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. The advantages of this ladder include construction on •
land instead of in water. This procedure should greatly reduce construc-
tion costs. Also, a sluice gate would flush sediment past the fish ladder
exit to reduce maintenance. RWPC is currently considering construction
of two additional sluice gates, one located at the midpoint of the
spillway and the other on the right abutment. Therefore, a sluice gate
constructed with a fish ladder may interface with the operational needs
of RWPC.
5. Alternate D, Two Left Bank Ladders with Fish Passage Through
Power Canal and a New Open Channel.
This alternate was selected because of the unique concept
of utilizing existing structures (power canal and headgates) for fish
passage. For this reason, a substantial cost savings may be realized by
choosing this alternate. From the review of biological criteria, the
Denil-type ladder was rejected as a workable fish passage solution and a
baffled flume fishway was selected for further study. The Denil-type
ladder requires fish to swim over baffles, while the flume fishway allows
fish to swim near the floor of the fishway during their ascent. This
condition is more consistent with the swimming preference of the two
target species. Also, the baffled flume fishway has evidence of passing
"weak swimmer" species.
V. STUDY OF FINAL ALTERNATIVES.
A. Background Information.
At the scoping meeting (30-percent feasibility review), four
alternates were selected for further study. During the study period,
preliminary alternate concepts were revised as they were examined more
precisely. A fifth alternate was also suggested for study during the 60-
percent review meeting. This new alternate was proposed to examine poten-
tial cost savings over the original Alternate F. All of these alternates
are described in more detail in the following paragraphs. See Plate 3
for the locations of the five alternates with respect to the existing
Redlands Diversion Dam.
B. Alternate No. 1.
1. Description of Major Features.
a. This alternate closely relates to preliminary Alternate
F described previously. See Plates 4 and 5 for plan and profile views.
This vertical slot/orifice ladder has a downstream entrance located on
the west side of the ladder and a side entrance on the east side of the •
ladder. Each entrance leg leads fish upstream through four ladder pools
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