Water could be rationed in San Diego as early as this summer due to the ongoing drought and a projected cut to deliveries to the region, Mayor Jerry Sanders warned Tuesday.The Metropolitan Water District of Southern California, which supplies most of San Diego's water, may soon slash deliveries to the region by as much as 20 percent, according to Sanders."If the cuts run as deep as we now anticipate, we would implement the water allocation strategy for local customers on July First of 2009, the beginning of the city's next fiscal year," Sanders said."Stiff penalties" would be imposed on customers who exceed the water allocated to them, he said.The mayor has scheduled three public workshops next month to discuss how to fairly implement water rationing.The 6 p.m. meetings will be held on Feb. 9 at the Otay Mesa-Nestor Branch Library; Feb. 10 at the Rancho Penasquitos Branch Library; and Feb. 12 at the War Memorial Building in Balboa Park.Alex Ruiz, assistant director of the Water Department, said rationing water is the best way to fairly achieve the city's conservation goals."Instead of telling folks what they can do, we give them a bucket of water and say `This is your allocation, stay within this and you will help us get to our demand reduction that the County Water Authority is asking for and you can use this water for whatever you want,"' Ruiz said. "Take longer showers, put it all on your lawn, it's your choice, but stay within this allotment."Ruiz said the amount of water allocated to individual customers would be based on customers' usage history. It would impact discretionary exterior water users more than customers who use water primarily inside the home, he said.People who have a lot of exterior water use for things like landscaping would be cut a "great amount," while small-time interior water users would not be impacted as much, according to Ruiz.Sixty percent of the water used by single-family residences in San Diego is for landscaping, he said.The need to cut back on water use in the city is necessitated by ongoing drought conditions and a judge's ruling that limits the amount of water that can be pumped from the Sacramento-San Joaquin River Delta in order to protect an endangered species of fish.San Diegans have cut back on their water use by about 5 percent since Sanders first raised the alarm by declaring a "Stage 1" water shortage emergency nearly a year ago.