FLOOD08945

• County: Larimer
• Community: Fort Collins
• Stream Name: Dry Creek
• Basin: South Platte
• Title: Hydrologic Analysis Major Drainageway Planning Dry Creek
• Date: 7/1/1979
• Prepared For: Larimer County
• Prepared By: Gingery Associates, Inc.
• Floodplain - Doc Type: Floodplain Report/Masterplan

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- THE DRY CREEK BASIN -

Basin Description. The Dry Creek Basin is long and narrow with its
upper reaches in the eastern foothills of the Rocky Mountains and its
lower reaches extending onto the agricultural plains immediately north
of Fort Collins (Figure 1). The basin is in east central Larimer
County with portions of the lower basin extending into Fort Collins.
The basin encompasses a drainage area of approximately 65 square
miles with basin elevations ranging from 7,000 feet MSL in the foot-
hills to 4,900 feel MSL near Fort Collins. The average basin slope
is approximately 2% in a southeasterly direction. Eleven major
irrigation canals and 13 major, and several minor storage reservoirs
are part of an extensive irrigation network within the basin (Figure 2).
The Dry Creek stream channel is tributary to the Cache la Poudre
River immediately east of Fort Collins. The channel generally has a
well defined, meandering low flow section, and a wide, gently sloped
overbank area. In the reach below the Eaton Ditch, however, the
channel has been obliterated by development over much of its length.
The Dry Creek channel has many tributaries along its length with the
major ones, Park Creek and Spring Gulch, joining Dry Creek in the
upper third of the basin.
The channel is intercepted at two locations by major on-stream
reservoirs, Douglas Reservoir and Park Creek Reservoir (Figure 2).
Park Creek Reservoir is a fairly new U.S.B.R. storage reservoir lo-
cated high in the upper basin on the Park Creek tributary to Dry
Creek. The reservoir has a surface area of approximately 190 acres,
and a tributary area of 3.8 square miles. Douglas Reservoir is lo-
cated on Dry Creek in approximately the middle of the basin. This
reservoir has a surface area of about 640 acres and a tributary
drainage area of 44.0 square miles.
Historically, the Dry Creek Basin has been in agricultural land
use with a very active irrigation network. Over the past 30 years,
the basin has been experiencing development in the lower reach below
U.S. Highway 287. The development in some cases has obliterated
the historic Dry Creek channel, particularly in reaches near College
Avenue. Commercial and light industrial development is rapidly ex-
panding in the basin reach near the confluence with the Cache la
poudre River, in the area surrounding the Valley Airpark. The area
immediately downstream of College Avenue is currently experiencing

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