FLOOD02246

• County: Boulder
• Community: Boulder
• Stream Name: Bullhead Gulch
• Basin: South Platte
• Title: Bullhead Gulch Hydrology Report
• Date: 8/22/1997
• Prepared For: FEMA
• Prepared By: Taggart Engineering Associates, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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August 25,1997 BHIOOFI3.CHO

AREA <Y BAStN LENGTH ~ BASIN om TO CENTROID IMPERVIQJS MEA $lCI'E t'UT lUATJ(It
(Sf."1) (HIl (HI) (PCT) CFT/FTl (HIN)

!7

64

19

2.00

.0170

5.00

CClFFrCIENT COEFFICIENT
(REFLECTING TIME TO PEAK) (RELATED TO PfAK RATE ry RL.N:f"Fl

.156

265

CAlCllATEO LNIT HYMWW'H
T11'€ TO Pf:AA PEN: RATE OF RtJrICfF LNIT HYMOllAP PfM VQ..lI1E IF RlJG'F
(HIN) CCFS/S()I1l eCFS> (I<i)

11.53

1084.74

180.07

8.85

WIDTH AT 50" 2B. MIN. WIDTH AT 75" 14. HIN. !GO 0& .25 '05..34

RAINfAlL lOSSES IHPUT WI BASIN OATA

tw. PfRVH1JS RET. .. .40 IN. ""-X. l/ftRVICUS RfT. .10 IN.
IHF!LTRATlClI" 4,50 IN.II''ft. DECAY" .ODl80/SECCNl FNIHFl".60 IN./t<<.

TlHE !.NIT TlHE !.NIT TlHE !.NIT
IfYfIlllQWH HYlJ!ll;lW'It IfYfIlllQWH .
.
o. 0, 40. 69, . 80. 18,
5, 100. 45, 59. as, 15.
10. 176. 68. 68, 90. 13.
15. 167. 65. 42. 95, 11,
20. 137. 50, 35. 100. 9.
25. 119, 65, 30. IOS. 8.
30. 99. 70. 25. . 110. 0,
35, 82, 75, 21. O. o.
BASIHID: " .. BASIN (()tENT: SlIlBASlN ID-o 57

-STCRlNl). ..

DATE M RE'TtlW PfRlOO .. lDOYEN!;

IHCREHE!<T TOTAl. ST"'" IHCREHENT TOTAl. STlBI .
TlHE RAINF.fLL EXCESS IfYfIlllQWH . TlHE RAINFAlL EXCESS - .
(MIN.) (IN) PRECIP (CFS) UtlH.) IIN) PRECIP ICFSl
.
o. .00 .000 o. 80. .03 .001 89. .
5. 03 .000 o. 85. 03 .001 70.
10. .08 .000 o. 90. .03 .001 64. .
15 .12 .002 o. 95. .03 .001 54,
20. .22 .004 1. 100. .03 001 46.
25. .38 .023 3. 105. ,03 .001 39. .
30. .68 .609 66. no. .03 .001 33.
35. .38 .319 144. 115. ,03 .001 18. .
40 .22 .161 178. 120. .03 ,001 24. .
45 .17 .lIS 180. 125. .00 000 20.
50. .14 .084 175, 130. 00 .000 17.
65. .11 .058 163. 135. .00 .000 10.
60. .11 .058 149, 140. .00 .000 7. .
65. .11 .059 137. 145. .00 .000 4. .
70. 05 .005 122. 150. .00 .000 3.
75. .05 .005 105 165 .00 .000 2.
TOTAlPRECIP." 3.1Z(Uo..Jl;RAIN.. 2.7Q} [X[CESSPRECIP, -1.508 INCHES
VQLI'lE!JEXCESSPRfClp.. 13. ACRf-FEET
PEAK Q .. 180. CFS TIf'IE OF PEAK- 45. MIN.
iNflLT,-4.50 IN/~ OECAY..OO180 FNIHf- .50 IN/~
MAX.PERV,RH.-.40 rH. HAX.IMP.RET.- .10 IH.
U.D.F.C.O. C!.H'RlJ()fFAfW.YSIS EXECuTEO c:w OATE AT TIME
CUiPE/PC VERSIC>>tl1XllFTEO IN JAMJARV 1985
PRIHTOPT1~M..teERSElECTED F(]l: THfS ~{N IS
BllU{AD IllCH: lOO-YR: FEMA FrS: 8/25/97 (8HlOOFIJ.CHIladdH&.4bC/pond3
BASIN[D- 58 BAS!NC()fIfNT SLEl8ASIH 10- 58
AREA Of BASIN LENGTH ry: BASIN om TO CEMmow IMPERVlctIS AREA Sl.~ lJUT ll.RATlCll
(5()1IJ (1m (Mf) (PO) (FT/FTl (PUN)

15

.73

5.00

.43

40.00

.0310

COEFFICIENT m:FFICIENT
(REFlECTING TlI'IE TO ?EAt) (RELATED TO PEAl RAn: OF RLN:;fF)

093

.394

48