WSP06410

• File Number: 8282.600.20
• Description: Colorado River Interim Surplus
• Basin: Colorado Mainstem
• Date: 1/1/2001
• Author: USDOI/BOR
• Title: Colorado River Interim Surplus Criteria Final EIS Record of Decision
• Water Supply Pro - Doc Type: Record of Decision

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3.

Aquatic Resources

Reclamation will initiate a temperature IlDnitoring program below Hoover Dam with statc
and other Federal agencies to document temperature changes related to baseline
conditions am impementalion of interim surplus guidelines am assess their potential
effects on listed species and the sport fishery. The existing hydro lab below Hoover Dam
will be modified as necessary to provide this temperature data.

4. Special Status Species

Reclamation will implement the following conservation measures for Razorback sucker in
Lake Mead and native fISh in Lakc Mohave:

1.

Reclamation wiD continue to provide funding am support for the ongoing Lake
Mead Razorback Sucker study. The lOcus wiD be on locating populations of
razorbacks in Lake Mead from the lower Grand Canyon (Separalion Canyon) area
downstream to Hoover Dam, documenting use and availability of spawning areas
at various water elevalions, c1aritying substrate requirements, monitoring potential
nursery areas, comiIllling ageing studies and confimling recruitment events that
may be tied to physical conditions in the lake. The expanded program will be
devebped within 9 months of signing the BO and implemented by January 2002.
Initial studies will extend for 5 years, foDowed by a review and determination of
the scope of studies for the remaining 10 years of the Interim Surplus Guidelines
(ISG). Reclamation will use the bathymetric surveys, to be conducted in fIScal
year 2001, to gather data in the areas of the identified spawning habitat, ifnot
already available;

2.

Reclanlation will to the maximum exlent practicable provide rising spring
(February through April) watcr Sllrfuce elevations of5-1 0 feet on lake Mead, to
the extent hydrologic conditions aDow. Hydrologic studies imicate that such
conditions could occur once in 6 years, although no guarantee of frequency can be
made. This operatvn plan wiD be pursued through BHBFs and/or equalization
and achieved thro ugh the Adapt ive Management Pro gram and Annu al Opera ting
Plan processes, as needed for spawning razorback suckers;

3.

Reclamation will conlinue existing operations in Lake Mohave that benefit native
fish during the 15-yeareffective period of these Guidelines am wiD explore
additional ways to provide benefils to native fish; and,

4.

Reclamation will monitor water levels of Lake Mead from February through April
of each yeardwing Ihe 15 years these Guidelines are in place. Should water levels
reach 1160 feet because of the irrqJlcmentation of these Guidelines, Reclatmtion
will implement a program to collect and rear larval razorbacks in Lake Mead the

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