A HISTORY OF THE SALMONID DECLINE IN THE RUSSIAN RIVER A Cooperative Project Sponsored by Sonoma County Water Agency California State Coastal Conservancy Steiner Environmental Consulting Prepared by Steiner Environmental Consulting August 1996 Steiner Environmental Consulting Fisheries, Wildlife, and Environmental Quality P. O. Box 250 Potter Valley, CA 95469 A HISTORY OF THE SALMONID DECLINE IN THE RUSSIAN RIVER A Cooperative Project Sponsored By Sonoma County Water Agency California State Coastal Conservancy Steiner Environmental Consulting Prepared by Steiner Environmental Consulting P.O. Box 250 Potter Valley, CA 95469 August 1996 (707) 743-1815 (707) 743-1816 f«x
[email protected] EXECUTIVE SUMMARY BACKGROUND Introduction This report gathers together the best available information to provide the historical and current status of chinook salmon, coho salmon, pink salmon, and steelhead in the Russian River basin. Although the historical records are limited, all sources depict a river system where the once dominant salmonids have declined dramatically. The last 150 years of human activities have transformed the Russian River basin into a watershed heavily altered by agriculture and urban development. Flows in the main river channel river are heavily regulated. The result is a river system with significantly compromised biological functions. The anthropogenic factors contributing to the decline of salmonids are discussed. Study Area The 1,485 square mile Russian River watershed, roughly 80 miles long and 10 to 30 miles wide, lies in Mendocino, Sonoma, and Lake counties. The basin topography is characterized by a sequence of northwest/southeast trending fault-block ridges and alluvial valleys. Lying within a region of Mediterranean climate, the watershed is divided into a fog-influenced coastal region and an interior region of hot, dry summers.