WSP01174

• File Number: 8449.900
• Description: South Platte Projects - Bear Creek
• State: CO
• Basin: South Platte
• Date: 1/1/1968
• Author: USACOE
• Title: Bear Creek Basin, South Platte River and Tributaries, Colorado, Wyoming and Nebraska - Letter from the Secretary of the Army
• Water Supply Pro - Doc Type: Publication

portion of the basin is characterized by rOlling hills. A belt of hogbacks
mark the western boundary of the plains province and divide the basin into
two geologic regions. The major portion of the basin west of the hogbacks
is underlain primarily by pre-Cambrian igneous and metamorphic rocks
including granites, schists and gneisses. The hogbacks are composed of
eastward dipping sedimentary rocks, ranging in age from Carboniferous to
Tertiary, and including sandstones, shales and limestones. The region
east of the hogbacks is underlain by Tertiary and Recent continental
deposits composed of compact sands', silts and clays. The stream channel
is typicallyveneered with Terrace as well as Recent river sand and
gravel deposits,

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STREAM CHARACTERISTICS

,.

Named tributaries of Bear Creek include Vance Creek in the headwaters
area; Cub Creek near Evergreen, Colorado; Mount Vernon Creek at Morrison;
and Turkey Creek and Weaver Creek which join Bear Creek between Morrison
and the mouth. In the mountainous portions of the basin, stream slopes
vary from 500 to 200 feet per mile, whereas in the reach between the
hogback and the mouth the stream slopes average 45 feet per mile. The
stream channel is relatively narrow in the upper basin. From Morrison
to the mouth, channel widths vary from 20 to 200 feet and depthS range
from 4 to 15 feet, Streamflow, fed by mountain snowpack, is perennial,
with periodic rises from accelerated snowmelt and intense rainstorms.
The long-term average daily discharge is approximately 55 cubic feet per
second at Morrison and 35 cubic feet per second at Sheridan. The long
term average annual runoff volume has been 39,600 acre-feet at Morrison
and 24,980 acre-feet at Sheridan. The lesser volume at the lower station
results from streamflow diversions to water supply canals.

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7, ECONOMIC DEVELOPMENT

a. The headwaters areas of the Bear Creek basin are within the ArapehG
National Forest, In general, the portion 'of the basin upstream from
Morrison consists of conifer forest with occasional meadows. Settlements
in the upper basin include Brookvale, Evergreen, Kittridge and Idledale.
Morrison is situated at the hogback and Sheridan is situated near the
mouth of Bear Creek. Generally, the economy of the communities in the
mountain portion of the basin is based primarily on the tourist trade
using U, S, Highway 285 as transients or visitors to the resort areas
in the basin. However, in recent years Evergreen has grown rapi<jly as
a distant "bedroom" suburb of metropolitan Denver. Morrison represents
the western limits of metropolitan Denver. \

b. In the mountain portions of the Bear Creek valley, from Brookvale
to Morrison, economic developments are located principally in the flood
plain, primarily because the narrow valleys provide the only sites suitable
for building, Commercial establishments are concentrated principally at
Evergreen and Morrison, However, fine mountain homes are located adjacent
to the stream throughout the valley from Brookvale to Morrison with greater
ccncentrations of such dwellings near the community centers of Brookvale,
Idledale, Evergreen and Morrison. Highway systems and public utilities

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