December 23, 2014 - SACRAMENTO – California’s hopes for ending one of its worst droughts in more than a century of recordkeeping hinge on the state receiving much more precipitation than normal in 2015. After three consecutive years of below-average snow and rainfall, surface and groundwater reservoirs are depleted. Surface reservoirs are unlikely to be recharged to normal levels unless precipitation and snowpack this water year are both well above historical averages.

Abundant snowfall in the mountains would be an important component of a drought-ending scenario. The Department of Water Resources (DWR) has scheduled the winter’s first manual measurement of the snowpack on December 30. Generally, California’s snowpack supplies about a third of the water needed by the state’s residents, agriculture and industry as it melts in the late spring and summer.

Due to several December storms, rainfall in Northern California so far this water year has been more than normal, but this precipitation has not generated greater-than-normal snowfall in the Sierra Nevada. The largest storm blew in from the south, and its warm temperatures resulted in less snowfall than might have been delivered by a colder storm.

Electronic readings of the snowpack show that its water equivalent is only 54 percent of average statewide for December 23. One December 30 manual measurement will be at the Phillips Station snow course off Highway 50 near Echo Summit. 

Water year 2014 ended on September 30 as the third driest such period on record; only 1924 and 1977 recorded less statewide precipitation. It was the driest year ever in the San Joaquin Valley, Central Coast and South Coast. This year also was the warmest year on record in California, according to the California Climate Tracker. These extraordinarily dry and warm conditions strengthened the drought’s hold on California, and reservoir storage continued to fall through most of 2014.

Shasta Lake, the state’s largest reservoir, normally holds nearly 2.8 million acre-feet (AF) of water in late December but today has only 62 percent of that average amount, 1.723 million AF. Due to the recent storms, Shasta’s storage has risen since November 29, when it held only 1.046 million AF, its lowest amount of the past quarter century. Similarly, Lake Oroville, a key reservoir of the State Water Project that normally holds more than 2 million AF in late December, today contains 1.267 million AF, only 59 percent of the average amount. The lake’s storage had fallen before the recent rains to 898,221 AF on November 21, its lowest storage since 1986.

DWR’s initial water allocation to the SWP’s 29 customers for 2015 was announced on December 1 as 10 percent, an increase from the five percent allocated for 2014. This winter’s precipitation will determine whether the allocation is changed in the months ahead. The 29 water contractors have requested 4,172,686 AF for 2015. One acre-foot is enough water to cover one acre to a depth of one foot; it can meet the needs of a typical California family of four for a year.

The final SWP allocation for calendar year 2013 was 35 percent of the slightly more than the 4 million AF requested. In 2012, the final allocation was 65 percent. It was 80 percent in 2011 after an initial allocation of 25 percent. The final allocation was 50 percent in 2010, 40 percent in 2009, 35 percent in 2008 and 60 percent in 2007. The most recent 100- percent allocation was in 2006.

News media reporters and photographers are invited to accompany DWR snow surveyors near Echo Summit on December 30. The location is Phillips Station at Highway 50 and Sierra at Tahoe Road, approximately 90 miles east of Sacramento. Measurements will begin at 11 a.m. Reporters and photographers should bring snowshoes or cross-country skis and park their vehicles along Highway 50 without blocking driveways or roads. The snow course is located on private property, and DWR therefore requests the media to remain off the property until the survey begins.

Electronic snowpack readings are available on the Internet at:
http://cdec.water.ca.gov/cdecapp/snowapp/sweq.action

Electronic reservoir readings may be found at:
http://cdec.water.ca.gov/cdecapp/resapp/getResGraphsMain.action

Electronic precipitation readings are at:
http://cdec.water.ca.gov/snow_rain.html

For a broader snapshot of current and historical weather conditions, see:

Water Conditions Page
http://www.water.ca.gov/waterconditions/waterconditions.cfm

Drought Page
http://www.water.ca.gov/waterconditions/index.cfm