HomeMy WebLinkAboutCT 81-10; Carlsbad Research Center Lot 29; Drainage Study; 1991-07-29JULY 29, 1991
151/91/00 FF
7/3//+7/
CHARLES S. KAHR R.C.E. 23907
REFISTRATION EXPIRES 12/31/93 DATE
KAHR AND ASSOCIATES
CARLSBAD, CA 92006 5600 AVENIDA ENCINAS, SUITE 133
(619) 431-9301
WS/151-91
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L.WD USE
RUKOFF COEFFICIENTS (RATIONAL METHOD)
Coefficient, C
Soil Group (1)
Undeveloped
Residential:
Rura 1
Single Family
Multi-Units
Mobile Homes 42)
Commercial (2)
80% Impervious
- 4 8 C 0
.30 .35 . .40 .45
- " -
.40 .45 .so .55
.45 .50 .60 .TO
.45 .so .55 .55
. io . 75 t80 .S5
Industrial (2) .80 .85 .90
90% Impervious ..
NOTES :
(1) Obtain soil group from maps on file with the Department of Sanitation.
and Flood Control.
(2) Where actual conditions deviate significantly from the tabulated
imperviousness values of 80% or 90%, the values given for coefficiezt
C, may be revised by multiplying 80% 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: Consider
commercial property on D soil group.
Actual imperviousness = 50%
Tabulated imperviousness = SO!;
Revised C = X 0.85 = 0.55 ET
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