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

WIOTl1 AT SO" 23. IiIK. wIDTH...r 75'" 12 IHH. GO" 22 1(75" 30

RAIMFALl LOSSES [NPUT WI BASIN OATA

MAX P[RV[M RH. .. 40 tN. MAX. [JofI[RVlOO$ RfT .10 IN.
INFlLTRATlClt"4.S0IN.lIfl.. DECAY- 00180/SECOO FNINFL" 5OIN.Jtfl.

TrOt: !JUT TIlt: I.OIT TIlt: I.OIT
H'l1lI!OOW'H - H'l1lI!OOW'H
0, 0, 30. 50, 60. 17. .
5. 83. 35. 41. 65, 14,
10. 109. 40. 34 10, 11,
15. 85. 45. 29. 75, 10.
20. 76. so. 24 SO. 8.
25. 61. 55. 20. 85, o.
BASIHlD: 4 .. IlASINCCIt(NT: Sl.B8ASIN[~ 4
*.....*ST(JlH~. .. DATE CR RE'MN PERICD .. lOOYEAA

INCREl!ENT TOT" STCI!M INCREl!ENT TOT.. STCI!M .
TIlt: RAINFAlL EXCESS - TIlt: RAINFAll EXCESS HYIIAOOIW'I! .
(HIN.l (IN) PRECIP (CFS) (HIN,) (IN) PRECIP <as)
.
0, .00 ,000 o. 10. ,115 .007 65. .
5. .03 .000 0, 75, .115 ,007 65.
10, .08 ,001 o. so. .03 .002 46. .
15, .12 0Q8 I. 85 .03 .002 38,
20, .22 .015 2. 90. 03 .002 32.
25. .38 .041 6. 9\, 03 .002 27.
30. .68 .611 57. 100 ,03 .002 23. .
35. .38 .321 99. 1115. .03 002 I.. .
40. .22 164 105. llD. .03 .002 12,
45. 17 .117 1115. 115, ,03 ,002 8, .
50. .1' .086 99. 120. .03 ,002 6. .
55 .11 .060 .. 125. .00 .000 4,
60 .11 .061 81. 130. .00 .000 3,
65 .11 061 75. 135, .00 .000 2, .
TOTAl. PftECIP. - 3.12 (l-H),R RAIN .. 2.70) EXECESSPRECIP, "1.580 lNOt:5
nLKOF EXCESS PRECIP.. 7. ACRE.FEET
PEAK a . lOS.CFS TIf'€ Cf PEN: .. 40. HIN.
INFILT..4.50 IN/~ DECAY".OOI80 FNINF. .60IN/Ifl.
l"A'(,PERV.RET....40IN. 11AX.IMP.RfT....1OIN,
AATlCWAl F/JltU.A C .. 51
I- 3.81HQE.S/fQR
A. 55.7 ACRES
a. :07. CFS
IJ.D.r,C.D CltfPRl.IO"F~YSIS EXEMEDClIOATE ATTlHE

Cl.tlPE/P( '/ERSlON !OlIflEO IN JAtlJARV 1985
?JIUITCfTlCl4t1..MBERSHECTEDFCJl.THISBASIN IS
9LlllVll Gl.lCH: lOO-YR: FEHA FrS: Bf25/97 (BH1ClOF1J.CHIladdH&NiC/pondJ

BASIN!D:

BASIN C()tlfNT' SL6BA$IN [0- 5

MEA r:f BASIH LENGTH OF BASIH OIST T.') CENTROID IMPERVIOJS MfA SLCPE LWIT lX.RATIlJ4
(S(}lll om (Mil (PeT) (FTiFTl (HIN)

04

"

13

40.00

.0200

5.00

CCEFFICIENT COEFFICIENT
(REFLECTING TIME TO PEM) (RELATED TO PEAK RATE OF ~F)

.093 .326

CAlC11.ATEDI.JHTHYDRC!GRAPH

TII'IE TO PEM T/I'IE Of C()f(ENTRATI(W PEAK RATE OF RlJ()FF i.JlIIT HY[)R();RAPH PEAK m.LtIE rF RUICH
(MIN) (MIN) (CFS/S(J111 (CFSl (AE)

9.J]

2400

179462

77.17

2.29

..... ~TE THE TII'IE TO ~ IS CAlCllATED BASED (W THE TIME Of ClXEHTRAT/(W PROVIDED BY nt: USER.
REFUCIHG THE CNE CCJflUTEO BY ctJiPD (Tp.. 7.51>

WIDTH AT ~O. 17. H1N. .IOTH AT 75. 9. MIH. K50..34 K75 - .46

5