HomeMy WebLinkAboutCT 06-17; El Camino Terrace Parcel 3 of Map No 18059; Hydrology Study El Camino Terrace Parcel 3; 2009-07-06K&S K&S ENGINEERING
Planning Engineering Surveying
HYDROLOGY STUD Y
FOR:
EL CAMINO TERRACE
PARCEL 3 OF PARCEL MAP No. 18059
CARLSBAD, CA
Prepared By:
K&S Engineering
7801 Mission Center Court, Suite 100
San Diego, CA 92108
Prepared For:
Tycoon Development Corporation
2371 Fenton Street
Chula Vista, CA 91914
July 26, 2006
&S Job No 05-062
DATE
7801 Mission Center Court, Suite 100 • Son Diego, California 92108 • (619) 296-5565 • Fax (619) 296 5564
TABLE OF CONTENTS
1. HYDROLOGY DESIGN MODELS
2. INTRODUCTION
3. HYDROLOGIC CALCULATIONS APPENDIX A
4. TABLES AND CHARTS APPENDIX B
5. HYDROLOGY MAP APPENDIX C
6. REFERENCE MATERIAL APPENDIX D
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 (DMENSIONLESS)
I = RAINFALL INTENSITY IN INCHES/HOUR
A = TRIBUTARY DRAINAGE AREA IN ACRES
*1 ACRE INCHES/HOUR = 1.008 CUBIC FEET/SEC
THE OVERLAND METHOD IS ALSO USED IN THIS HYDROLOGY STUDY;
THE URBAN AREAS OVERLAND FORMULA IS AS FOLLOWS:
T=[ 1.8( 1.1 -C)(L)( 5))]/[S( 100)]333
L = LENGTH OF WATERSHED
C = COEFFICIENT OF RUNOFF
T = TIME IN MINUTES
S = DIFFERENCE IN ELEVATION DIVIDED BY DE LENGTH OF WATERSHED
B. DESIGN CRITERIA
- FREQUENCY, 100 YEAR STORM.
- LAND USE PER SPECIFIC PLAN AND TENTATIVE MAP.
- RAIN FALL INTENSITY PER COUNTY OF SAN DIEGO 2003, HYDROLOGY DESIGN
MANUAL.
C. REFERENCES
- COUNTY OF SAN DIEGO 2003, HYDROLOGY MANUAL.
- COUNTY OF SAN DIEGO 1992 REGIONAL STANDARD DRAWING.
- HAND BOOK OF HYDRAULICS BY BRATER & KING, SIXTH EDITION.
2. INTRODUCTION
A. EXISTING CONDITION
THE EXISTING SITE CONSISTS OF ONE VACANT COMMERCIAL LOT ON THE
SOUTHEAST CORNER OF THE EL CAMINO REAL & COUGAR DRIVE
INTERSECTION IN THE CITY OF CARLSBAD (PARCEL 3 AS SHOWN ON
PARCEL MAP NO. 18059). THE LOT IS PARTIALLY GRADED WITH AN AC
DRIVEWAY THAT RUNS NORTH TO SOUTH ALONG THE EAST SIDE.
MOST OF THE LOT AREA (0.93 ACRES) CURRENTLY DRAINS TOWARDS AN
EXISTING STORM DRAIN CATCH BASIN AND 12" PVC PIPE LOCATED ON THE
NORTHEAST AREA, GENERATING A RUNOFF AT THIS POINT OF Q100= 1.59
C.F.S.. THE EXISTING AC DRIVEWAY AND SOME SLOPE AREA (0.18 ACRES)
DRAIN TOWARDS AN EXISTING CURB INLET LOCATED ON THE MID-
EASTERLY AREA OF THE LOT, GENERATING Q100= 0.36 C.F.S.. THE REST OF
THE UNDEVELOPED LOT DRAINS TOWARDS BOTH STREETS EL CAMINO
REAL AND COUGAR DRIVE, THE SUPERFICIAL RUNOFF FOR THIS AREA IS A
TOTAL OF Q100= 0.50 C.F.S.
B. PROPOSED CONDITION
THE PROPOSED DEVELOPMENT CONSISTS OF THE CONSTRUCTION OF ONE
COMMERCIAL BUILDING WITH DRIVE AISLE AND PARKING.
STORM RUNOFF WILL BE COLLECTED BY PRIVATE INLETS AND PRIVATE
STORM DRAIN PIPES. THE PRIVATE STORM DRAIN SYSTEM WILL BE
CONNECTED TO THE EXISTING STORM DRAIN SYSTEM LOCATED WITHIN
THE NORTHEAST AREA OF THE SITE.
MOST OF THE SITE AREA DRAINS TOWARDS A PROPOSED CURB INLET
LOCATED NEAR THE NORTHEAST CORNER OF THE DEVELOPMENT WHERE
IT CONNECTS TO THE EXISTING 12" PVC PIPE ; AT THIS POINT THE
PROPOSED CONDITION WILL GENERATE A RUN-OFF OF 5.72 C.F.S.
