Affected areas include parts of Los Angeles, Ventura and San Bernardino counties, home to around six million people
Officials made the announcement on Tuesday that, from 1st June, outdoor watering would be restricted to one day a week in areas dependent on a network of aqueducts known as the State Water Project.
The Metropolitan Water District of Southern California (MWD) has also asked residents to voluntarily cut water use across the region.
“We’re requiring these areas to cut back outdoor watering to 1 day a week, but need all #SoCal residents + businesses to save up to 30%,” the water services company tweeted.
“Due to the depth and duration of the current drought,” MWD wrote, the agency “cannot meet normal demands” in areas that depend on water from the State Water Project.
Some small exceptions are allowed such as for high-efficiency irrigation systems like drip irrigation — where water slowly drips from a porous hose instead of flowing out of a spigot — and hand-watering which is necessary to the long-term health of trees and plants.
With watering of lawns cut back to one day a week, the Los Angeles Department of Water and Power (LADWP) is offering a rebate program for residents and commercial property owners to replace turf lawns with water retention features and drought-resistant plants more suited to the semi-arid climate.
California has been in a sustained drought for the past three years, ravaging the state’s water supply system. Over 95 per cent of the state is currently in “severe drought” conditions, according to the federal government’s drought monitor.
In the emergency declaration, MWD referenced the role of the climate crisis in driving water uncertainty.
“In addition to reduced precipitation since 2020, California’s climate is transitioning to a warmer setting in which historical relationships among temperature, precipitation, and runoff are changing,” MWD wrote.
Much of California’s water comes from snowpack in the Sierra Nevada mountains. Earlier this month, LADWP warned that snowpack was less than a quarter of normal levels, and called on Californians to voluntarily cut water use.
The California Department of Water Resources has warned that the snowpack in the Sierra is expected to decline by up to 65 per cent by the end of the century.
In addition, a 2015 study found that the climate crisis will likely increase the probability that dry years coincide with warm years in California — fuelling the perfect conditions for serious drought conditions.