California’s recovery from drought has been so remarkably quick that reservoirs on the verge of record lows just a year ago are now too full to handle more rain, prompting dam operators across the state to unleash surpluses of water not seen in years. The northern Sierra’s Feather River swelled with so much mountain runoff Tuesday that state officials considered shutting the road beneath Lake Oroville, California’s second largest reservoir, to allow dangerously swift waters to pour out the foot of the dam.