Trinity Journal: Shasta target level could impact Trinity

Article by Amy Gittelsohn

December 23, 2015

Shasta target level could impact Trinity

By AMY GITTELSOHN The Trinity Journal | Posted: Wednesday, December 23, 2015 6:15 am

State officials have softened a proposed order that Lake Shasta hold a minimum of 1.6 million acre-feet of water at the end of October 2016 to protect endangered winter-run chinook salmon.

The order could still impact Trinity Lake, which is operated in conjunction with Shasta and has no minimum storage restrictions.

The order the State Water Resources Control Board issued Dec. 15 calls for the 1.6 million acre-feet as a target storage level, or that another target be met that will ensure temperature requirements are met to protect the winter-run chinook.

“That’s a target for them to shoot for, but they’ve got some flexibility,” said Tim Moran, spokesman for the state water board. “The goal is to get the temperature where it should be, and if they can do it some other way, that’s OK.”

Because water from the Trinity reservoir is diverted via tunnels to the Sacramento River for Central Valley Project purposes, there is the potential that Trinity Lake will be tapped to make up the difference if more water is retained in Shasta.

From the federal Bureau of Reclamation’s Northern California Area Office, Deputy Area Manager Don Bader said typically if the agency needed to keep Shasta full Reclamation would draw from Trinity, “which we did last year.”

“Bottom line is if they do require Shasta be kept fuller during the summer months it’s going to be more of a draw on Trinity, if it’s available,” he said.

However, he noted that the Trinity reservoir is still very low even with the recent rains.

In addition to the target of 1.6 million acre-feet in the Shasta reservoir, a target level of 200,000 acre-feet at the end of October is called for in the Folsom reservoir. By comparison, Shasta reservoir was at 1.4 million acre-feet at the end of October this year, and Folsom was at 148,200 acre-feet.

The Bureau of Reclamation and state Department of Water Resources have until March 15 to complete a Sacramento River Temperature Management Plan, at which point there will be more information on snowpack and precipitation.

From the state board, Moran noted the order requires that the temperature plan not result in redirected impacts to other salmonid species in the Sacramento or Trinity River basins.

According to the state Department of Fish and Wildlife, winter-run chinook salmon spawn almost entirely in the Sacramento River and its tributaries upstream of Red Bluff, arriving there as early as December, with spawning occurring from April through August.

The state board raised concerns regarding extinction of the winter-run chinook, which has a three-year life cycle.

The state board noted that winter-run chinook eggs and young salmon experienced almost total mortality in 2014 in the Sacramento River, which was too warm to support them. Despite efforts to protect them in 2015, the run appears to have experienced even higher mortality rates in 2015, state officials said.

Water released to the Sacramento River is not supposed to exceed 56 degrees for the eggs and hatchlings, but without enough cold water behind Shasta Dam that limit was exceeded.