Salmon and other anadromous fish are picky when it comes to reproduction. They need just the right combination of water depth, temperature, current and river bottom conditions. On the American River, just below the Nimbus Dam, the Bureau of Reclamation are giving them some help.
Using rock sorters and earth movers, loads of small pebbles are dumped into the river and then smoothed into ridges. Salmon make their nests - or 'reds'- in shallow pebbly areas off the main channel. The river is so low that the construction crews can easily stage equipment and sort rocks on the banks. The work will continue until the end of August, with tree planting to follow. Learn more by reading the Bureau of Reclamation press release.