FLOOD06896

• County: Larimer
• Community: Larimer County
• Stream Name: Buckhorn Creek, Redstone Creek
• Basin: South Platte
• Title: Buckhorn Creek and Redstone Creek Hydrology Larimer County FIS
• Date: 10/31/1977
• Prepared For: Larimer County
• Prepared By: Gingery Associates, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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A large part of the combined drainage basin is covered by soils
with a high clay content or with solid rock outcrops, and has
bsen glV(D a hydrological c~assification of Group C or Group D,
indicating a high runoff rate. The remaining parts of the basin
are covered with soils which have a lower runoff rate and have
been given a hydrological classification of Group B. Almost 70
percent of the land in the combined basin is classified as wood-
~and, and the remaining 30 percent is classified as cropland,
rangeland, and urban area (References 1 & 2). These soil types
and land uses combine to produce a curve number of 74 as de-

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finsd by ~he Soil Conservation Service (Reference 3).

0')""~ L 'i-"~)"" t:.
\ ;.t-''' 1\ '\fJ ,:. \ /Gvvtc_
// I>I(.J "",...'^~- .
The primary source of flood/producing runoff in the' Buckhorn Creek

and Redstone Creek basln .{s the summer thunders~orm, as indicated Itoood)

by pcevion' flood p~d~ng "'ocm, in JUD' 1941, .nd Annn,' 1951.~ J

The 10- and 100-yea, - our rainfall depths were taken from) ~r 1':t6
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charts in the SOlI Conservation Service "Procedures for Deter-

I)R.l~Cl P ITI\TION

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mining Peak Flows in Colorado" (Reference 3). These depths are
summarized in Table 1.

TABLE 1
BUCKHORN CREEK AND REDSTONE CREEK RAINFALL DATA
(6-Hour)

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10-Year z..::;

~..) 100-Year

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Rainfall (inches)

2.1

3.2

G- \10'-.)'f'
24. h,..J'r

RUNOFF COMPUTl\TIONS

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Discha-ges for the subbasins of Buckhorn and Redstone Creeks
were computed by methods presented in the Colorado Water Conser-
vation Board's "Technical Manual No.1" (Reference 4) to main-
~ain consistency with the Big Thompson River study. The stream