THE PROPOSED DRIVEWAY/PARKING AREA (SOUTH EAST AREA) DRAINS
TOWARDS THE EXISTING CURB INLET LOCATED AT THE MID-EASTERLY
POINT OF THE SITE 'S A.C. DRIVEWAY. THE PROPOSED CONDITION RUNOFF
AT THIS POINT IS 1.09 C.F.S.
THE REST OF THE SITE WILL DRAIN TOWARDS BOTH STREETS EL CAMINO
REAL AND COUGAR DRIVE, THE SUPERFICIAL RUNOFF FOR THIS AREA IS A
TOTAL OF Q100= 0.30 C.F.S.
C. STORM WATER QUALITY
TO ADDRESS WATER QUALITY FOR THE PROJECT, BMPS WILL BE
IMPLEMENTED DURING CONSTRUCTION AND POST CONSTRUCTION PHASES. PER
SECTION II, TABLE 1 OF THE STANDARDS, THE PROJECT IS BEST DESCRIBED AS
BELONGING TO THE PARKING LOT CATEGORY.
AS A PRIORITY PROJECT, THIS CATEGORY REQUIRES APPROPRIATE BMPS FROM
THE APPLICABLE CATEGORIES BELOW OR EQUIVALENTS AS IDENTIFIED IN
APPENDIX C OF THE STANDARDS:
• SITE DESIGN BMPS
• SOURCE CONTROL BMPS
• BMPS APPLICABLE TO SPECIFIC CATEGORIES:
1. SURFACE PARKING AREAS
DESPITE THE FACT THAT THE PROJECT DOESN'T MEET THE CRITERIA FOR THE
COMMERCIAL DEVELOPMENT CATEGORY, THOSE SPECIFIC CATEGORY BMPS
ARE ADDRESSED. THESE ARE IDENTIFIED AS:
1. DOCK AREAS
2. MAINTENANCE BAYS
3. VEHICLE WASH AREAS
4. EQUIPMENT WASH AREAS
IN ADDITION, INCORPORATED INTO THE PROJECT ARE APPROPRIATE SITE
DESIGN AND SOURCE CONTROL BMPS FOR STANDARD PROJECTS.
FOR MORE DETAILS ON STORM WATER QUALITY FOR THE PROPOSED SITE,
PLEASE REFER TO THE STORM WATER MANAGEMENT AND STORM WATER
MAINTENANCE PLAN.
D. SUMMARY
THERE IS AN INCREASE IN RUNOFF FROM THE EXISTING TO THE PROPOSED
CONDITION OF 4.66 C.F.S., THIS IS DUE SOLELY TO INCREASING THE "C"
VALUE FROM EXISTING TO COMMERCIAL DEVELOPMENT.
THE INCREASE OF RUNOFF WILL NOT HAVE ANY NEGATIVE IMPACT SINCE
THE EXISTING IMPROVEMENTS WERE DESIGNED TO HANDLE THE
ULTIMATE FLOW FOR THE PROPOSED ZONING, SEE PRELIMINARY
HYDROLOGY STUDY PREPARED BY PACIFIC LAND SURVEYING, DATED
OCTOBER 8, 1996 (APPENDIX D.)
APPENDIX A
(3. HYDROLOGIC CALCULATIONS)
EXISTING CONDITION HYDROLOGY (100 YEAR STORM)
EL CAMINO TERRACE J.N.05-062
San Diego County Rational Hydrology Program
CIVILCADD/C1VILDESIGN Engineering Software,(c) 1991-2004 Version 7.4
Rational method hydrology program based on
San Diego County Flood Control Division 2003 hydrology manual
Rational Hydrology Study Date: 07/25/06
********* Hydrology Study Control Information **********
Program License Serial Number 4035
Rational hydrology study storm event year is 100.0
English (in-lb) input data Units used
Map data precipitation entered:
6 hour, precipitation(inches) = 2.700
24 hour precipitation(inches) = 4.800
P6/P24 = 56.3%
San Diego hydrology manual 'C values used
Process from Point/Station 1.000 to Point/Station 2.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN ]
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub-Area C Value = 0.350
Initial subarea total flow distance = 163.000(Ft.)
Highest elevation = 271.000(Ft.)
Lowest elevation = 264.000(Ft.)
Elevation difference = 7.000(Ft.) Slope = 4.294 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 4.29 %, in a development type of
Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 8.31 minutes
TC = [ 1.8*( 1.1 -C)*distance(Ft.)A.5)/(% slopeA( 1 /3)]
TC = [1.8*(l.l-0.3500)*(100.000A.5)/( 4.294A(l/3)]= 8.31
The initial area total distance of 163.00 (Ft.) entered leaves a
remaining distance of 63.00 (Ft.)
