The Long Beach water department has declared that a water shortage is imminent and is urging a half-million residents to conserve.
Officials warn that the port city's supply of imported water could be cut back as early as next year if California's dry spell continues.
Long Beach gets its water from Northern California and the Colorado River.
The water department is barring restaurants from serving drinking water unless requested by customers.
Residents are asked to take shorter showers, and stop overwatering their lawns.