FLOOD05212

• County: Larimer
• Community: Fort Collins
• Stream Name: Boxelder Creek, Spring Creek, Dry Creek
• Basin: South Platte
• Title: Flood Control for Boxelder Creek at Fort Collins
• Date: 2/1/1993
• Prepared For: Fort Collins
• Prepared By: US Army Corps of Engineers
• Floodplain - Doc Type: Floodplain Report/Masterplan

BOXELDER CREEK
Bo:t.elder Creek is.a left-bank tributary of the Cache La Poudre River. It flows
from north to south beginning at its headwaters in southern Wyoming at an elevation
of 7720 feet m.s.!. and ending at its confluence with the Cache La Poudre River at
an elevation of 4860 feet m.s.!. The Boxelder Creek drainage basin covers an area
of 25 I square miles in Albany and Laramie Counties, Wyoming, and Larimer and
Weld Counties, Colorado. The basin is about 32 miles long and 8 miles wide.
Boxelder Creek flows along the northea'lt edge of Fort Collins and joins the Cache
La Poudre River south of Drake Road. Boxelder Creek has four tributaries. They
are Sand Creek, Rawhide Creek, Indian Creek, and Cooper Slough (see figure 2-1).
Approximately 176 square miles of the basin are controlled by Soil Conservation
Service flood control dams B-2, B-4, B-5,and B-6near Wellington, Colorado, which
is about 8 miles upstream from Fort Collins.

The Boxelder Creek basin lies within the Colorad0-Piedm0nt se-:tion of the Great
Plains. The northern portion of the basin consists of rolling plaleaus, below which
is an area of hogback ridgcsand narrow mesas interspersed v.ith narrow vallcysand
canyons. Easl and south of these ridges and mesas is an area of rnlling plains which
extends south to the Cache La Poudre River flood plain. Most of the land use in the
basin is agricultural except for some commercial land use in the Fort Collins area.

SPRING C(l:F.F'K
Spring Creek, which is a righI-bank tributary of the Cache La Poudre River, flows
from \\!Cst to ea'lt through Fort Collins. Beginning at Spring Canyon Dam and
Horsetooth Reservoir, Spring Creek f1owSea'lterly until !tjoins the Cache La Poudre
River northeast of the intersection of Timberline Road and Prospect Road. The
Spring Creek basin has a drainage area of 30 square miles. The upper 18 square
miles of the basin is controlled by Spring a'ld Dixon Canyon Dams and Horse!ooth

2-4

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Reservoir, which were constructed by the Bureau of Reclamation in 1954. Below the
dam, the Spring Creek drainage basin's 12 square miles of uncontrolled area has a
mean basin elevation of about 5050 feet m.s.!. Downstream from HorselOOth
Reservoir, Spring Cn:ek has an average slope of about 52 feet per mile.

The Spring Creek basin is almost fully developed from Taft Hill Road to its
confluence with the Cache La Poudre River. Upstream from Taft Hill Road, the
basin is currently being developed as a residential area. Development downstream
from Taft Hill Road is primarily residential except along College Avenue, where
there is heavy commercial development. There is some light industrial development
near Spring Creek's confluence with the Cache La Poudre River.

CLIMATE

The climate in Fort Collins is typical of the eastern foothills of the Rocky
Mountains. The mean annual temperature is 48.5 degrees Fahrenheit (F). July,
which is the warmest month, averages 71.4 degrees F., and January, whieh is the
coldest month, averages 26.9 degrees F. The average annual precipitation in Fort
Collins is 12.4 inches, as reported in the 1989 National Oceanic and Atmospheric
Administrations's Climatological Data Annual Summary for Colorado.

Ei"-iviRo;...1ViEi\jAL SEITiNG

Fort Collins is located in the Dry Domain =region and Great Plains-Shortgtass
Prairie province of the United Slates. Much of Dry Cn:ek is an urban riparian
o::osystem or an agricultural riparian o::osystem. The stream has not been assigned
any valued fishery resource classification. The following paragraphs provide a brief
.1cs.:rlption of :;.;:vcra: rca.:.:-"cs uf Diy Ct.:",...

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