Some 5,700 farmers from Fresno north to the Oregon border have been jolted by a ruling from the California State Water Resources Control Board (SWRCB) that orders them to cease diverting water from nearby reservoirs.

The SWRCB took the action Aug. 4, on the second day of a two-day meeting in Sacramento.

Although farmers in some parts of the state will be impacted, the ban won’t affect the Tri-Valley because its water supplies, which come from Lake Oroville and San Luis, are already secured via pre-1914 appropriative water rights, according to Zone 7 general manager Valerie Pryor. Appropriative water rights apply to someone who takes water for use on non-riparian land or who uses water that would not be there under natural conditions on riparian land. Water right permits and licenses issued by the SWRCB and its predecessors are appropriative water rights.

Lake Oroville is 120 miles north of Livermore and the San Luis Reservoir near Hollister, about 80 miles south of Livermore.

However, according to a regional board staff member, water levels in those two reservoirs are down. At Lake Oroville, the level is at a record low and threatens to go from the current 645-foot level to below the 640-foot depth at the dam wall. If it reaches that mark, it could reduce power generation from the dam. As of Aug. 2, Oroville was at 24% capacity. San Luis’ level is lower than normal, at 42% of the historic mark for this time of the year.

While Zone 7 is in good shape on its supply of water in the Tri-Valley’s underground basin and is projecting adequacy over the next few years, the region still needs agreements with other water agencies to hold up that side of the water supply, said Pryor.

The challenge for Zone 7, with predictions for more drought conditions next year, will be to see what kind of deals it can make with other agencies to acquire water.

Zone 7 will negotiate alongside the Valley’s water retailers, but with many agencies looking for water, there will be competition on price, said Pryor.

The decisions about potential sellers to Zone 7 will be made in closed sessions, as permitted under the Brown Act, because tipping off others could bring more competition for the water and drive up the price. The deal will go public when staff has a recommendation for action from the board.