The Ukiah Daily Journal reports that the county's Board of Supervisors on Tuesday voted unanimously to make the declaration, citing an "imminent threat of disaster" from drought conditions.
The state Department of Water Resources said Mendocino is the first to request state drought assistance.
Officials hope the declaration will result in state funds and assistance in developing a drought plan.
Gov. Jerry Brown has convened a task force to help decide if a statewide drought emergency is warranted.
State water managers say they will be able to deliver just 5 percent of the water sought by municipal agencies and nearly a million acres of farmland.
The US Bureau of Reclamation says most farmers south of the Sacramento-San Joaquin Delta will face a second year with no water from the Central Valley Project. Some farmers and cities may receive more.
It would not be an odd sight in the spring. But there is something depressing about a closed ski slope in the middle of winter. The trails are bare and grassy. The chairlifts just hang there, waving a little with the breeze.
A new poll finds nearly all Californians think the state's drought is serious -- and there's growing support for mandatory water rationing.
The California drought has state lawmakers looking for creative and affordable ways to increase the state’s water supply. A legislative hearing Wednesday will highlight ways that could make it easier to capture stormwater.
The California Water Resources Control Board heard emotional testimony for at least 12 hours yesterday from people worried about how the state should manage its dwindling supply of water during the drought.