Sacramento, CA…– Department of Water Resources (DWR) hydrologists today
announced that water content in California’s mountain snowpack is 165 percent of
the April 1 full season average.
“Recent storms have significantly contributed to the above-average snowpack,
helping to stabilize California’s water supply for the year,” said DWR Director Mark
Cowin. “While this is beneficial for California’s farms, businesses and communities,
we remind residents to practice sensible water use and conservation as we
transition to warmer weather.”
After the snowpack readings were in, Governor Jerry Brown officially rescinded
former Governor Schwarzenegger’s emergency proclamations and executive order
issued in 2008 and 2009 relating to water shortage associated with the drought.
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.
Today’s manual survey and electronic readings are the most important of the year,
since April 1 is when the state’s snowpack normally is at its peak before it melts into
streams and reservoirs in the spring and summer months.
March precipitation has helped register 2011 among the top years in snowpack
water content, despite dry weather conditions in January and early February.
The mountain snowpack provides approximately one-third of the water for
California’s households, industry and farms as it melts into streams and reservoirs.
Results of today’s manual readings by DWR off Highway 50 near Echo Summit are
Location Elevation Snow Depth Water Content
% of Long Term
Alpha 7,600 feet 151.4 inches 57.9 inches 173
6,800 feet 124.2 inches 43.5 inches 154
Lyons Creek 6,700 feet 153.6 inches 56.1 inches 180
Tamarack Flat 6,500 feet 121 inches 45 inches 166
Electronic readings indicate that water content in the northern mountains is 174
percent of the April 1 seasonal average.
Electronic readings for the central Sierra show 163 percent of the April 1 average.
The number for the southern Sierra is 158 percent. The statewide number is 165
On March 1, the date of this winter’s third manual survey, percentages of the
snowpack’s normal water content were 109 percent of the full season average, 103
percent for the northern Sierra, 106 percent for the central Sierra, and 119 percent
in the south.
On this date last year, snowpack water content readings of the April 1 average were
123 percent in the north, 88 percent in the central ranges, 102 percent in the south,
and 102 percent statewide.
California’s reservoirs are fed both by rain and snowpack runoff.
A majority of the state’s major reservoirs are above normal storage levels for the
date. Lake Oroville in Butte County, the State Water Project’s principal reservoir, is
104 percent of average for the date (80 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 111 percent of average (91 percent of
DWR estimates it will be able to deliver 70 percent of requested State Water Project
(SWP) water this year. The estimate likely will be adjusted upward as hydrologists
make adjustments for snowpack and runoff readings.
In 2010, the SWP delivered 50 percent of a requested 4,172,126 acre-feet, up from
a record-low initial projection of 5 percent due to lingering effects of the 2007-2009
drought. Deliveries were 60 percent of requests in 2007, 35 percent in 2008, and 40
percent in 2009.
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.
The SWP delivers water to more than 25 million Californians and nearly one million
acres of irrigated farmland.
Statewide snowpack readings from electronic sensors are available on the Internet
Historic readings from snowpack sensors are posted at
Electronic reservoir level readings may be found at
The Department of Water Resources operates and maintains the State Water Project, provides dam safety and flood
control and inspection services, assists local water districts in water management and water conservation planning,
and plans for future statewide water needs.
Contact the DWR Public Affairs Office for more information about DWR’s water activities.