The driest March and early April in 70 years has turned what was looking like a wet year into a near-drought for California. The water supplies in Pardee and in the Camanche flood control reservoir in Amador County are decreasing. The East Bay's largest water supplier is likely to impose mandatory rationing next month that could include higher water rates, limits on outdoor sprinklers or possibly a ban on car washing. In the San Joaquin Valley, hundreds of thousands of acres of farmland are being fallowed. The problem is a wicked combination of dry weather, low reservoir levels and a court ruling last year that limits Delta pumping to protect endangered fish. Following powerful January storms and a decent February, the recent dry stretch and its potential to affect statewide water supplies may come as a surprise. But it was the sixth-driest March in 89 years, according to state water managers. And the U.S. Bureau of Reclamation said the period from March 1 to mid-April was the driest such span in 70 years. The East Bay Municipal Utility District, which serves 1.3 million people in Contra Costa and Alameda counties, is dependent on snow in the Mokelumne River basin. That basin had its second-driest March since East Bay MUD began in 1923, and it is shaping up as possibly the driest April over that time, district spokesman Charles Hardy said. The North Fork of the Mokelumne River, located in the California Sierra Nevada Mountains, is also the primary source for the Central Amador Water Project system, although there have been no reports of a planned rationing by the Amador Water Agency.