With rivers roaring and more rain coming, California’s drought cops are wrestling with a complicated question: Should they keep patrolling the beat? A chorus of urban water districts Wednesday urged the State Water Resources Control Board, California’s chief drought regulator, to allow the state’s emergency conservation rules to expire. At a lengthy hearing in Sacramento, representatives of the water districts said the state board is losing credibility by insisting the drought still exists when residents can see how much conditions have eased.