California on Wednesday suspended its mandatory statewide 25 percent reduction in urban water use, telling local communities to set their own conservation standards after a relatively wet winter and a year of enormous savings in urban water use. The new rules are a sharp change in policy for a state struggling to manage one of the worst droughts in its history. They came after a winter in which El Niño storms fell short of what meteorologists projected — particularly in the southern part of the state — but still partly filled parched reservoirs in Northern California and, more critically, partly replenished the mountain snowpack that provides water into the spring and summer. The state has long struggled to find ways to get water in the north to the people in the south. The state's two largest and most important reservoirs are both above their historical averages for this time of year. But reservoirs farther south remain far below average. "The snowpack this year was close to historical levels. But warm weather has melted a lot of it away," said Michael Anderson, the state climatologist. However, the rules do not apply to agriculture, which is covered by different regulations and makes up the bulk of water use in the state. State officials said that the drought, already in its fifth year, was not over and that Californians had to adapt to permanently more arid times because of climate change. Even as officials eased up on the regulations, the state made permanent prohibitions against washing down sidewalks and driveways, using a hose without a shut-off valve to wash cars and banning the use of water on road medians. Under the new rules, which take effect on June 1, communities would set reduction guidelines based on their own projection of water supplies, assuming that the next three years here continue to be uncommonly dry.