Using Figure 3-4, the travel time for this distance is 0.64 minutes
for a distance of 63.00 (Ft.) and a slope of 4.29 %
with an elevation difference of 2.71 (Ft.) from the end of the top area
Tt = [11.9*length(Mi)A3)/(elevation change(Ft.))]A.385 *60(min/hr)
= 0.637 Minutes
Tt=[(II.9*0.0119A3)/( 2.71)]A.385= 0.64
Total initial area Ti = 8.31 minutes from Figure 3-3 formula plus
0.64 minutes from the Figure 3-4 formula = 8.94 minutes
Rainfall intensity (I) = 4.889(ln/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.350
Subarea runoff = 1.591(CFS)
Total initial stream area = 0.930(Ac.)
+++++++++4
Process from Point/Station 3.000 to Point/Station 4.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN ]
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub-Area C Value = 0.350
Initial subarea total flow distance = 124.000(Ft.)
Highest elevation = 265.500(Ft.)
Lowest elevation = 256.000(Ft.)
Elevation difference = 9.500(Ft.) Slope = 7.661 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 7.66 %, in a development type of
Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 6.85 minutes
TC = [1.8*(l.l-C)*distance(Ft.)A.5)/(% slopeA(l/3)]
TC = [1.8*(1.1-0.3500)*( 100.000A.5)/( 7.660A(l/3)]= 6.85
The initial area total distance of 124.00 (Ft.) entered leaves a
remaining distance of 24.00 (Ft.)
Using Figure 3-4, the travel time for this distance is 0.24 minutes
for a distance of 24.00 (Ft.) and a slope of 7.66 %
with an elevation difference of 1.84(Ft.) from the end of the top area
Tt = [11.9*length(Mi)A3)/(elevation change(Ft.))]A.385 *60(min/hr)
= 0.243 Minutes
Tt=[(11.9*0.0045A3)/( 1.84)]A.385= 0.24
Total initial area Ti = 6.85 minutes from Figure 3-3 formula plus
0.24 minutes from the Figure 3-4 formula = 7.09 minutes
Rainfall intensity (I) = 5.678(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.350
Subarea runoff = 0.358(CFS)
Total initial stream area = 0.180(Ac.)
++++++++++++++++++++++++++++++++++++++++++++4
Process from Point/Station 5.000 to Point/Station 6.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN ]
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub-Area C Value = 0.350
Initial subarea total flow distance = 153.000(Ft.)
Highest elevation = 284.000(Ft.)
Lowest elevation = 275.000(Ft.)
Elevation difference = 9.000(Ft.) Slope = 5.882 %
INITIAL AREA TIME OF CONCENTRATION CALCULATIONS:
The maximum overland flow distance is 100.00 (Ft)
for the top area slope value of 5.88 %, in a development type of
Permanent Open Space
In Accordance With Figure 3-3
Initial Area Time of Concentration = 7.48 minutes
TC = [ 1.8*( 1.1 -C)*distance(Ft.)A.5)/(% slopeA( 1 /3)]
TC = [1.8*(1.1-0.3500)*( 100.000A.5)/( 5.880A(l/3)]= 7.48
The initial area total distance of 153.00 (Ft.) entered leaves a
remaining distance of 53.00 (Ft.)
Using Figure 3-4, the travel time for this distance is 0.49 minutes
for a distance of 53.00 (Ft.) and a slope of 5.88 %
with an elevation difference of 3.12(Ft.) from the end of the top area
Tt = [1 l.9*length(Mi)A3)/(elevation change(Ft.))]A.385 *60(min/hr)
= 0.494 Minutes
Tt=[(11.9*0.0100A3)/( 3.12)]A.385= 0.49
Total initial area Ti = 7.48 minutes from Figure 3-3 formula plus
0.49 minutes from the Figure 3-4 formula = 7.97 minutes
Rainfall intensity (I) = 5.265(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.350
Subarea runoff = 0.147(CFS)
Total initial stream area = 0.080(Ac.)
Process from Point/Station 7.000 to Point/Station 8.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[UNDISTURBED NATURAL TERRAIN ]
(Permanent Open Space )
Impervious value, Ai = 0.000
Sub-Area C Value = 0.350
Initial subarea total flow distance = 42.000(Ft.)
Highest elevation = 265.000(Ft.)
Lowest elevation = 250.600(Ft.)
Elevation difference = 14.400(Ft.) Slope = 34.286 %
USER ENTRY OF INITIAL AREA TIME OF CONCENTRATION
Time of Concentration = 5.00 minutes
Rainfall intensity (I) = 7.114(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.350
Subarea runoff = 0.349(CFS)
Total in itial stream area = 0.140(Ac.)
End of computations, total study area = 1.330 (Ac.)
PROPOSED CONDITION HYDROLOGY 100 YEAR STORM
ELCAMINO TERRACE
San Diego County Rational Hydrology Program
CIVILCADD/CIVILDESIGN Engineering Software,(c) 1991-2004 Version 7.4
Rational method hydrology program based on
San Diego County Flood Control Division 2003 hydrology manual
Rational Hydrology Study Date: 07/24/06
********* Hydrology Study Control Information **********
Program License Serial Number 4035
Rational hydrology study storm event year is 100.0
English (in-lb) input data Units used
Map data precipitation entered:
6 hour, precipitation(inches) = 2.700
24 hour precipitation(inches) = 4.800
P6/P24 = 56.3%
San Diego hydrology manual 'C' values used
Process from Point/Station 1.000 to Point/Station 2.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type ]
(Office Professional )
Impervious value, Ai = 0.900
Sub-Area C Value = 0.850
Initial subarea total flow distance = 61.000(Ft.)
