Stress on Supply System Cited : Water Conservation Measures Are Urged by Agency

County officials cautioned Thursday that water supplies may not be as abundant as usual this summer if residents fail to conserve water--especially on warm, sunny days.

Because the water supply system is already under unusual and excessive stress for this early in the year, some of the county’s 24 water agencies may be unable to get the amount of water they need when they need it, which could result in diminished deliveries to customers, according to Robert Melbourne, chief engineer for the San Diego County Water Authority.

Noting that some rain-filled reservoirs are as much as 80% below capacity, Melbourne said the water authority would expand its ongoing campaign to educate the public on the importance of conservation.

Demand at All-Time High

“We’ve never had a year like this before,” Melbourne said, explaining that demand is at an all-time high, putting unprecedented pressure on the county’s complex water system. “This is critical. If we have any kind of disruption, a broken line or something like that, some of our agencies would be hurting pretty badly.”

Melbourne said water supplies will hold through the summer and no one should lose deliveries, but conditions could worsen next year if the winter is dry.

Already, the aqueduct system has been “under strain” and turned on at “full blast” 11 days since May 1. Normally the system would not reach that stressful peak until next month, Melbourne said.

The county depends on two types of reservoirs: those that rely on imported water supplied by the aqueduct system and those dependent on rainfall. They are used in an interconnected distribution system.

When rain-filled reservoirs are at levels too low to meet demands--which is the case now-- the shortfall is met by water taken from the aqueduct system. Other reservoirs are also forced to take up some of the burden. The increased use of the aqueducts is what overloads and “taxes” the system, Melbourne said.

Peak Demands

Although San Diego County officially is alloted 545,000 acre-feet of water from the Colorado River and state water project, it actually uses almost twice as much when the Colorado River has a surplus, as it does now. The county expects to receive about 1 million acre-feet of water this year.

“We have our peak demands (for water) on the warmest days,” Melbourne said. “If everybody could just take in water on a uniform basis every day of the week, we’d be pretty much OK.”

Melbourne advised that people should not waste water on warm days, and should watch their irrigation systems or lawn watering habits closely.

Some of the county’s 24 water agencies have already begun mailing flyers on water conservation with their customer’s monthly bill. School visits, television commercials and bus billboard space will be increased to reach more people, Melbourne said.

Melbourne said most of the depleted reservoirs are low because there was little runoff this winter and spring: “It (was) just absorbed by the soil.”

National Weather Service forecaster Frank Perdue said the total rainfall for this season so far has been 9.61 inches, slightly over the 9.32 average.

Melbourne said solutions to an overloaded water system will come with capital improvements involving three to five years of planning and building. But the more immediate goal, he said, is to educate the public.