Bay Area water agency may start Sacramento River diversions

A Bay Area water agency may use its water contracts on the Sacramento River for the first time to help its customers survive the ongoing drought.

The East Bay Municipal Utility District anticipates it will need to divert water this year from the Freeport Regional Water Project on the Sacramento River, which it helped build in partnership with Sacramento County at a cost of nearly $1 billion. The district has not used the diversion since it was completed in 2010, but its board will vote in April whether to activate it.

“We’re definitely preparing for the possibility of using Freeport for drought purposes,” said Andrea Pook, a spokeswoman for the district. “It doesn’t mean we will, and we don’t know how much water that will be. Really, there’s a lot that’s still up in the air.”

The district serves about 1.3 million people in Contra Costa and Alameda counties. Normally, their water comes mostly from the Mokelumne River in the Sierra Nevada, diverted across the Sacramento-San Joaquin Delta through a series of reservoirs and pipelines.

The Freeport diversion is a large complex of fish screens, pumps and pipelines in Sacramento, north of the town of Freeport along the Sacramento River. Completion in 2010 marked the end of a decades-long water war in the Sacramento region.

In 1970, EBMUD obtained a contract from the U.S. Bureau of Reclamation to purchase 150,000 acre-feet of water from the American River. Sacramentans feared this would deplete the capital region’s primary recreational asset. Opposition led by the Save the American River Association resulted in a lawsuit and ultimate compromise: EBMUD agreed to shift its water diversion downstream to the Sacramento River, and use it only in drought years.

Sacramento County became a partner in the Freeport diversion because it needed a new water source to meet urban growth demands, and it already is using some of its diversion capacity at Freeport. EBMUD is allowed to use its separate diversion pumps at Freeport only when snowmelt in the Mokelumne River watershed is predicted to fall below 500,000 acre-feet. That is the current prediction, a result of the exceptionally dry winter.

“If it’s under that amount, that means our reservoirs aren’t refilling and we would be eligible to divert from Freeport,” Pook said.

The Freeport intake is connected to EBMUD’s Mokelumne River pipeline through a series of intermediate pipelines. The agency is allowed to divert no more than 133,000 acre-feet of water per year from the Freeport intake, and no more than 165,000 acre-feet in any three consecutive years. However, those numbers are subject to allocation limits set by Reclamation, based on water supply.

On Friday, Reclamation predicted it would be able to meet only 50 percent of municipal needs for its American River contractors, which include EBMUD. That forecast could change if more winter storms arrive.

Related stories from Sacramento Bee