WSP01249

• File Number: 8220.106
• Description: Animas-La Plata
• State: CO
• Basin: San Juan/Dolores
• Water Division: 7
• Date: 1/1/1990
• Title: Correspondence regarding the Final Biological Opinion - 1991
• Water Supply Pro - Doc Type: Biological Opinion

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ABSTRACT

The San Juan River <lnd tributaries upstream from the Navajo Dam "'ere rotenoned

to eliminate trash fish species wichin the proposed impoundment area. A cotal of

3,870 gallons of rotenone was used for the Navajo, Pine, LInd San Juan Riveu. Lethal

concentrlltions were effective On approximately 70 miles of the San Juan River, 15

miles of the Pine River, and six miles of the ~Llvajo River.

fourteen species of fish. were eliminaced with,this operation, The most abundllnt

species found were the flannelmouth sucker and the bony tail ehub. Channel clltf!Sh

was the predominant game fish in the San Juan IInd Pine Rivers; only four trout were

observed, The game,fish found in the Navajo River were predominantly rainbow trout;

a few brown trout were found.

very good kills were obtained in all three rivers. especially the San Juan,

I~here lothal concentrations of rotenono carried lIpproximll.cely 40 miles belOW the

NlIVlIjo Dam.

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