7316

• UCREFRP Catalog Number: 7316
• Author: U.S. Army Corps of Engineers.
• Title: Redlands Dam Fishway Feasibility Study, Gunnison River, Colorado.
• USFW Year: 1986.
• USFW - Doc Type: Walla Walla.
• Copyright Material: NO

• (b) Bar screen may be installed across all four
power canal headgates. The head loss through the screens is approximately
0.2 foot with all gates fully open. This bar screen will not be installed
until it is determined that the ladder successfully passes fish into the
forebay.
(c) The ladder structure blocks a portion of the
spillway that would normally pass riverflows. Therefore, sediment may
accumulate behind the diversion dam in the ladder area. RWPC may be
asked to open the sluice gates for the purpose of flushing accumulated
sediment from behind the dam.
(d) Construction of the fish ladder will only
have minor impacts on RWPC. The bar screen installation, if necessary,
would be scheduled to coincide with the dewatering of the power canal for
maintenance. Also, the upstream cofferdam can be constructed around the
ladder structure only, and not interfere with the power generation and
irrigation flows in the power canal.
(e) The trash shear boom will reduce the amount
of trash and debris that RWPC must handle at the dam, in the power canal,
and at the powerhouse. However, if the bar screen is added, a greater
portion of the debris will be handled at the dam. Because of this
overall reduction of debris, RWPC will still be responsible for debris
removal.
(2) Impacts Affecting FWS.
(a) FWS will operate and maintain the fishway
facility. This alternate will require-that fish be released from the
trap periodically {check trap every day during migration season), weir
boards be installed or removed, auxiliary flow valves and entrance slide
gates be adjusted, and debris be removed from the fish ladder trashrack.
(b) Also, some maintenance of mechanical equipment
(valves, slide gates, fish hoist) is required intermittently to keep
these items in proper working order.
5. Estimate of Costs.
a. Table 2, Estimate, Alternate No. 1, presents the
materials and installation costs of the fish ladder, bar screen, and
trash shear boom. At the feasibility study level, a contingency factor
of 25 percent is added to the materials and installation costs to account
for the uncertainty of a feasibility level study. An additional 20
• percent has been added to the construction estimate to account for
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