9522

• UCREFRP Catalog Number: 9522
• Author: U.S. Fish and Wildlife Service.
• Title: Life History of the Colorado Squawfish in the vicinity of Tusher Rapid.
• USFW Year: 1984.
• USFW - Doc Type: Vernal.
• Copyright Material: NO

Proposed Development at Tusher Rapid
Information on the proposed Thayn Hydroelectric Project was obtained from
the FERC Application for exemption of small Hydroelectric power project from
licensing, Thayn Hydroelectric Project, March 1983.
. The proposed hydropower facility at Tusher Rapid would have the capability
to divert approximately 4000 cfs from the Green River into a canal and through
a powerhouse containing hydro-turbines. The balance of flow would pass over
the diversion weir.
The portion of normal discharge which would be diverted into the turbines
is shown graphically in Figures 10 and 11. Figure 10 shows that a]1 the flow
from the Green River for the years 1979-83 would be diverted into the turbines
an average of 52% of the time and that half of the flow would be diverted 78%
of the time. For example, in 1980 when flow conditions appeared conducive to
Colorado squawfish.reproductive success the entire river could have been
diverted up to 64% of the time. .Figure 11 depicts total river discharge
relative to the 4000 cfs which would be diverted by the project for the period
March - December of 1980. During the critical Colorado squawfish nursery
period of August - November, the entire river would be diverted except for a
few peaks that may or may not occur, depending on the water year.