Highest elevation = 270.000(Ft.)
Lowest elevation = 269.530(Ft.)
Elevation difference = 0.470(Ft.) Slope = 0.770 %
USER ENTRY OF INITIAL AREA TIME OF CONCENTRATION
Time of Concentration = 5.00 minutes
Rainfall intensity (I) = 7.114(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.850
Subarea runoff = 0.967(CFS)
Total initial stream area = 0.160(Ac.)
Process from Point/Station 2.000 to Point/Station 3.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 267.770(Ft.)
Downstream point/station elevation = 266.220(Ft.)
Pipe length = 156.75(Ft.) Manning's N = 0.013
No. of pipes =1 Required pipe flow = 0.967(CFS)
Given pipe size = 8.00(In.)
Calculated individual pipe flow = 0.967(CFS)
Normal flow depth in pipe = 5.44(In.)
Flow top width inside pipe = 7.47(ln.)
Critical Depth = 5.60(ln.)
Pipe flow velocity = 3.83(Ft/s)
Travel time through pipe = 0.68 min.
Time of concentration (TC) = 5.68 min.
Process from Point/Station 2.000 to Point/Station 3.000
**** SUBAREA FLOW ADDITION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type ]
(Office Professional )
Impervious value, Ai = 0.900
Sub-Area C Value = 0.850
Time of concentration = 5.68 min.
Rainfall intensity = 6.550(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.850 CA = 0.213
Subarea runoff = 0.424(CFS) for 0.090(Ac.)
Total runoff = 1.392(CFS)Total area = 0.250(Ac.)
-H-+++++++++++++++++++++++++++++++++++++++++++++
Process from Point/Station 3.000 to Point/Station 4.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 266.220(Ft.)
Downstream point/station elevation = 262.000(Ft.)
Pipe length = 41.71(Ft.) Manning's N = 0.013
No. of pipes =1 Required pipe flow = 1.392(CFS)
Given pipe size = 8.00(In.)
Calculated individual pipe flow = 1.392(CFS)
Normal flow depth in pipe = 3.33(ln.)
Flow top width inside pipe = 7.89(In.)
Critical Depth = 6.66(In.)
Pipe flow velocity = 10.13(Ft/s)
Travel time through pipe = 0.07 min.
Time of concentration (TC) = 5.75 min.
Process from Point/Station 3.000 to Point/Station 4.000
**** SUBAREA FLOW ADDITION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type ]
(Office Professional )
Impervious value, Ai = 0.900
Sub-Area C Value = 0.850
Time of concentration = 5.75 min.
Rainfall intensity = 6.500(ln/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.850 CA = 0.255
Subarea runoff = 0.266(CFS) for 0.050(Ac.)
Total runoff = 1.657(CFS)Total area= 0.300(Ac.)
Process from Point/Station 4.000 to Point/Station 5.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 262.000(Ft.)
Downstream point/station elevation = 257.750(Ft.)
Pipelength= 180.25(Ft.) Manning's N = 0.013
No. of pipes =1 Required pipe flow = 1.657(CFS)
Given pipe size = 8.00(In.)
Calculated individual pipe flow = 1.657(CFS)
Normal flow depth in pipe = 5.89(In.)
Flow top width inside pipe = 7.05(In.)
Critical Depth = 7.13(In.)
Pipe flow velocity = 6.01(Ft/s)
Travel time through pipe = 0.50 min.
Time of concentration (TC) = 6.25 min.
Process from Point/Station 4.000 to Point/Station 5.000
**** SUBAREA FLOW ADDITION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type ]
(Office Professional )
Impervious value, Ai = 0.900
Sub-Area C Value = 0.850
Time of concentration = 6.25 min.
Rainfall intensity = 6.160(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.850 CA = 0.323
Subarea runoff = 0.332(CFS) for 0.080(Ac.)
Total runoff= 1.990(CFS)Total area= 0.380(Ac.)
Process from Point/Station 5.000 to Point/Station 6.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 257.750(Ft.)
Downstream point/station elevation = 256.930(Ft.)
Pipe length = 23.26(Ft.) Manning's N = 0.013
No. of pipes =1 Required pipe flow = 1.990(CFS)
Given pipe size = 12.00(In.)
Calculated individual pipe flow = 1.990(CFS)
Normal flow depth in pipe = 4.49(In.)
Flow top width inside pipe = 11.61 (In.)
Critical Depth = 7.23(In.)
Pipe flow velocity = 7.43(Ft/s)
Travel time through pipe = 0.05 min.
Time of concentration (TC) = 6.30 min.
