 1 1 1 I I I 1 1 1 I 1 1 1 1 I I I I 1 1 + +++ + +++ +
Process from Point/Station 11.000 to Point/Station 12.000
*.. PIPEFLOW TIME (USER SPECIFIED SIZE) *..
Upstrcam point elevation = 342.00
Downstream point elevation = 309.50
Flow length(Ft.) = 187.00 Mannings N = .013
No. of pipes = I Required pipe flow (CFS) =
Given pipe size (In.) = 24.00
Calculated Individual Pipe flow (CFS) =
Nonnal flow depth in pipe = 1.33 (In.)
Flow top width inside pipe = 10.97 (In.)
Velocity = 8.229 (Ft/S)
Travel time (Min.) = .38 TC(min.) = 11.92
.56
.56
+++11111111111++++++++++++++++++++++++++++++++++1111111111+++++++++++++++++
Process from Point/Station 11.000 to Point/Station 12.000
*** SUBAREA FLOW ADDITION ***
100.00 Year Rainfall Intensity(In./Hr.) = 4.062
Decimal Fraction Soil Group A = .000
Decimal Fraction Soil Group B = .000
Decimal Fraction Soil Group C = .000
Decimal Fraction Soil Group D = 1.000
RURAL (lots> 1/2 acre) runoff coefficient = .4500
Subarea(Acres) = .08 Subarea Runoff(CFS) =
Total Area(Acres) = .37 Total Runoff(CFS) =
TCCMIN) = 11.92
.15
.71
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 11.000 to Point/Station 12.000
*** CONFLUENCE OF MINOR STREAMS ***
-----------------------------------------------------------------------_n_-
100.00 Year Rainfall Intensity(In./Hr.) = 4.062
ALONG THE MAIN STREAM NUMBER: 1
The flow values used for the stream: 1 are:
Time of concentration(min.) = 11.92
Rainfall intensity (in./hrl) = 4.06
Total flow area (Acres) = .37
Total runoff (CFS) at confluence point =
.71
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 7.000 to Point/Station 13.000
*** INITIAL AREA EVALUATION ***
Decimal Fraction Soil Group A = .000
Decimal Fraction Soil Group B = .000
Decimal Fraction Soil Group C = .000
Decimal Fraction Soil Group D = 1.000
.":"-:-~'~""",~"",,,,-.:",",",-'n~"_',_,-,'-'-'-" .
RURAL (lots> 1/2 acre) runoff coefficient = .4500
Area Type is: RURAL(Greater than 1/2 Acre)
Time of concentration computed by the Natural
Watersheds nomograph, (App. X-A)
TC = (l1.9*Length(Mi)^3)/(Elevation Change)]^.385*60(MIN/HR)
+ 10 min.
Initial Subarea Flow Dist. = 29.00
Highest Elevation = 346.00
Lowest Elevation = 333.00
Elevation Difference = 13.00
TC = [(11.9* .0055**3)/( 13.00)]**..385 =
+ 10 Min. = 10.142 Min.
100.00 Year Rainfall Intensity(In./Hr.) = 4.508
Subarea(Acres) = .08 Subarea Runoff(CFS) =
Total Area(Acres) = .08 Total Runoff(CFS) =
TC(MIN) = 10.14
.142
.16
.16
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 13.000 to Point/Station 14.000
*** TRAPEZOIDAL/RECT. CHANNEL TRAVEL TIME ***
Upstream point elevation = 333.00
Downstream point elevation = 330.95
Channel length thru subarea(F eel) = 187.00
Channel base(Feet) = .00
Slope or "Z" of left channel bank = 2.000
Slope or "Z" of right channel bank = 50.000
Mannings "N" = .013 Maximum depth of channel (Ft.) = 2.00
Flow(Q) thru subarea(CFS) = .16
Upstream point elevation = 333.00
Downstream point elevation = 330.95
Flow length(Ft.) = 187.00
Travel time (Min.) = 2.44 TC(min.) = 12.59
Depth of flow = .07 (Ft.)
Average Velocity = 1.28 (Ft./Sec.)
Channel flow top width = 3.64 (Ft.)
111111+++++1111111111111+++++++++++++++++1111111+++++++++++++++++++++++++++
Process from Point/Station 13.000 to Point/Station 14.000
* * * SUBAREA FLOW ADDITION * * *
100.00 Year Rainfall Intensity(In./Hr.) = 3.922
Decimal Fraction Soil Group A = .000
Decimal Fraction Soil Group B = .000
Decimal Fraction Soil Group C = .000
Decimal Fraction Soil Group D = 1.000
RURAL (lots> 1/2 acre) runoff coefficient = .4500
Subarea(Acres) = .34 Subarea Runoff(CFS) =
Total Area(Acres) = .42 Total Runoff(CFS) =
TC(MIN) = 12.59
.60
.76
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 14.000 to Point/Station 15.000
u. PIPEFLOW TIME (USER SPECIFIED SIZE) u.
