Friday August 14, 2026
The Economic Times —
One of California’s more unusual salmon conservation efforts involves trucking thousands of tons of gravel to carefully engineered sites along the Sacramento River. The work has continued for decades below Keswick Dam in an effort to restore spawning habitat for endangered winter-run Chinook salmon.
Where the gravel went missing
It all began with Shasta Dam and Keswick Dam, two very large concrete structures that were put up across the Sacramento River in the 1940s and 1950s. These dams provide huge amounts of water and power for California, and the consequence that it had on the fish species that live there, in particular the winter-run Chinook salmon, was a very bad one.
Salmon need much more than water to survive. They need gravel, or, more precisely, loose, clean, and mobile gravel within the riverbed for female Chinook salmon to burrow into and lay their eggs. This nest is called a redd. In the past, when floodwaters rushed downstream, they carried gravel with them and deposited it further down the river, constantly replenishing the shifting gravel beds.