IMPACTS OF IRRIGATION DEVELOPMENT ON ANADROMOUS FISH IN THE YAKIMA RIVER BASIN, WASHINGTON

Abstract

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.