FLOOD02940

• Designation Number: 291
• County: Grand
• Community: Granby
• Stream Name: Fraser River & Tenmile Creek
• Basin: Colorado Mainstem
• Title: Flood Hazard Identification Report - Fraser River and Tenmile Creek, Granby, Colorado
• Date: 2/1/1987
• Designation Date: 12/1/1987
• Floodplain - Doc Type: Floodplain Report/Masterplan

TABLEL CROSS-SECTION INFQRMATION FOR TENMILE CREEK
Chmme1 lOO-yr lOO-yr l00-yr
X_see bot tOOl flood flood channel
number COll1lllents Locetion'" elev. elev. ..idth velocity
(Station) (ft,msl) (ft,msl) (ft) (ft/see)
10 3+40 7917.3 7920.0 393 '.6
20 7+40 7921.4 7924.5 '" 3.3
30 14+60 7925.0 7927.3 '" 3.9
40 18+20 7928.4 7930.2 '04 3.9
50 21+60 7932.0 7933.3 547 t,.!.
60 32+00 7934.5 7938.0 283 3.9
70 39+20 7941.6 7944.0 987 >.7
80 47+60 7944.5 7947.4 594 3.8
90 53+60 7947.5 7950.8 230 6.2
100 60+40 7950,8 7954,5 215 '.0
110 66+40 7952.4 7956,4 109 3.'
112 6?-20 7953.7 7956.6 52 7.2
115 S'" '0 bridge exit 67+40 7953.7 7957.0 {,J 6.2
m H..y 40 b,.-j~ge t"let 67+60 7953,7 7957.4 46 5.0
120 67+80 7953.0 7957.7 67 3.3
130 69+40 7955.0 7958.2 278 4.2
135 75+60 7958.0 7961.3 110 7.3
140 31+20 7962.4 7966.0 127 6.8
150 86+80 7964.0 7967.9 300 3,0
160 00.80 7966.0 7970.4 6'" 5.1
160 arch 919" outlet 91+00 7966.8 7970.7 296 3.5
166 arch pipe inlet 91+60 7967.8 7971.2 357 1.5 f
166 91+80 7967.9 7971.2 792 1.3
I7C elev. ditch crossing 99+20 7969.0 7971.3 4) U
180 104+80 7971.8 7974.8 135 4.4
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*Dista"c~ ebnvp confluence ..ith old Fraser River c~a~nel.
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P-ECOMMr:NDATIO~S

The findings of the hydrologic ~nd hydraulic investigations can be
used for a n~mbcr of floodplain management activities. These activities
include:

ImplcO\entationof floodplain zoni"g,
Floodproofing structures.
Sizing stream crossings and bridges.
Preparation of a flood control feasibility analysis.
Public a..sreness of flood problems.

By authority vested in Section 30-28-111 of the Colorado Revised
Statutes for cou"ty governments and Section 31-23-201 for f!l\1oic1pal
governments, the cities, to..ns, and counties..ithin the studyarealllBY
enact certain f1ood-related contro1s and regulations '"

"...toestablish, regulate, restrict,andlimitsuchuseson
or along any sror..or flood..aterrunoffchannelor basin",,'such
stOI1llor flood..ater runoff channel or basin has been designated and
approved by the Colorado Water Co"servation Board, in order to
lessen or "void the hazards to persons and damege to property
resultingfromtheacCwtlu1ationofstormorflood"'aters "

Therefore, upon official approval of this report by the Colorado
,,'ater Conserv:.tin" Roaro, the areas described as being innundated by the
lOa-year- flood can be designated as floo~ hazard areaS and their liSe
regulated accordingly by the local agencies. It isreconmended th"t such
regulation be enacted upon such designation.

Follo~ing acceptance of this ~tudy, the TQ~n of Granby may request
to he converted to the Regula! Phase of the National Flood Insurance
Program (NFIP) through the "special conversion provi"ion" of the
program. It is recorntoended that the results of this study be
incorporated into any ne.. Flood Insurance Rate Poaps (FIR~'s) put out by
the Federal Fmergency Management Agency, Federal Insurance Administration
for this area. Specifically, the "Flood ad Ara:l M:lps" ~u this report
could be used to replace the flood haz:lrd boundary liS shown in the
Federal Emergency Jo'",nagement Agency's Flood Hazard Boundary )1..p of August
15, 1975 (see Exhibit 2). Upon Gnmby's convl'rsion to the regul,.,r ph"""
of the :iationa I Flood I"surancc Progra"" additional amounts of Hood
insurance coverage will be available to d..c11ings ..ithin the l00-year
floodplain. Exhibit 3 gives "OOle information on:intional Flood Insurance
Program cov~rag~ ~vail~bl~.

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