The Mokelumne River day use area, where much of the East Bay's water is sourced from. Credit: Benjamin Cossel/BLM

East Bay Municipal Utility District officials declared a “Stage 1” drought on Tuesday, asking residents to cut down their water consumption as the region faces its driest year on record amid statewide drought conditions.

The water district serves most of the East Bay, including Oakland and Berkeley, and officials said during their board meeting Tuesday that rainfall this winter season fell far short of the levels needed to meet storage targets and provide water to its 1.4 million customers.

The Mokelumne River watershed in the Sierra Nevada, which houses the region’s water, has only received about half of its average yearly rainfall overall with no more rain in sight, said Lena Tam, EBMUD manager of water resources planning. Rainfall in the East Bay has been even worse, creating the driest year on record, and rainfall expected last weekend did not materialize.

As a result, the water district is setting a voluntary, region-wide conservation goal of up to 10% to avoid more restrictive, mandatory conservation targets and worse drought conditions during a year when California is also expected to experience a severe fire season. This will be an average goal, so customers are encouraged to conserve even more water to offset those who are only able to conserve less than 10%.

“We have learned from the last drought that our customers have often exceeded our expectations when we ask for a certain level of customer conservation,” Tam said, explaining that customer water usage has remained reasonable even after the region recovered from its last drought in 2014.

EBMUD also decided Tuesday to tap into statewide resources by purchasing water from the Sacramento River at the Freeport Regional Water Facility. This would come in handy if drought conditions become more severe and state water prices spike sharply in the future like they did in 2014. EBMUD can choose to stop purchasing this water if conditions improve and it’s no longer needed.

The Pardee, Camanche, and multiple East Bay reservoirs, which comprise the EBMUD water system, currently have about 534,600 acre-feet of water and are about two-thirds full. Any time that level falls under 500,000 acre-feet, EBMUD requires water conservation locally. The region’s water levels are still in the first stage of drought conditions, but this could worsen to a level where mandatory water conservation is required.

Two water utility companies in Marin County became the first in the Bay Area to institute mandatory water conservation rules last week after Gov. Gavin Newsom declared a drought emergency for the Russian River watershed in Sonoma and Mendocino counties on April 21.

The last time Alameda County was under a state drought emergency was 2014, but the state has not yet declared one locally this year.