California governor Jerry Brown has ordered state officials to impose mandatory water restrictions for the first time in history as the state grapples with a serious drought.
In an executive order issued today, Mr Brown ordered the state water board to implement reductions in cities and towns to cut usage by 25%.
The move will impact residents, businesses, farmers and other users.
Mr Brown said the historic drought demands unprecedented action.
The order will also require campuses, golf courses, cemeteries and other large landscapes to significantly cut water use and ban watering of grass on public street medians.
Mr Brown made the announcement as state officials conducted the winter's final manual survey of the snowpack in the Sierra Nevada.
He was speaking at a news conference in the Sierra Nevada, where dry, brown grass surrounded a site that would normally be snow-covered at this time of year.
"We have to pull together and save water in every way we can," Mr Brown said.
The snowpack has been in decline all year, with electronic measurements in March showing the statewide snow water equivalent at 19% of the historical average for that date.
Officials say the snowpack is already far below the historic lows of 1977 and 2014, when it was 25% of normal on April 1 - the time when the snowpack is generally at its peak.
Mr Brown declared a drought emergency and stressed the need for sustained water conservation.