Barbara Swier: How did salmon survive before there were dams to keep water cold?

We seem to be in danger of losing much of our local rivers’ waters to the ocean for salmon. One would wonder why the state water board, responsibly caring about our water, would even consider sending such a large amount of the Sacramento River through tunnels to bypass the delta when cities and farmers who rely on the Tuolumne, Stanislaus and Merced rivers will suffer unprecedented social and economic harm. And since 97 percent of the salmon in California is provided by the Sacramento River, this isn’t about the salmon. This is about water for southern California.

What I don’t understand is this: Before the dams and reservoirs were built in the Sierras, countless millions of salmon came upstream to spawn. But how?

After the snow had melted in the spring, leaving a flooded valley without controls to the rivers, little by little during the summer the rivers became little streams of warm water. By the fall when almost all the Sierra snow was gone, many were almost nonexistent. Yet, the salmon migrated in the fall by the millions. But now we’re told it takes huge amounts of cold water for salmon to spawn upstream. Huh? Based on history…..

This story was originally published January 27, 2016 at 6:31 PM with the headline "Barbara Swier: How did salmon survive before there were dams to keep water cold?."