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

Riverine vegetation, including a significant number of trees and shrubs
currently scattered along the stream banks and adJ acent areas, would be lost.
Exceptions would be those trees which could be moved, utilizing tree-moving
equipment, back to the shoreline of the proposed lake.

V. Alternatives to the proposed action.

Solutions considered for alleviating flood problems in the Bear Creek
basin included floodplain zoning and management, floodproofing, channelization,
floodplain evacuation, various dam alignments and corresponding impoundments,
as well as the possibility of "no action".

Floodplain zoning was one of the solutions considered. Implementation
of such zoning, and its management, would be the responsibility of State
or local governments. With this alternative adverse environmental effects
would be nil since zoning would restrict future development in the floodplain,
thus preserving the natural character of the stream and its banks. In fact,
enhancement of the floodplain could result, if capital development were
restricted and the floodplain developed for open space recreation.
However, zoning would offer no flood protection to structures already
located in the floodplain. Insurance could mitigate flood damages suffered
by present residents of the floodplain. However, the threat of loss of life
would remain. As such, zoning is only a partial solution to flood problems
in the basin. This would be the least costly of the alternatives considered
but at the same time would offer the least amount of flood protection to
present basin residents.

Floodproofing was also considered as a solution to the Bear Creek flood
problems. This would involve sealing of basements and the raising of some
buildings; mobile homes, storage sheds and other vulnerable semi-permanent
facilities would have to be removed from the floodplain. Things such as
bridges, utilities, parks and agricultural facilities could not be floodproofed
economically. In plotting floodproofing costs against benefits it was
found that net benefits decreased to zero at a point about midway between
a flood of 1.5 percent severity and one of 1.0 percent severity. (A flood
of 1.0% severity is one that has a 1.0% chance of annual occurrence or one
that would normally be expected to occur no more than once in 100 years.)
Although benefits would increase beyond this point, the benefit-cost ratio
for this alternative would fall below 1.0 to 1. Adverse environmental
effects would concern the physicosocial environment of individuals living
in mobile homes since they would face relocation. Permanent adverse effects
on the biological environment would be minor since the only structural
changes required would be changes to existing buildings. No changes should
result to the undeveloped floodplain.

Floodplain evacuation would involve the removal of nearly 2,000 permanent
homes, some 400 mobile homes, 4 schools, 2 churches, and 24 or more commercial-
type buildings which house numerous large and small businesses. The number
of individuals residing in these structures is currently more than 6,000.
Again environmental effects are primarily physicosocial rather than biological.

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