SOUTHWEST RIVERSIDE COUNTY - Amid unseasonably dry conditions and the looming specter of water shortages in coming years, local water agencies are planning conservation measures, including calls for voluntary reductions in water use.

Representatives of the agencies say no crisis is imminent, and no local agencies are considering mandatory reductions in the foreseeable future. But the near-drought and an August court order to cut deliveries from the Sacramento-San Joaquin River Delta have shaken the agencies into planning for rough times ahead.

Local supplies also have dwindled somewhat because of scant rainfall. The Temecula area got just four inches of rain in the 12 months through June, compared with an annual average of 14 inches in the previous six years.

With less precipitation and more evaporation, grape and avocado growers, especially, have had to rely more heavily on irrigation, which is fed partly by the imported water.

The Elsinore Valley Municipal Water District, for example, recently approved a plan to ask its customers to reduce water use by 10 percent. Western Municipal Water District expects to roll out a conservation-awareness plan that could include decals on service trucks and reminders slipped into bill envelopes, spokeswoman Tedi Jackson said.

Western, a larger agency that serves the Elsinore district and customers in neighboring areas to the north and west, is holding back until it is able to coordinate the program with the Eastern Municipal Water District, which serves parts of Perris, Menifee and French Valley, Jackson said. The coordination will make it easier to convey the conservation message without leaving customers thinking that one has merely adopted a new set of slogans.

"It's confusing for customers," Jackson said. "That's why we want to work together."

The Rancho California Water District has recently begun charging escalated rates for some customers that have exceeded certain voluntary thresholds. The district plans no additional cutbacks, voluntary or otherwise, a spokesman said.

That district draws water not only from Western Municipal and Metropolitan, but also from an exceptionally large underground aquifer, limiting its vulnerability to the ebbs and flows of water from the delta and from the Colorado River, the two main sources for Southern California.

Rancho California spokesman Tim Barr said the district has targeted its heaviest water users for the last three years with mailings and talks encouraging them to cut back.

"We're actually seeing a reduction in our landscaping water use," Barr said.

Barr said the district also is beginning to see the first effects of Senate Bill 1881, passed this summer, which prevents homeowners associations from mandating thirsty grass over native plants and other ground coverings that use less water.

And the district's board of directors recently cut its base line, the monthly threshold at which a customer begins paying a higher water rate each month. Lower thresholds translate into higher bills.