One storm event doesn’t make a water year….or does it?
Several California Dept Of Water Resources indexes published this week after a 5 day sequence of storms pounded northern California showed these storms had consequences. A jump in the Northern Sierra Precipitation Index of 8 stations shows rainfall so far this water year is now ahead of the 1982-83 year – the wettest on record.The index which sat at only 5 inches of rain as of late November jumped to 22 inches as of December 3.The index includes Shasta dam that saw 15 inches of rain.
The index is 212% of average for this date for the water year that runs Oct 1 thru Sept 30,2013.
Further south, the 6 station San Joaquin Valley index which includes Huntington Lake on the San Joaquin River, now sits at 150% of normal for this date after a pulse of 6 inches blew into the central Sierra from the 5 day event. This index is also ahead of the 82-83 year.
All in all – a nice start for year where expected rainfall was anyone’s guess.
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The Assoc of California Water Agencies website posted a story this week as follows:
The rains that have pounded parts of California in recent days have boosted water levels in state reservoirs, raising water storage in Oroville Reservoir—the State Water Project’s primary reservoir – by more than 300,000 acre feet, according to a statement released Dec. 3 by the State Water Contractors.
“This weekend’s storms gave a needed boost to California’s water conditions – storage is up in key reservoirs, which will help us get through potential dry spells in 2013,” Terry Erlewine, general manager of the State Water Contractors, said in a statement. “We are by no means out of the woods, but the hope is that we will get enough precipitation throughout the winter to bring State Water Project allocations up to a reasonable amount.”
Last week, the California Department of Water Resources announced that the initial allocation for State Water Project supplies is 30%. Initial allocation estimates are typically conservative and state officials expect the allocation to increase as the winter season progresses. In 2012, State Water Project contractors received 65% of their contracted amount of water.
Water data compiled by DWR and listed here reveal higher than average water storage levels in reservoirs across the state. Reservoirs have shown large increases in storage in recent days due to the series of storms. For instance, Folsom reservoir has increased by more than 100,000 acre feet from Nov. 29 to midnight Dec. 2. It is at 50% of capacity and 104% of its average capacity, according to DWR data available at the California Data Exchange.