Changes to Shasta water release designed to protect salmon RIO VISTA — The U.S. Bureau of Reclamation on Sunday will begin releasing warmer water from the upper layers of the Shasta Reservoir directly into the Sacramento River to maintain flows, while saving colder water for the winter-run Chinook salmon migration. “The only remaining population of winter-run Chinook salmon in the Central Valley is in the Sacramento River downstream of Shasta Dam,” David Mooney, Reclamation’s Bay-Delta office manager, said in a statement released Friday. “Last year, despite dry conditions, we effectively shaped cold water for higher survival rates, but other factors reduced survival to very low levels. Protecting egg incubation in this second year will help support this endangered species for the future.”