Upstream point elevation = 326.95
Downstream point elevation = 321.95
Flow length(Ft.) = 23.96 Mannings N = .013
No. of pipes = 1 Required pipe flow (CFS) =
Given pipe size (In.) = 6.00
Calculated Individual Pipe flow (CFS) =
Normal flow depth in pipe = 2.24 (In.)
Flow top width inside pipe = 5.81 (In.)
Velocity = 11.385 (Ft/S)
Travel time (Min.) = .04 TC(min.) = 12.62
.76
.76
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 14.000 to Point/Station 15.000
... SUBAREA FLOW ADDITION ...
100.00 Year Rainfall Intensity(In./Hr.) = 3.915
Decimal Fraction Soil Group A = .000
Decimal Fraction Soil Group B = .000
Decimal Fraction Soil Group C = .000
Decimal Fraction Soil Group D = 1.000
RURAL (Jots> 1/2 acre) runoff coefficient = .4500
Subarea(Acres) = .05 Subarea Runoff(CFS) =
Total Area(Acres) = .47 Total Runoff(CFS) =
TC(MIN) = 12.62
.09
.85
11111111111++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 15.000 to Point/Station 16.000
u. PIPEFLOW TIME (USER SPECIFIED SIZE) u.
Upstream point elevation = 321.95
Downstream point elevation = 321.36
Flow length(Ft.) = 59.50 Mannings N = .013
No. of pipes = 1 Required pipe flow (CFS) =
Given pipe size (In.) = 8.00
Calculated Individual Pipe flow (CFS) =
Normal flow depth in pipe = 4.96 (In.)
Flow top width inside pipe = 7.76 (In.)
Velocity = 3.737 (Ft/S)
Travel time (Min.) = .27 TC(min.) = 12.89
.85
.85
++++++++++++++111111+++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 15.000 to Point/Station 16.000
... SUBAREA FLOW ADDITION ...
.~-".-' "~""~"-".'."~.~"""
\./;
100.00 Year Rainfall Intensity(In./Hr.) = 3.863
Decimal Fraction Soil Group A = .000
Decimal Fraction Soil Group B = .000
Decimal Fraction Soil Group C = .000
Decimal Fraction Soil Group D = 1.000 ,
RURAL (lots> 1/2 acre) runoff coefficient = .4500
Subarea(Acres) = .06 Subarea Runoff(CFS) =
Total Area(Acres) = .53' Total Runoff(CFS) =
TC(MlN) = 12.89
.10
.95
+++++++++++++++++11111111111111111111+111111111111111111+++++++++++++++++++
Process from Point/Station 16.000 to Point/Station 12.000
.** PIPEFLOW TIME(USER SPECIFIED SIZE) .**
Upstream point elevation = 321.36
Downstream point elevation = 309.50
Flow length(Ft.) = 44.48 Mannings N = .013
No., of pipes = 1 Required pipe flow (CFS) =
Given pipe size (In.) = 8.00
Calculated Individual Pipe flow (CFS) =
Normal flow depth in pipe = 2.12 (In,)
Flow top width inside pipe = 7.06 (In.)
Velocity = 12.932 (Ft/S)
Travel time (Min.) = .06 TC(min.) = 12.94
.95
.95
+++++++++++1111111111+++++1111111++++++++++++111111111+++++++++++++++++++++
Process from Point/Station 16.000 to Point/Station 12.000
**. CONFLUENCE OF MINOR STREAMS .**
----------------------------------------------------------------------------
100.00 Year Rainfall Intensity(In./Hr.) = 3.852
ALONG THE MAIN STREAM NUMBER: 1
The flow values used for the stream: 2 are:
Time of concentration(rnin.) = 12.94
Rainfall intensity (in./hrl) = 3.85
Total flow area (Acres) = .53
Total runoff (CFS) at confluence point =
.95
, " ',' ,
+++++++++++++++++IIIIIIIIIIIIIII"IIIÎlllllllllllllllllllllIIIIIIIII1I1IIIIII
, , ' , "'
Process from Point/Station 17.000'to Point/StatiôIÌ, 18.000
**. INITIAL AREA EVALUATI,ON: " , ",,' , **.
";,~",;,,," ':",..," "0;>""":':':"'" ""-,
"Decimal Fraction S~il GroupI>~W:â~'~;~~~}tif:~~i1~~:":)J'::
Decimal Fraction Soil Group B = :000 ""'," '>:
':",';
,.
