Document Type


Date of Degree Completion

Summer 1995

Degree Name

Master of Science (MS)


Resource Management

Committee Chair

John Ressler

Second Committee Member

Paul W. James

Third Committee Member

George Macinko

Fourth Committee Member

Raymond Z. Riznyk


Prior to Euroamerican development, the Yakima River Basin was a major producer of salmon. Total runs of approximately 800,000 have declined to 3,000-5,000, or less than 1% of original run size. Three species are extinct in the basin, including summer chinook, coho, and sockeye.

Irrigation development, including the construction of unscreened diversions, the blockage of spawning and rearing habitat by reservoir dams, and the dewatering of spawning and rearing habitat, began in the mid-1800's and today totals approximately 500,000 acres. Historical records provide a wealth of information documenting irrigation development and its consequences on anadromous fish populations.