Forced by drought to take dramatic action, California officials are poised to curtail rights to draw water from the Russian River above Healdsburg for the first time anyone can recall.

"It's unprecedented," said Janet Pauli, a Mendocino County rancher who sits on the boards of multiple water organizations.

The state Water Resources Control Board could begin ordering people with junior appropriative water rights — generally those issued by the state after 1914 — to stop drawing water from the river as early as Monday, officials said. The date initially was April 15, but the board postponed making a decision on the Russian River. It did move forward, however, on creating new regulations to curtail water use on three Sacramento River tributaries and the Scott River in Siskiyou County to ensure there is sufficient water in those streams to protect salmon and steelhead.

Should the water board move ahead with curtailments in Sonoma and Mendocino counties, the people with the newest appropriative rights would be among the first to face cutbacks. But the upper Russian River has a complex web of rights, and it won't be as simple as giving the highest priority to the people with the most senior rights, local and state water officials say.

"The Russian is unique," said state water board spokesman Tim Moran. It has multiple reservoirs and a diversion from the Eel River, which created relatively new water sources, local and state officials note. Those new water sources cannot be utilized by the holders of older rights unless they also have contracts or permits to use the new water.

Most farmers and water agencies along the upper Russian River in Mendocino County have a variety of water sources ranging from riparian — those derived from natural flows on a property — to contracts for so-called "project" water that is stored in Lake Mendocino, said Sean White, director of the Russian River Flood Control and Water Conservation Improvement District. They also may have state-permitted rights, groundwater wells and individual reservoirs.

While older water rights by law generally are superior, they don't guarantee water. Some rights to upper Russian River flows — including senior riparian rights — dwindle most summers and could disappear altogether in very dry years, like the current one. The state also is considering restricting those rights in June, but it won't have an effect on most farmers, White said.

"They all know there's no riparian water" in summers like this, he said.

State water officials have said the curtailments aren't expected to affect water already captured in reservoirs but could prevent more from being collected. The rights to Lake Mendocino water are held by the Sonoma County Water Agency and the Russian River Flood Control and Water Conservation Improvement District.

Moran said Friday that officials are monitoring river flows daily to determine whether curtailments in the Russian River and other high-priority rivers are necessary. He said he does not know how many upper Russian River water rights holders would be affected.

Farmers and water agencies that depend on the upper Russian River hope to avoid state intervention by working on water-saving plans of their own.

"A bunch of us are working behind the scenes to coordinate what's going to happen," said Mendocino County Farm Bureau director Devon Jones.

Their plans include coordinating water withdrawals from the river so there are no sudden declines in river flows, said Sonoma County Water Agency Principal Engineer Don Seymour.

The agency is required to release extra water from Lake Mendocino when demand spikes in order to avoid river levels dropping below specified levels, he said. State officials said they will determine those levels as they order curtailments.

One way that could even the flows and conserve water in the reservoir would be to have farmers on one side of the river irrigate on even days and farmers on the other side irrigate on odd days, Seymour said.

"Hopefully that would spread the demand a little bit and reduce the variability" of the river flows, he said.

While the threat of water rights curtailments by the state would be new, it's not surprising given we're in a record-breaking drought, Pauli said.

"Regardless of the state board, we have a real problem. We have a serious problem," she said.

Many water agencies and cities dependent on the Russian River already have instituted water cutbacks and more will be needed, Pauli said.

"Everybody, everybody should be conserving," she said.

(You can reach Staff Writer Glenda Anderson at 462-6473 or glenda.anderson@pressdemocrat.com.)