Decimal Fraction Soil Group C = .000
Decimal Fraction Soil Group D = 1.000
RURAL (lots> 112 acre) runoff coefficient = .4500
Area Type is: RURAL (Greater than 1/2 Acre)
Time of concentration computed by the Natural
Watersheds nomograph, (App. X-A)
TC = [11.9*Length(Mi)^3)/(Elevation Change)]^.385*60(MIN/HR)
+ 10 min.
Initial Subarea Flow Dist. = 287.00
Highest Elevation = 333.00
Lowest Elevation = 304.00
Elevation Difference = 29.00
TC = [(11.9* .0544**3)/( 29.00)]**..385 = 1.474
+ 10 Min. = 11.474 Min.
100.00 Year Rainfall Intensity(In./Hr.) = 4.163
Subarea(Acres) = .38. Subarea Runoff(CFS) =
Total Area(Acres) = .38 Total Runoff(CFS) =
TC(MIN) = 11.47
.71
.71
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 17.000 to Point/Station 18.000
**. CONFLUENCE OF MINOR STREAMS ...
... Compute Various Confluenced Flow Values ...
- __n - - - - --- 00 ---- - --- n - n______- - - 00 - --- --- _n n - - - - - - ---- n - n - - - - - - - - ---
100.00 Year Rainfall Intensity(In./Hr.) = 4.163
ALONG THE MAIN STREAM NUMBER: 1
The flow values used for the stream: 3 are:
Time of concentration(min.) = 11.47
Rainfall intensity (in./hrl) = 4.16
Total flow area (Acres) = .38
Total runoff (CFS) at confluence point =
Confluence information:
Stream runoff Time Intensity
Number (CFS) (min.) (inch/hour)
.71
__n___n_n______---______n____--_------------------------_--__n--n--_--
I .71
2 .95
3 .71
QSMX( 1) =
+1.000* 1.000*
+ 1.000* .921*
+ .976* 1.000*
2.281
QSMX(2) =
+ .948* 1.000*
+ 1.000* 1.000*
.925* 1.000*
2.284
11.92
12.94
11.47
4.062
3.852
4.163
.7)
1.0)
.7)
.7)
1.0)
.7)
QSMX(3) =
+1.000* .963*
+ 1.000* .886*
+ 1.000*1.000*
2.239
.7)
1.0)
.7)
Rainfall intensity and time of concentration
used for 3 streams.
Individual stream flow values are:
.71 .95 .71
Possible confluenced flow values are:
2.28 2.28. 2.24
Individual Stream Area values are:
.37 .53 .38
Computed confluence estimates are:
Runoff(CFS) = 2.28 Time(min.) = 12.943
Total main stream study area (Acres) = 1.28
End of computations.. ,
TOT AL STUDY AREA(ACRES) =
2.71
(3.
",. xi. ,
APPENDIX B
TABLES AND CHARTS)
(,
£G(j¡l(TION
Tc. (l/tL J) .385
lé a ¡¡me ,,/ concenlralion
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Zð I ADD TEN MINUTES TOj'
UCOMPl.JTED TIME OF CON-
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SAN 01 EGO COUNTY
DEPARTMENT OF SPECIAL DISTRtCT SERVICES
. -. DESIGN MANUAL .'. :"-.,:
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DATE !~/lI 1 '"; . APPENdIX' X-t'f~,
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APP.ENDI~ X- f" . .~
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. DATE
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HIGHWAY DESIGN MANUAL
810-11
Jnntinry,1981"""-'
(. -'--~
Figure 816.6A
Overland Time of
Concentration Curves
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C
L
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IY
f
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= Runoff Coefficient
= Overland Travel
Distance in feet
S = Slope in tt.ltt.
i To ;; Timea in minutes
.
:
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JNTENSITY-DUMTION DESIGN CHART
.. ,..f
*Not Applicable to Desert Reg19~
<
~. .
".!),: 15 20 30 40 50 1
:." ~'C_'~=~~~-"='~--"'-"'-'
2
3
4
5
6
APPENDIX: XI
IV-A-14i
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t, :..
TABLE 2
RUNOFF COEFFICIENTS (RATIONAL METHOD)
DEVELOPED AREAS (URBAN)
Coefficient. C
Soi I Group (1)
Land Use
A B C D
Residential:
Single Fami ly .40 .45 ,50 .55
Multi-Units .45 .50 .60 .70
Mobi Ie homes .45 .50 .55 .65
Rural (lots greater than 1/2 acre) .30 .35 .40 .45
Corrrnerci al (2) .70 .75 .80 .85
80% Impervious
Industrial (2) .80 .85 .90 .95
90% Impervious
\
NOTES:
(1) Soil Group ma."s are available at the offices of the Department of Public Works.