Process from Point/Station 5.000 to Point/Station 6.000
**** SUBAREA FLOW ADDITION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D= 1.000
[COMMERCIAL area type ]
(Office Professional )
Impervious value, Ai = 0.900
Sub-Area C Value = 0.850
Time of concentration = 6.30 min.
Rainfall intensity = 6.127(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.850 CA= 0.901
Subarea runoff = 3.53 l(CFS) for 0.680(Ac.)
Total runoff = 5.520(CFS)Total area= 1.060(Ac.)
Process from Point/Station 6.000 to Point/Station 7.000
**** PIPEFLOW TRAVEL TIME (User specified size) ****
Upstream point/station elevation = 248.500(Ft.)
Downstream point/station elevation = 246.120(Ft.)
Pipe length = ll.OO(Ft) Manning'sN = 0.013
No. of pipes =1 Required pipe flow = 5.520(CFS)
Given pipe size = 12.00(In.)
Calculated individual pipe flow = 5.520(CFS)
Normal flow depth in pipe = 4.77(In.)
Flow top width inside pipe =11.74(In.)
Critical Depth = 11.28(In.)
Pipe flow velocity = 18.98(Ft/s)
Travel time through pipe = 0.01 min.
Time of concentration (TC) = 6.31 min.
+++++++++1 I I I I I++++++++++++++++++++++++++++4
Process from Point/Station 6.000 to Point/Station 7.000
**** SUBAREA FLOW ADDITION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type ]
(Office Professional )
Impervious value, Ai = 0.900
Sub-Area C Value = 0.850
Time of concentration = 6.31 min.
Rainfall intensity = 6.121(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for total area
(Q=KCIA) is C = 0.850 CA = 0.935
Subarea runoff = 0.203(CFS) for 0.040(Ac.)
Total runoff= 5.723(CFS)Total area= 1.100(Ac.)
Process from Point/Station 8.000 to Point/Station 9.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type ]
(Office Professional )
Impervious value, Ai = 0.900
Sub-Area C Value = 0.850
Initial subarea total flow distance = !58.000(Ft.)
Highest elevation = 266.490(Ft.)
Lowest elevation = 254.000(Ft.)
Elevation difference = 12.490(Ft.) Slope = 7.905 %
USER ENTRY OF INITIAL AREA TIME OF CONCENTRATION
Time of Concentration = 5.00 minutes
Rainfall intensity (I) = 7.114(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.850
Subarea runoff = 1.088(CFS)
Total initial stream area = 0.180(Ac.)
Process from Point/Station 10.000 to Point/Station 11.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type ]
(Office Professional )
Impervious value, Ai = 0.900
Sub-Area C Value = 0.850
Initial subarea total flow distance = 65.000(Ft.)
Highest elevation = 265.000(Ft.)
Lowest elevation = 255.000(Ft.)
Elevation difference = lO.OOO(Ft) Slope = 15.385 %
USER ENTRY OF INITIAL AREA TIME OF CONCENTRATION
Time of Concentration = 5.00 minutes
Rainfall intensity (I) = 7.114(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.850
Subarea runoff = 0.242(CFS)
Total initial stream area = 0.040(Ac.)
Process from Point/Station 12.000 to Point/Station 13.000
**** INITIAL AREA EVALUATION ****
Decimal fraction soil group A = 0.000
Decimal fraction soil group B = 0.000
Decimal fraction soil group C = 0.000
Decimal fraction soil group D = 1.000
[COMMERCIAL area type ]
(Office Professional )
Impervious value, Ai = 0.900
Sub-Area C Value = 0.850
Initial subarea total flow distance = 20.000(Ft.)
Highest elevation = 63.000(Ft.)
Lowest elevation = 56.000(Ft.)
Elevation difference = 7.000(Ft.) Slope = 35.000 %
USER ENTRY OF INITIAL AREA TIME OF CONCENTRATION
Time of Concentration = 5.00 minutes
Rainfall intensity (I) = 7.114(In/Hr) for a 100.0 year storm
Effective runoff coefficient used for area (Q=KCIA) is C = 0.850
Subarea runoff = 0.060(CFS)
Total initial stream area = 0.010(Ac.)
End of computations, total study area = 1.330 (Ac.)
APPENDIX B
(4. TABLES AND CHARTS)
I I f. I i III! if if if i|I 1 I 1 1 t I I I i I i i
REST ORIGINAL
•irijxlT'i;ffii!ti.rj
l!§Sfjtr r
I | !-i-4._....i>> j j ....
