WSP01569

• File Number: 8449.900
• Description: Bear Creek
• State: CO
• Basin: South Platte
• Date: 2/4/1972
• Author: USACOE
• Title: Final Environmental Statement for Bear Creek Flood Control Project
• Water Supply Pro - Doc Type: EIS

The only adverse biological effects would be the presence of a "torn up"
,floodplain after evacuation was completed. This would only be temporary, however,
since the area would be filled, levelled, seeded and planted after the
buildings were removed. Costs involved with this alternative would
amount to many millions of dollars due to the extent of present development.

Chanoelizatioo was another alternative that was considered, This
alternative was considered for both upstream and downstream reaches of
Bear Creek and benefits were assessed to each of these. For the upstream
reach channelization would not be a realistic solution to the problem since
the majority of flood damages occur downstream. Compared to upstream
channelization, downstream channelization would be a better solution to
the problem. However, since Turkey and Mt. Vernon Creeks also feed
water into Bear Creek, these tributaries would also need channel modifications
if the system were to have meaning. The costs of several miles of channelization
would be high and the level of fiood protection would not be as great
as that provided by a fiood control dam. Adverse environmental effects
associated with channelization are the elimination of fish habitat,
destruction of wildlife habitat on streambanks, degradation of water quality
through increased erosion and siltation, increases ,in water temperature
because of removal of streamsid" vegetation, a greater flood threat to
unchannelized areas further downstream than presently exists, plus a loss
of streamside aesthetic values. These effects, which would decrease the
populations of fish and wildlife, outweigh the limited increase in flood
protection.

Also considered was the alternative of "no action". This would offer
no solution to the present flood threat. As mentioned above there are
nearly 2,000 permanent homes and over 400 mobile homes in the floodplain
area which could suffer damage from flooding. This development represents
over 6,000 individuals. Urbanization is expected to increase rapidly
in the next 10-30 years with the eventual development of all of the
valley below Morrison. Future development ie expected to be of the same
type that exists in the basin now. Population in the Bear Creek basin area
subject to flOOding should reach 10,000 individuals by the year 2000.
Based on increases in population and real estate values, the value of
future damage could easily be 2 to 3 times the present value. The ecological
impact of this alternative would be that the floodplain below Morrison
would be entirely developed by the year 2000 without the passage of local
zoning ordinances to restrict it. Urban sprawl would eventually cover the
reservoir area and project lands.

The only other alternative considered for flood control in Bear Creek
basin was a dam and lake project. Several sites were proposed for a dam.
If a dam were built upstream from Morrison, it would control only a small
portion of the drainage basin and it would require an embankment over 300
feet in height. Also needed would be supplementary embankments on Mt. Vernon

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