(2)Where actual conditions deviate si9n¡fican~ly from the tabulated impervious-
ness values of 8~4 or 9~~. the values given for coefficient C, may be revised
by multiplying 8~4 or 90% by the ratio of actual imperviousness to the
tabulated 'imperviousness. However, in no case shall the final coefficient
be less than '0.50. For example: Consid~r commercial property on Dsoi I,group.
Actual fmpervious~ess
. 50%
Tabulated imperviousness . 8~k
Revised C . 50 x 0.85 . 0.53
80
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APPENDIX IX-B - 1,1
. Rev. S/81 , I
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Average Values of Roughness Coefficien~ (Manning's n)
1.
Type of Waterway
Closed Conduits (1)
2.
(
3.
Steel (not lined)
Cast Iron
Aluminum
Corrugated Metal
Corrugated Metal
Corrugated Metal
Corrugated f-Ietal
Concrete RCP
Clay (sewer)
Asbestos Cement~ Pv~
Dr~in Tile (terra cotta)
Cast-in-place Pipe
Reinforced Concrete Box
(not lined~
(2) (smooth asphalt quarterlining)
(2) (smoo~h asphalt half lining)
(smooth asphalt full lining)
Open Channels (1)
a.
Unlined
Clay Loam
Sand
b,
Revetted
Gravel
Rock
Pipe' and Wire
Sacked Concrete
c. Lined,
Codfrete (poured)
Air\: Blown Mortar (3)
Asphaltic Concrete or Bituminous Plant Mix
d.
Veg~tated (5) ,
Grass lined, maintained
Gra~s and Weeds
Grass liriedwith concrete low flow channel
Pavement and Gutters (1)
I
Concrete
'Bituminous (p~ant-mixed)
- -
. ,
.~~~ ;~:;-;::+'" .
Roughness
Coefficient (n)
0.015
0.015
.021
0.024 .
J.021
0.018
0.012
0.012
0.013
0.011
0.015
0.015
0.014
0.023
0.020
0.030
0.0..0
0.025
0.025
0.014
0.016
0.018
. .035
.045
- .032
0.015
0.016
.
.' ".
t ,APP~~DIX ~V~i ^-
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c,\?\4TY< OF SAN, D,IEGO
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FLOOD'CONTROL
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, u.s. DEPARTaIENir OF CO:.tMERCE
" NATlO:'A" OClAlcac AND AT. OSPIIEHIC AOi:I:'fISTRATION
.",aCU'LITUDII:I D_^-'fal, orriCK 0' II UROLOay. NATIONAL WEATIIER SERV1CI:
301
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DEPARTMENT OF SANITATION ~
fLOOD CONTROL .
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301
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151
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P,er-f'" lor
U.s. DEPARnn::Nlr OF COMMERCE
N"TIOKAL OCI!^="IC' AND ^,':JO!iI'IIEIUC l,O)lINI"rAATION
'PICIAL 'TUDIES BIIA:fCII. OrrICK 01' ...ioNOLOGY, HATIO:iA&. WI::ATIIER SEMVlCE
30'
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Emat F. Brater and Horace Williams King
HANDBOOK OF
I !
. '.
'-
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-
Table 7-14. Values of }\' for Circular Chnnn(\Js in tl1(' Formula
1
K'
Q = - d~~SI~
1L
D - depth of water
d 10: di311wtN of channel
DI
d I .00
_1__.
.01
.02
.03
.04
.05
.Oô
.07 I .08
.09
-.--.
,
.0 .00007'.00031 .00074'.00138'.00222 .QO328 .00455 .OOôO4'.OO77~
.1 .OOOc.7 .0118 ~0142 .OHi7 .0195 .022~ .0257 .02UI .0327 .03n6
_.2 .p.tOô .0448 .04n2 .0537 .058;) .003-1 .OO8ô .0738 .07H3 .0849
.3 .0907 .00ô6 .1027 .10SU .1153 .1218' .]284 .1352 .1420 .14HO
.4 .1561 .1633 .1705 .177U .1854 .1920 .2005 .2082 .2160 .2238
.5 .232 .239 .247 .255 .2c.3 .271 .279 .287 .295 .303
.6 .311 .319 .327 .335 ,343 .350 .358 .366' .373 .380
.7 .388 :395 ,402 .-Ion .416 ,422 .429 .435 ,441 .447
.8 ..as6 .458' .463 1.468 .473 .477 .481 .485 ,488 .491
.9 .49-1 .496 .497 .498 .498 .498 .496..\~ .494 .489 .483
.
1.0 .463
.
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APPENDIX
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( 4 .
HYDROLOGY MAP)
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