Rainfall boosts California’s dwindling water supplies
By Rebecca Kimitch, Staff Writer, rebecca.kimitch@sgvn.com
Posted: 12/24/2010 10:21:50 PM PST The storms that brought flooding and destruction to the region last week had something of a silver lining, at least to water managers. The rains went a long way to refueling water supplies that were precariously low after three years of drought. More than nine inches fell in six days – half the region’s annual average. “This is a great boon and a fantastic way to start the water year. It is an outstanding start,” said Shane Chapman, general manager of the Upper San Gabriel Valley Municipal Water District. How much of the rainwater has been captured for future use won’t be known for weeks or months. And regardless of how much is captured, some think more could have been done to keep water from flowing to the Pacific Ocean. At this time last year, the water level in the Main San Gabriel Groundwater Basin – the giant aquifer that lies below the Valley and provides much of its water – was at a historic low. Rains earlier this year have since improved the level, but it’s still lower that water managers want. “This rain is great for our water supply,” said Carol Williams, executive director of the Main San Gabriel Basin Watermaster. “This is going to really, really benefit us.” … Since Oct. 15, the county has collected more than 42,000 acre-feet of water for percolation. That’s 20 percent of the total amount it usually puts into the ground every year. An acre-foot can supply two families with water for a year. Besides the local supplies, the more than 17 feet of snow that fell in parts of the Sierra Nevada last week means that water imported from the North also will be easier to come by. … Last year, three years of drought had left water supplies so low that state water managers gave an initial allocation predicted at a mere 5 percent of requests – the lowest in four decades. That allocation was later increased. Now state water projects’ reservoirs are all at near-normal storage levels for this time of year. But Debra Man, assistant general manager and chief operating officer for the Metropolitan Water District, which is charged with distributing imported water to Southern California, is only cautiously optimistic. It will be months before she breathes a sigh of relief. “It’s great that early in the winter season we are getting major storms and snowfall, but we have also experienced in the past … you can have an early, heavy above-normal rainfall, precipitation and the rest of the winter months become dry,” she said. And no matter how much it rains here, Southern California is still facing two serious threats to its water supply. First, a 12-year drought continues on the Colorado River and the largest reservoir it feeds, Lake Mead, is still at record lows. Second, concern over the habitat of the San Joaquin-Sacramento River Delta has led to court-ordered limitations in how much water in Northern California can be pumped south. “Whereas in past droughts, we were able to recover reserves during one or two seasons, now, with the pumping restrictions, we are unable to do that,” MWD spokesman Bob Muir said. So despite the rains, water officials continue to stress the need for conservation. …
