California’s snowpack still measures far below average despite the state’s recent band of storms, suggesting that the summer snowmelt runoff will offer little relief during the current drought.
Today, snow surveyors with California Department of Water Resources conducted the first snowpack reading of spring, finding that the Sierra snowpack is just 32% of normal. The April 1 reading is considered a bellwether for how much water runoff will be available in the coming dry months of summer for farms and communities.
“We’re already seeing farmland fallowed and cities scrambling for water supplies,” DWR Director Mark Cowin said in a prepared statement after the snow survey results were released. “We can hope that conditions improve, but time is running out and conservation is the only tool we have against nature’s whim.”
February and March storms brought some promise to the state after the record-breaking dry months of December and January, but the recent rains have not broken the drought’s three-year grip as reservoirs, rainfall totals and the snowpack remain critically low.
Today’s manual and electronic readings – taken when snowpack normally is at its peak before melting into streams and reservoirs – record the snowpack’s statewide water content at just 32% of average.
Electronic readings indicate that snowpack water content in the state’s northern mountains is 23% of normal. The electronic readings for the central and southern Sierra are 38% and 31% of normal, respectively.
Reservoirs also are at precipitously low levels. Lake Oroville in Butte County, the State Water Project’s (SWP) principal reservoir, is at only 49% of its 3.5 million acre-foot capacity (64% of its historical average for the date). Shasta Lake north of Redding, California’s and the federal Central Valley Project’s (CVP) largest reservoir, is at 48% of its 4.5 million acre-foot capacity (60% of its historical average). San Luis Reservoir, a critical south-of-Delta reservoir for both the SWP and CVP, is a mere 42% of its 2 million acre-foot capacity (46% of average for this time of year) due both to dry weather and Delta pumping restrictions to protect salmon and Delta smelt.
Snow surveyors from DWR and cooperating agencies manually measure snowpack water content on or about the first of the month from January through May to supplement and check the accuracy of real-time electronic readings. This year’s final manual survey is scheduled for May 1.
On January 31, after the winter’s dismal snow surveys, DWR set its allocation of SWP water at zero. The allocation has not been increased.
The only previous zero water delivery estimate was for agriculture in the drought year of 1991, but cities that year received 30% of requested amounts.
Despite the “zero” allocation, DWR has continued to deliver water essential for health and safety and nearly all people and areas served by the SWP also have other sources of water.
Deliveries could still be boosted by improving hydrology.
The final SWP allocation for calendar year 2013 was 35% of the slightly more than 4 million acre-feet requested by the 29 public agencies that collectively supply more than 25 million people and nearly a million acres of irrigated farmland. In 2012, the final allocation was 65% of the requested 4 million acre-feet. It was 80% in 2011, up dramatically from an initial allocation of 25%. The final allocation was 50% in 2010, 40% in 2009, 35% in 2008, and 60% in 2007. The last 100% allocation – difficult to achieve even in wet years because of Delta pumping restrictions to protect threatened and endangered fish – was in 2006.
Although 2013 was the driest calendar year on record for much of California, last-minute November and December storms in 2012 – the first year of the current drought – replenished major reservoirs to somewhat mitigate dry conditions. That reservoir cushion is now gone.
This year is on track to perhaps be California’s fifth or sixth driest year, with its final ranking to be determined.
Electronic snowpack readings are available here. Electronic reservoir readings may be found here.
For a broader snapshot of current and historical weather conditions, see DWR’s “Water Conditions” and “Drought” pages.
(photo: Snow surveyors with DWR measure the Sierra snowpack’s water content on April 1, 2014.)