GENERAL30616

• Permit No: M1989065
• IBM Index Class Name: General Documents
• Doc Name: CUHP MODEL WILLOW CREEK CROSSING
• Media Type: D
• Archive: No

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.~ .C.D. CUHF' F:UNOFF ANALYSIS EXECUTED DN DATE 2/15/89 1 pF 2
L.~'E/F'C VERSTUN MODIFIED ItJ JANUARY 198:,
ASIN ID: WILLOW -- BASIN COMMENT: WILLOW CF:EEk; WINk;LER
F~4 OF EASIN LENGTH OF EASIN DIST TO CENTF:DID IMPERVIOUS AREA SLOPE
(SC!MI) (MI) (MI) (PCT) (FT/FTS
2.88 4.17 'c'.OU 2.00 .0230
COEFFICIENT COEFFICIENT
/REFL.ECTING TIMIE TO F'EAI<) (RELATED TO PEAk: RATE OF- RUNOFF)
.7.56 .391
CALCULATED UNIT HYDROGRAFH
~[ TO F'EAk; F'EAF: RATE OF RUNOFF UNIT HYDROGRAF' FEA!':: VOLUME OF RUNOFF
(MIN) (CFS/SQMI) (CFS> (AF)
' 60.39
_35.14
677.21
153.60
J~TI-I AT 50 = 128. MIN. WIDTH AT 75 = bb. MIN. K50 = .31 Ii75 = .42
RAINFALL LOSSES INPUT W/ FASIN DATA
M PERVIOUS F:ET. _ .50 IN. MAX, IMPERVIOUS RET. _ .30 IN.
I'-iLTRATION = 3.00 IN./HR. DECAY .00180/SECOND
=NINFL = .56 IN./HR.
~+~* STORM ND. = 1 *~~!* DATE OR RETURN PERIOD = 100-YEAR
TOTAL PRECIF. _ x.01 (1-HOUR RAIN = 2.60) EXECESS PRECIF'. = 1.472
VOLUME OF'-EXCESS F•RECIF' 226. ACRE-FEET
FEAk: Q = 959. CFS TIME OF PEAK = 100. MIN.
INFILT.= 3.00 IN/HR DECAY .00180 FNINF = .50 IN/HR
MAX.PERV.RET.= .SU IN. MAX.IMF'.RET.= .3C~ IN.
*~** STORM N0. _ ~ *~+~* DATE OR RETURN PERIOD = 50-YEAR
'''TAL PFtECIF'. = 2.66 (1-HOUR RAIN = 2.310 EXECESS PRECIF'. =`1.093
VOLUME OF EXCESS F•RECIF' = 16©. ACRE-FEE7
' FEAk; Q = 712. CFS TIME OF PEAk; = 100. MIN.
INFILT.= 3.00 IN/HR DECAY = .06180 FNINF = ,50 IN/HR
MAX.PERV.RET.= .50 IN. MAX.IMF.RET.= .36 IN.
INCHES
~+~++ STOFtM NO. = 3 *+~*+ DATE OR RETURN PERIOD = 10-YEAR
INCHES
~TAL F'RECIP. 1.97 (1-HOUR RAIN = 1.70) EXECESS PRECIF. _ .436 INCHES
VOLUME ^F EXCESS PRECIF' = 67. ACRE-FEET
PEAk: Q 276. CFS TIME OF PEAK = 1G6. MIN.
INFILT.= 3.00 IN/HR DECAY = .00180 FNINF .v6 IN/HR
MAX.F'EF:V.REi.= .50 IN. MAX.IMF'.REi.= .3.0 IN.