Starting next week, about 1 million residents and business owners in the eastern San Gabriel Valley and the western Inland Empire will be asked to stop all landscape watering and cut back on indoor water use for a week while a regional water agency repairs a major water pipeline.
The Metropolitan Water District of Southern California is making the unusual request to ensure that several local water agencies that rely on the MWD for supplemental water can continue to meet the high summer demands after the district shuts down a 26-mile feeder line.
"This is a major pipeline," said MWD spokesman Adan Ortega. "You can walk inside this pipeline."
For seven days, starting Monday, the MWD wants residents and merchants in La Verne, Claremont, Chino, Chino Hills, Montclair, Ontario, Rancho Cucamonga, Upland and Fontana to dramatically reduce water use.
During that period the MWD wants residents to stop watering their lawns and plants, hand-washing cars, filling swimming pools and hosing down driveways and sidewalks.
The district is also urging people to take shorter showers, run only full loads of laundry and shut off water while brushing their teeth.
Meteorologists predict continued warm weather next week, with temperatures in Ontario and surrounding areas reaching the mid-80s on Monday and Tuesday.
To help lawns and shrubs survive the heat and the water cutbacks, MWD officials suggest residents give their outdoor plants and lawns a thorough watering two or three days before the pipeline is shut.
The MWD usually makes such repairs during the winter, when water demand is lower.
But MWD officials said the 96-inch pipeline that carries Northern California water to Three Valleys Municipal Water District and Inland Empire Utilities Agency was so badly worn from old age and heavy use that it could break if repairs were not made soon.
MWD provides nearly 60% of the water used by Three Valleys Municipal Water District and about 30% of the water needed by Inland Empire Utilities Agency.