County of San Diego
Hydrology Manual
Rainfall Isopluvials
100 Year Rainfall Event • 6 Hours
Isopluvial (inches)
Vi HJ.I Sjn !>,(,.<-....r.J.'
o* UMCMM>»MUn*M>f*ll«UKM*MiraCU>WIH
E ~~
303 Miles
i .1 i I i i 1 I I i i i i I 1 I, I 1 I i I i t i I I i
BEST ORIGINAL
County of San Diego
Hydrology Manual
Rainfall Isopluvials
100 Year Rainfall Event - 24 Hours
Isopluvtal (inches)
BEST ORIGINAL
DP\V
*.\ ILv.: VIM l>ipiljniliJ!
uinow>t*«Ufr*MOmi«M ton 11 unrii ii
303 Miles
i 1 t i * i t I i i i i i a i t i i i i i a i i
San Diego County Hydrology Manual
Date: June 2003
BEST ORIGINAL
Section:
Page:3
6 of 26
„•»
Table 3-1
RUNOFF COEFFICIENTS FOR URBAN AREAS
Land Use
NRCS Elements
Undisturbed Natural Terrain (Natural)
Low Density Residential (LDR)
Low Density Residential (LDR)
Low Density Residential (LDR)
Medium Density Residential (MDR)
Medium Density Residential (MDR)
Medium Density Residential (MDR)
Medium Density Residential (MDR)
High Density Residential (HDR)
High Density Residential (HDR)
Commercial/Industrial (N. Com)
Commercial/Industrial (G. Com)
Commercial/Industrial (O.P. Com)
Commercial/Industrial (Limited I.)
Commercial/Industrial (General I.)
County Elements
Permanent Open Space
Residential, 1.0 DU/A or less
Residential, 2.0 DU/A or less
Residential, 2.9 DU/A or less
Residential, 4.3 DU/A or less
Residential, 7.3 DU/A or less
Residential, 10.9 DU/A or less
Residential, 14.5 DU/A or less
Residential, 24.0 DU/A or less
Residential, 43.0 DU/A or less
Neighborhood Commercial
General Commercial
Office Professional/Commercial
Limited Industrial
General Industrial
Runoff Coefficient "C"
Soil Type
% IMPER.
0*
10
20
25
30
40
45
50
65
80
80
85
90
90
95
A
0.20
0.27
0.34
0.38
0.41
0.48
0.52
0.55
0.66
0.76
0.76
0.80
0.83
0.83
0.87
B
0.25
0.32
0.38
0.41
0.45
0.51
0.54
0.58
0.67
0.77
0.77
0.80
0.84
0.84
0.87
C
0.30
0.36
0.42
0.45
0.48
0.54
0.57
0.60
0.69
0.78
0.78
0.81
0.84
0.84
0.87
D
0.35
0.41
0.46
0.49
0.52
0.57
0.60
0.63
0.71
0.79
0.79
0.82
0.85
0.85
0.87
*The values associated with 0% impervious may be used for direct calculation of the runoff coefficient as described in Section 3.1.2 (representing the pervious runoff
coefficient, Cp, for the soil type), or for areas that will remain undisturbed in perpetuity. Justification must be given that the area will remain natural forever (e.g., the area
is located in Cleveland National Forest).
DU/A - dwelling units per acre
NRCS •• National Resources Conservation Service
3-6
Watershed Divide.
Watershed
Divide
Design Point
(Watershed Outlet)
Area "A" = Area "B"
SOURCE: California Division of Highways (1941) and Wrplch (1940)
FIGURE
Computation of Effective Slope for Natural Watersheds 3-5
San Diego County Hydrology Manual
Date: June 2003
Section:
Page:
3
12 of 26
Note that the Initial Time of Concentration should be reflective of the general land-use at the
upstream end of a drainage basin. A single lot with an area of two or less acres does not have
a significant effect where the drainage basin area is 20 to 600 acres.
Table 3-2 provides limits of the length (Maximum Length (LM)) of sheet flow to be used in
hydrology studies. Initial T< values based on average C values for the Land Use Element are
also included. These values can be used in planning and design applications as described
below. Exceptions may be approved by the "Regulating Agency" when submitted with a
detailed study.
Table 3-2 BEST ORIGINAL
MAXIMUM OVERLAND FLOW LENGTH (LM)
& INITIAL TIME OF CONCENTRATION (Tj)
Element*DU/
Acre
"Jatural
LDR
LDR
LDR
MDR.
MDR
MDR
MDR
HDR
HDR
N. Com
G. Com
o.pycom
Limited
General
-M
2.9
4.3
7.3
10.9
14.5
24
43
.5%
M
50 13.2
50 12.2
50 11.3
50 10.7
50 10.2
50 9.2
50 8.7
50 8.2
50 6.7
50 5.3
50 5.
50 4.
50 4.
50 4
1%
-M
70 12.5
70 11.5
70 10.5
70 10.0
70 9.6
65 8.4
65 7.9
65 7.4
65 6.1
65 4.7
60 4.5
60 4.
60 3.
60 3.
50 3.7 60 3.2 70 2
2%
85
85
85
85
80
80
80
80
75
75
75
75
70
7
0.9
0.0
9.2
8.8
8.1
7.4
6.9
6.5
5.1
4.0
4.
3.
3.
