DWR hydrologists announced that water content in California's mountain snowpack is only 55 percent of the April 1 full season average.

"An unusually wet March improved conditions, but did not make up for the previous dry months,” said DWR Director Mark Cowin.  “The take-home message is that we’ve had a dry winter and although good reservoir storage will lessen impacts this summer, we need to be prepared for a potentially dry 2013."                                                     

Snowpack water content is measured both manually on or near the first of the month from January to May, and in real-time by electronic sensors.

This month’s survey and electronic readings are considered the most important of the year, since early April is when the state's snowpack normally is at its peak before it  begins to melt into streams, reservoirs and aquifers in the spring and summer months.

The mountain snowpack normally provides about a third of the water for California's households, industry and farms. 

Results of manual readings by DWR off Highway 50 near Echo Summit are as follows:

Location

Elevation

Snow Depth

Water Content

% of Long Term Average

Alpha

7,600 feet

44 inches

15.9 inches

48

Phillips Station

6,800 feet

Lyons Creek

6,700 feet

52.4 inches

19.1 inches

61

Tamarack Flat

6,500 feet

44.9 inches

13.6 inches

50

Electronic readings indicate that water content in the northern mountains is 78 percent of the April 1 seasonal average.

Electronic readings for the central Sierra show 51 percent of the April 1 average. The number for the southern Sierra is 39 percent. The statewide number is 55 percent.

On March 1, snowpack water content was only 34 percent of the April 1 average in the northern mountain ranges, 28 percent in the central Sierra, and 29 percent in the southern Sierra.  Statewide, the early March snowpack water content was 30 percent of the April 1 seasonal average.

On April 1 last year, snowpack water content readings were 173 percent of the April 1 average in the northern mountains, 161 percent in the central ranges, 155 percent in the south, and 163 percent statewide.

California has above average reservoir storage as summer approaches thanks to runoff from last winter’s storms.

Lake Oroville in Butte County, the State Water Project's principal reservoir, is 107 percent of average for the date (84 percent of its 3.5 million acre-foot capacity). Lake Shasta north of Redding, the federal Central Valley Project's largest reservoir with a capacity of 4.5 million acre-feet, is at 104 percent of average (86 percent of capacity).

DWR estimates it will be able to deliver 50 percent of the slightly more than 4 million acre-feet of State Water Project (SWP) water requested this year by the 29 public agencies that supply more than 25 million Californians and nearly a million acres of irrigated farmland.  An acre-foot is 325,851 gallons of water, enough to cover one acre to a depth of one foot. 

A 50 percent allocation is not severely low.

Wet conditions last year allowed the State Water Project to deliver 80 percent of the slightly more than 4 million acre-feet requested for calendar year 2011.  The final allocation was 50 percent in 2010, 40 percent in 2009, 35 percent in 2008, and 60 percent in 2007.  The last 100 percent allocation -- difficult to achieve even in wet years due to pumping restrictions to protect threatened and endangered fish -- was in 2006. 

Statewide snowpack readings from electronic sensors are available on the Internet

at http://cdec.water.ca.gov/cgi-progs/snow/DLYSWEQ

Historic readings from snowpack sensors are posted at

http://cdec.water.ca.gov/cgi-progs/rpts1/DLYSWEQ

Pick-a-Date snowpack water content readings are at

http://cdec.water.ca.gov/cdecapp/snowapp/sweq.action

Electronic reservoir level readings may be found at

http://cdec.water.ca.gov/cdecapp/resapp/getResGraphsMain.action

See DWR’s new Water Conditions page at:

http://www.water.ca.gov/waterconditions/