A series of rainstorms during the first three weeks of December boosted reservoir levels statewide and increased the Northern California snowpack, providing a welcome relief from more than three years of drought conditions. On Dec. 17, precipitation in San Diego was 205 percent of average for the "water year" to date (since Oct. 1), and it was 145 percent of average in the northern Sierra Nevada. In addition, the amount of water in the Northern California snowpack improved from 24 percent of average on Dec. 9 to 50 percent of average on Dec. 17.
While the storms were significant, the drought is far from over. State officials have said the wet weather would have to continue through the winter and produce 150 percent of average precipitation for the entire water year to recover from the drought. The initial 2015 allocation from the State Water Project -- an important water source for the San Diego region -- was set at 10 percent of requested supplies in early December. It's a very low initial allocation, though the figure may fluctuate up or down depending on precipitation over the winter.
One big benefit of the December dousing is that residents and businesses can turn off their outdoor irrigation systems at least through the end of 2014. A few rainy days can provide enough water for lawns and landscapes to survive for long stretches without irrigation, and they offer a valuable chance to save stored water supplies for next summer when water reserves will be even more important.
Outdoor watering accounts for more than half of a typical household's water use in California, and it has become a focal point for water conservation efforts. The Water Authority estimates that widespread participation in a voluntary two-week hiatus from using landscape watering systems across the region this month could save more than 5,500 acre-feet of water -- enough to serve about 11,000 families of four for a year.
Go to WheninDrought.org for more information about drought conditions, conservation resources and information about water-use rules by community.