With water officials bracing for a possible third consecutive dry year in California, the Department of Water Resources will conduct the season”s first snow survey on Friday.
This survey”s results likely will be far different than last winter”s initial readings which showed water content in the snowpack at 150 percent of normal for the date, just as California was turning dry after wet storms in November and December.
Today”s scant snowpack dramatically illustrates the result of the near-record dry weather we have had since last January. Statewide electronic readings indicate that today”s snowpack water content is only 20 percent of normal for the date.
The snowpack normally provides about a third of the water we use in California as it slowly melts into streams and reservoirs in spring and early summer.
Manual readings taken by DWR and scores of cooperating agencies on Friday and on or about the first of each month through May will augment and check the accuracy of real-time electronic readings.
A traditional center of attention each manual snow survey date is the measurement site off Highway 50 near Echo Summit. The 11 a.m., Friday readings there should be publicly available by early afternoon.
Although anticipating dismal water content readings this week, DWR weather watchers note that it”s early in the season and this winter could still turn out average or wet.
The concern, however, is that irrigation-dependent San Joaquin Valley farms and some other areas will suffer if we go into a third consecutive dry year without the cushion of reservoir storage that we had this calendar year (2013) due to the storms in late 2012 before California began sliding toward drought. A third dry year would also bring continued higher wildfire risks.
Lake Oroville in Butte County, the State Water Project”s principal reservoir, today is at only 41 percent of its 3.5 million acre-foot capacity (66 percent of its historical average for the date). Shasta Lake north of Redding, California”s and the federal Central Valley Project” largest reservoir, is at 37 percent of its 4.5 million acre-foot capacity (58 percent of average for the date). San Luis Reservoir, a critical south-of-Delta reservoir for both the SWP and CVP, is a mere 29 percent of its 2 million acre-foot capacity (43 percent of average for the date) due both to dry weather and Delta pumping restrictions last winter to protect salmon and Delta smelt. Delta water is pumped into the off stream reservoir in winter and early spring for summer use in the Bay Area, San Joaquin Valley, Central Coast and Southern California.
The continuing dry weather prompted DWR Director Mark Cowin on December 13 to mobilize a drought management team “to offset potentially devastating impacts to citizen health, well-being and our economy.”
Gov. Jerry Brown has united DWR and other agencies in an Interagency Drought Task Force.
DWR and other agencies will streamline transfers of water from areas of relative abundance to areas of critical need, monitor water supply impacts in small rural communities whose groundwater sources are stressed by prolonged dry conditions, and take other steps to mitigate the effects of dry weather.
In November, DWR announced an initial allocation of only five percent of the amount of State Water Project water requested for calendar year 2014. Although the initial allocation is an early-season, conservative estimate of how much water DWR anticipates it will be able to deliver, the five percent initial estimate for 2014 and for calendar year 2010 are the lowest ever.
The 2010 initial allocation, made on the heels of the 2007-2009 drought, was eventually increased by winter storms to 50 percent of the slightly more than 4 million acre-feet of water requested by the 29 public agencies that collectively deliver water to more than 25 million Californians and nearly a million acres of irrigated farm land.
The final SWP allocation for calendar year 2013 was 35 percent of the slightly more than 4 million acre-feet requested. In 2012, the final allocation was 65 percent. It was 80 percent in 2011, up dramatically from 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 last 100 percent allocation – difficult to achieve even in wet years because of Delta pumping restrictions to protect threatened and endangered fish – was in 2006.