3%5%10%
M
00
00
100
95
95
95
90
90
90
85
85
85
8
8
8
LM LM
0.3 100 8.7 100 6.9
9.5 100 8.0 100 6.4
8.8 100 7.4 100 5.8
8.1 100 7.0 100 5.6
7.8 100 6.7 100 5.3
7.0 100 6.0 100 4.8
6.4 100 5.7 100 4.5
6.0 100 5.4 100 4.3
4.9 95 4.3 100 3.5
3.8 95 3.4 100 2.7
3.8 95 3.4 100 2.7
3.4 90 2.9 100 2.4
2.9 90 2.6 100 2
2.9 90 2.6 100 2
2.6 90 2.3 100 1
*See Table 3-1 for more detailed description
r
c
3-12
Average Values of Roughness Coefficient (Manning's n)
Roughness
Type of Waterway Coefficient (n)
1. Closed Conduits (1)
Steel (not lined) 0.015
Cast Iron 0.015
Aluminum -021
Corrugated Metal (not lined) ' 0.024 •
Corrugated Metal (2) (smooth asphalt quarterlining) 0.021
Corrugated Metal (2) (smooth asphalt half lining) 0.018
Corrugated Metal (smooth asphalt full lining) 0.012
Concrete RCP 0-012
Clay (sewer) 0.013
Asbestos Cement-^ Pv<^- 0.011
Drain Tile (terra cotta) 0.015
Cast-in-placp Pipe 0.015
Reinforced Concrete Box 0.014
2. Open Channels (1)
a. Unlined
Clay Loam 0.023
Sand 0.020
b. Revetted
Gravel 0-030
Rock 0.040
Pipe' and Wire °-025
Sacked Concrete 0.025
c. Lined
Concrete (poured) 0.014
Airl Blown Mortar (3) °-01J
Asphaltic Concrete or Bituminous Plant Mix 0.018
d. Vegetated (5)
Grass lined, maintained -035
Grass and Weeds -°^5
Grass lined with concrete low flow channel .032
3. Pavement and Gutters (1)
t
Concrete . °-013
Bituminous (plant-mixed) 0.016
BEST ORIGINAL
APPENDIX XVI, A
-ii || || II II ki II II 11 II II II i ft l i l i
BEST ORIGINAL
= 70 Fee,1.8(1.1-C)V5"
FIGURE
3-3
EQUATION: V = 1.49 R"i s"*n
-0.3W.J
0.2
0.15
•0.10
•0.09
•0.08
-0.07
-0.06
J
03 JjfJ
o:o
t &
-0.05 t\ ID
• 0.04
.0.03
• 0.02
1
•5 to.oi
£. P 0.009
.£ t 0.008
UJ f- 0.007
Q f 0.006
•0.005
•0.003
• 0.002
•0.001
•0.0009
•0.0008
•0.0007
• 0.0006
•0.0005
• 0.0004
.0.0003
.0,8
• 0.9
.1.0
ata>
cl
W
•6
• 7
• 8
9
10
20
.50
•40
0
20
0)U)
!
• 1.0
-0.9
:0.8
•0.7
•0.6
-0.5
.0.01
-0.02
<rU.o3
II
§1-0.04
wf
Of- 0.06
-0.08
-0.09
-0.10
• 0.2
-0.3
-0.4
GENERAL SOLUTION
SOURCE: USDOT. FHWA. HDS-3 (1961)
Manning's Equation Nomograph
FIGURE
3-7
Intensity (m/hr)
6-Hour Precipitation (in)
Duration (min)
5 6 7 8 9 10 15 20 30 40 50 1
Minutes
Duration
Directions for Application:
(1) From precipitation maps determine 6 hr and 24 hr amounts
for the selected frequency. These maps are Included in the
County Hydrology Manual (10, 50, and 100 yr maps Induded
in the Design and Procedure Manual).
(2) Adjust 6 hr precipitation (if necessary) so that it is within
the range of 45% to 65% of the 24 hr precipitation (not
applicaple to Desert).
(3) Plot 6 hr precipitation on the right side of the chart.
(4) Draw a line through the point parallel lo the plotted lines.
(5) This line Is the intensity-duration curve for the location
being analyzed.
Application Form:
.j. (a) Selected frequency year
in.,P24 =
£ (c) Adjusted P6'2> = .
ETf (d) tx = min.
(e) I = in./hr.
-.•P24
in.
Note: This chart replaces the Intensily-Duration-Frequency
curves used since 1965.
