Water & Drought

Roseville, Placer to join Sites Reservoir effort. What it means for water storage plan.

Sites Reservoir would be built on 14,000 acres of ranchland in Glenn and Colusa counties. Placer County and the city of Roseville have signed on as investors.
Sites Reservoir would be built on 14,000 acres of ranchland in Glenn and Colusa counties. Placer County and the city of Roseville have signed on as investors. Sacramento Bee file

In a boost for the proposed Sites Reservoir northwest of Sacramento, the city of Roseville and the Placer County Water Agency have agreed to invest in the $4.4 billion project.

The agreements earlier this week show that the Placer agencies, despite having some of the healthiest water supplies in the state, continue to work to augment their portfolios.

The benefit to Placer and Roseville would be indirect. With a proposed capacity of up to 1.8 million acre-feet, Sites would provide another big reservoir that could feed water into the Sacramento-San Joaquin Delta to improve water quality and fish habitat. That would mean Folsom Lake – the primary water source for Placer and Roseville – wouldn’t have to release as much water into the Delta for environmental purposes.

“Folsom Lake often acts as the first responder for environmental issues,” said Maurice Chaney, spokesman for the city of Roseville. “Sites Reservoir can relieve some of the pressure off Folsom.”

So far the financial commitments are fairly small: The two agencies agreed to contribute a combined $140,000 toward planning of Sites, said Ross Branch, spokesman for the Placer water agency. If and when the project breaks ground, which isn’t expected for several years, Roseville and Placer would have to decide whether to move forward with a heftier investment.

Located on 14,000 acres of ranchland straddling Glenn and Colusa counties, Sites would be largely controlled by agricultural districts in the Sacramento Valley. But project backers are asking the state to fund up to half the project’s cost through voter-approved Proposition 1 bond money. If the state agrees to help fund Sites, a portion of the water stored in the reservoir must be dedicated to environmental use. The California Water Commission is expected to decide in 2018 whether Sites will get any Proposition 1 dollars.

Folsom, which is fed by the American River, was drawn down to record low levels in November 2015 to make more water available for endangered winter-run Chinook salmon. That made water agency officials in the region nervous, although municipal drinking supplies were never in danger. Roseville city staff, in a report to the City Council this week, said the existence of Sites in 2015 could have preserved an additional 37,000 acre-feet in Folsom that year.

Sites would get its water from the Sacramento River Basin and could store flows not currently being captured.

Sites backers applauded the involvement of Placer and Roseville.

“We are assembling a critical mass of water agencies who see the vision and need of creating another water supply asset that has lasting statewide benefits,” said Jim Watson, general manager of the Sites Project Joint Powers Authority, in a prepared statement.

Sites would become California’s seventh-largest reservoir. It would be the largest built since New Melones was completed on the Stanislaus River in 1979.

Dale Kasler: 916-321-1066, @dakasler