When water use goes down, water prices go up. It’s a maddening paradox San Diegans have dealt with for the past year. When Gov. Jerry Brown last year ordered Californians to use 25 percent less water, water agencies saw their sales plunge and holes open up in their balance sheets. So they raised rates. Short showers, brown lawns and dirty cars were rewarded with stubbornly high bills.The state recently relaxed those water rules because rain and snow this winter refilled rivers and reservoirs.