pC, J...1 .Duration ! 1
1
1
"20
25
30
4(
SO
60
90
120
150
ISO
340
300
360
' 1.5 ! 2 ." 2.5 ' 3 -'. 3.5
1 ' 1 1 ,' 1 ! 1
2.63 1 3. 95 527 6.59.7909.22
2.12
1.68
1.30
1.08
0.93
0.83
0.69
0.60
0.53
0.41
0.34
0.29
026
0.22
0.19
0.17
3.181 4.24' 5.30 '6.36 17.42
275313.37' 4.2l"'6.0Sl5.90
t.95;2.S9' 3.24i3.89l454
1.62 2'J5''"2!69T3.23r3.77
1.40
1.24
1.87: 2.33.280
1.66 2.071249
U27
290
1.03 1.38 1.7212.0712.41
0.90! 1.191 1.49 |1.79
080
0.61
O.S1
0.44
0.30
0.33
>.2fl
0.2S
1. 08 j 1.33
0.8?; 1.02
0.68
0.69
0.52
0.43
6.36
0.33
0.85
0.73
0.08
0.54
0.47
0.42
1.59
1.23
1.02
0.68
0.78
0.65
0.58
0.90
2.09
1.88
1.43
1.19
1.03
0.81
0.78
ft.86
0.68
I ,
4 4~.5 """ 5
I : I 1
10.54 11.86 I3.i;
8.48 ! 9.54 , 10.60
6.74 7 58 ' 8.42
5.19 j 5.841*6.49
4.31 "I 4.85 '5.39
3.73] 4.20 4.67
332
2.76
2.39
2.12
1.63
1.36
1.18
1.04
0.87
0.7J
0.87
373 ! 4 IS
3 10 ' 3.45
2.69 ! 2.98
2.39
1.84
1.53
1.32
1.18a »e
OM
0.79
2.65
2.04
1.70
1.47
IJ1
1X»a»4
0.84
5.5 j 6
ill)
14.49! 15.81
11.66
927
7.13
5.93
5.13
456
3.79
3.28
2.82
Z25
1.67
12.72
10.11
7.78
6~46
5.60
498
413
358
3.18
2.45
2.04
1.62IJ.78 J
.M4n.$7|
1.18 h JO 1
1.03 1.13 1
OKI 1.001
F I
Intensity-Duration Design Chart - Template BEST ORIGINAL
* i i i f 1 I 1 I 1
(Ill i I
APPENDIX C
(5. HYDROLOGY MAP)
EXISTING CONDITION
HYDROLOGY MAP 0100= 0.35C.F.S
EL CAMINO TERRACE SCALE: 1"= 30PARCEL 3 OF PARCEL MAP 18059
\ 0100= 0.15 C.F.S.r-" " "
(093 AC)
\\\ \
y
PROPOSED CONDITION
HYDROLOGY MAP
EL CAMINO TERRACE
PARCEL 3 OF PARCEL MAP 18059
Q1QQ=5J2C.F.S\
\%m I\\x
0100= 1.09 C.F.S
APPENDIX D
(6. REFERENCE MATERIAL)
JOB.PALMER WAY INDUSTRIAL PARK
PACIFIC LAND SU EYING
2180 Garnet Avenue, ouite 3K
SAN DIEGO, CALIFORNIA 92109
(619) 270-4918
FAX (619) 581-0402
SHEET NO.OF_
CALCULATED BY_
CHECKED BY
1"SCALE
C.R. DECK n4TP 10/8/96
PRELIMINARY HYDROIiOGY STUDY
PLEASE SEE THE ATTACHED 2 SHEET EXHIBIT THAT SHOWS THE 4 PARCELS CJF THIS
PROJECT. PARCELS 1 AND 2 SHALL BE DEVELOPED WITH A •COMMERCIAL BLDG> ON EACH.
PARCEL 3 IS ASSUMED TO BE ALSO DEVELOPED A ;COHMERCIAL BLD0,
FUTURE. PARCEL 4 IS TO REMAIN AS OPEN SPACE, NO CHANGE O
PLEASE REVIEWTHE FOLLOWING ESTIMATES.
DATA USED:1= 4.5 IN PER HR. | i !
RUNOFF COEF: FOR COMMERCIAll !.85
PARCEL AREA COEF.INTENSITY
HYDROLOGY
(AFTER) f
NEAR
OCCUR
PROPOSED!
I
"4"
(BEFORE1)
QIJOO j
1
2
.74 AC.
1.21 AC-
85 4.5 IN/HR 2^83 !CF U66 dFS
3 1.46 AC.
BEST ORIGINAL
4J63 JCF£
5 J58 :CFS
72 CFS
3.29 CFS
67 CFS
THIS TOTAL RUNOFF OF 13.04 CFS WILL BE REDUCED BY ±15Z DO TO THE
OF THIS PROJECT THAT SHEET FLOW TO THE EXISTING PUBLIC STREETS.!THEREFORE,
lirigi^FS WILL COLLECT INTO A PROPOSED ON-SITE PRIVATE STORM DRAlri SYSTEM
AND FLOW NORTHEASTERLY TO A POINT OF CONNECTION WITH AN EXISTING CURB IN-
LET JUST NORTH OF PARCEL 1. : |
THE NET CHANGE AFTER DEVELOPMENT IS A FUNCTION OF THE ASSUMED RUNOFF COEF.
.85 VS. w50 (FOR VACANT LAND). COLUMN "A" ABOVE GIVES THESE BEFOR^ DEVELOPMENT
ESTIMATES. : i
THE RUNOFF FOR PARCEL 4 IS 14.3 CFS, WHICH WILL CONTINUE TO SHEET FLOW TO
THE EXISTING CANYON.
PREPARED BY:
CHARLES R. DECK, PE
if*uxn/ACB»/. M . dou u«i OKII loom PHCK lou ma tun?«f»o