Drought depletes California snowpack, aquifers
SACRAMENTO — Drought in California is taking its toll both above and below ground as a minuscule amount of snow remains in the mountains and aquifers in many areas are becoming depleted.
The state Department of Water Resources’ final snow survey of the year on May 1 found the water content at just 18 percent of normal for the date despite early spring storms that raised hopes for at least a little relief from the dry conditions.
The previous survey on April 1 found a snowpack that was about one-third its normal size, so April brought precious little new snow as warming weather began to melt what was there into streams and reservoirs.
“I do know the storms made a big difference in the reservoirs, but they’re still so far below normal,” DWR spokesman Doug Carlson told the Capital Press.
Lake Oroville in Butte County, the State Water Project’s principal reservoir, was only at 53 percent of its 3.5 million acre-foot capacity and 65 percent of its average for the date as of May 1, according to DWR gauges. Shasta Lake, the federal Central Valley Project’s centerpiece, was also at 53 percent of capacity.
The snow survey came on the heels of a DWR report that groundwater resources throughout California are at historically low levels, according to surveys by local water districts. Aquifers nearly everywhere are down from last year, and the greatest number of deepened wells is in the fractured bedrock foothill areas east of Sacramento and in the Kaweah and Kings subbasins in the San Joaquin Valley, according to the report.
The report will form the basis for attempts to improve groundwater monitoring and oversight where there are gaps, a DWR news release explained. However, no state-imposed restrictions on drilling or groundwater use are imminent, said Mary Scruggs, a supervising engineering geologist for the agency.
Such limits “would and should be handled at the local level” by water districts and counties, Scruggs said in an email. The DWR is working with county agencies to make sure well drillers submit logs for newly constructed and deepened wells in a timely manner to help water managers keep track, the release stated.
Some water districts did include readings taken after the February and March storms in the report, she said. But the extent to which the storms helped aquifers is hard to know, partly because it can take a long time for rainwater to seep through soils and recharge them, she said.
Snowpack runoff and groundwater are two key resources as many farmers are already reeling from a lack of available surface water this spring. California Citrus Mutual recently asserted that as many as 50,000 acres of citrus trees could be forced out of production within the Friant Division Service Area from Merced to Bakersfield, where a vast majority of the valley’s $1.5 billion citrus industry operates.
Many growers have said they’ll rely on groundwater to get through the season. The DWR estimates that groundwater could contribute as much as 60 percent of the overall water use statewide this year, Scruggs said.
Snowpack readings: http://cdec.water.ca.gov/cdecapp/snowapp/sweq.action
Reservoir levels: http://cdec.water.ca.gov/cdecapp/resapp/getResGraphsMain.action
Water conditions: http://www.water.ca.gov/waterconditions/
DWR drought page: http://www.water.ca.gov/waterconditions/drought/