State Increases 2012 Water Allocations to 65%

State Water Contractors got welcome news today when the Department of Water Resources announced it will deliver 65% of requested supplies this year, up from 60% estimated in April.

DWR actually downgraded its initial 60% supply forecast in November to 50% in February due to unusually dry conditions in the key winter months. However, a wet March and above-average reservoir storage boosted the allocation back up to 60% in April, and today’s increase to 65% is due to April’s wetter-than-usual weather.  

Wet conditions last year allowed the SWP to deliver 80% of requested supplies. The final allocation was 50% in 2010, 40% in 2009, 35 percent in 2008, and 60% in 2007.  The last 100% allocation – difficult to achieve even in wet years due to pumping restrictions to protect threatened and endangered fish – was in 2006.

April rainfall was 167% of normal in the mountainous area between the American River and Lake Shasta that produces much of California’s water supply.  The April rainfall total in the San Joaquin River basin was 137% of average.

Water content in this year’s sparse mountain snowpack was only 55% of normal on April 1, the time of year it’s usually at its peak. 

Reservoir storage has been the one consistent bright spot in the water supply picture this year.  Lake Oroville in Butte County, the SWP’s principal storage reservoir, is 99% full or 116% of average for the time of year. Lake Shasta north of Redding, the federal Central Valley Project’s largest reservoir, is 97% full and 110% of average for the date.