WSP00945

• File Number: 8442.400
• Description: Missouri Basin - Pick Sloan Project - Reports
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 2/28/1985
• Author: DoI, BoR
• Title: Lake Andes - Wagner Unit Planning Report / draft Enviromental Statement
• Water Supply Pro - Doc Type: Report/Study

installation of subsurface drains and reduce pumping costs. Irrigation
will be by sprinkling, mostly with center pivots.

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A system of surface and subsurface drains will remove excess water and

return flows from the project area. Installation of subsurface drains will

be deferred until they are needed, with anticipated deferral ranging from 5

to 40 years.

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The average annual project diversion of about 92,000 acre-feet would

constitute about V2 percent of the annual releases from Fort Randall Oam

(18,360,000 acre-feet). Return flows will accrue to Lake Andes, an inter-

mittent lake adjacent to the project area, and Choteau Creek, which bisects

the project area.

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The major environmental concern expressed is the loss of wildlife habitat.

The important habitat types in the project area are woodlands (multirow

shelterbelts), wetlands, and grasslands. The project will include measures

to compensate for project-caused damage to wildlife habitat. To mitigate

wetland losses, water will be provided to existing wetland areas near the

project area (Owens Bay area of Lake Andes National Wildlife Refuge and the

Red Lake State Game Production Area), 330 additional acres of wetlands will

be purchased and provided a water supply, and wetland easements will be

acquired for 4 acres. To mitigate woodlands and grasslands, lands will be

purchased, planted, and managed. Canal and lateral rights-of-way will be

seeded to native grasses.

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Other environmental concerns expressed are potential fish losses caused by

pumping from Lake Francis Case and water quality impacts on Choteau Creek

and Lake Andes, which is dry lout of 20 years. The pumping plant has been

designed to minimize fish loss. The Bureau initiated a water quality and

quantity sample program in June 1983. This program will verify any impacts

or benefits to the receiving waters. If study results show a negative

effect, there is ample capacity in the canals to add water to Lake Andes

during off-peak petiQds. Summer water quality in Choteau Creek, an inter-

mittent stream, will probably not be altered. However, water quality con-

ditions during low flow winter months will probably worsen. These

anticipated water quality changes are not expected to impact aquatic life.

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