Central Valley of California
Location: The Sacramento originates in the southern Cascade Range of northern California and the San Joaquin drains the Sierra Nevada mountains of southern California. Together they collect approximately 40% of the freshwater of the state. These two rivers meet in the “delta” before flowing into the lower San Francisco Bay Estuary and out the Golden Gate into the Pacific Ocean.
Types of salmon supported historically: These rivers supported at least four distinct runs (and dozens of populations) of Chinook salmon – a greater diversity for this species than any other river system in the world. Steelhead also live in the Sacramento and San Joaquin and their many tributaries. Coho salmon once spawned here as well.
Estimated numbers of salmon historically: Even immediately after the construction of major dams on the Sacramento (Shasta) and San Joaquin (Friant), the number of Chinook salmon spawning in the Central Valley probably exceeded 1,000,000 individuals per year. Naturally spawning steelhead numbers were as high as 12,000.
Current status: Two runs of Central Valley Chinook salmon are protected under the federal and state Endangered Species Acts – counts of the endangered “winter run” Chinook salmon regularly exceeded 100,000 spawners in the late 1960’s but have averaged less than 10,000 fish over the past 25 years. Steelhead are listed as a threatened species, their numbers having declined from over 15,000 spawners per year to approximately 1,000 spawners currently. The economically important Sacramento River Chinook salmon fall run declined more than 90% since the middle of this decade.
Major threat to salmon in this river: Giant water diversion pumps, owned by the federal and state governments, export vast quantities of freshwater from the Delta to inefficient agribusiness operations in the Central Valley. This pumping kills outmigrating juvenile salmon and steelhead (“smolts”) and alters the habitat for those that are not entrained by the pumps. Pumping has increased dramatically in recent years. Also, water storage in upstream dams makes some rivers, like the San Joaquin, go completely dry during some months and produces temperatures in other rivers (e.g. the Sacramento River) that are too high for incubating salmon eggs and rearing juveniles.
Needed Actions: Water pumping in the Delta must be cut back significantly. A large percentage of the annual salmon production is simply sucked into the pumps along with lots of potential salmon food items. Water releases from behind dams must occur throughout the year to keep rivers running and maintain salmon habitats. Agencies responsible for the water pumping are the US Bureau of Reclamation and the California Department of Water Resources.
The San Joaquin ‘River’ does not flow to the ocean because of dams and other water diversions. Picture courtesy of The Bay Institute.
To learn more: Visit the website of the Institute for Fisheries Resources, the Center for Biological Diversity, The Bay Institute, and the Pacific Coast Federation of Fisherman’s Associations, some of SalmonAID’s member organizations. PCFFA is a coalition of commercial fishing organizations that are composed of independent business people who rent or own their individual fishing boats. Find out why these small business owners have rallied behind protecting and restoring our endangered Pacific salmon species.