With severe drought conditions plaguing California and a decreasing groundwater supply in Sonoma Valley, water supply is a top concern for the Sonoma County Water Agency and area agricultural producers.
Since Jan. 1, 2013, Sonoma has received only 7.6 inches of rain. Normally, the Valley gets 33 inches of rain in a calendar year.
With no precipitation in sight over at least the next two weeks, water agency Chief Engineer Jay Jasperse said drought conditions are real in the Valley. Ukiah and Mendocino County are the driest they’ve been since 1894, Jasperse notes, while Sonoma is experiencing the third driest year on record.
And drought seems to be affecting all of California, with record low rainfall throughout the state. On Dec. 9, Democratic Sen. Dianne Feinstein and Republican Rep. Jim Costa asked Gov. Jerry Brown to declare a statewide drought and call on President Barack Obama to make a federal declaration. The Congressional members wrote, “… we believe it would be prudent to declare a state drought emergency now and to request a broad federal disaster from the president as soon as possible.”
After two dry years, in June 2008 and February 2009, Gov. Arnold Schwarzenegger declared a statewide drought. In March 2011, after a wet year, Brown rescinded that drought declaration.
But the Congress members explained, “After two years of dry conditions, we are faced with these challenges once again.”
If the governor declares an emergency drought situation, it would activate the state’s emergency plan and activities such as water conservation, water transfers and close weather monitoring will begin. If a presidential emergency is issued, the state will receive disaster relief from federal agencies.
On Wednesday, Dec. 18, Brown asked staff from state water, agriculture and emergency services agencies to form a drought task force and advise him on whether to make an emergency drought declaration.
Japserse said if the government does declare an emergency drought, the water agency, which is separate from the state’s water project, will not be directly impacted, though there may be some benefits for agricultural producers.
The water agency, which is headquartered in Santa Rosa, was created in 1949 as a special district by the state legislature and provides flood protection, water supply services, water sanitation and wastewater disposal. The agency sells water in Sonoma and Marin counties and contracts with the Valley of The Moon Water District and the City of Sonoma. The agency also manages 14 groundwater basins in the county, with six wells, and runs a volunteer well-monitoring program in the Sonoma Valley.
“We have this drought condition overlain with groundwater depletion areas we have seen, so it’s going to make this interesting in Sonoma Valley over the next year,” Jasperse said.
But extremely low water storage levels in Lake Mendocino, one of SCWA’s two reservoirs, are“the most immediate worry,” according to Jasperse.
The water agency is petitioning the state’s Water Resources Control Board for a temporary order to change the management regime governing operation of the water supply in Lake Mendocino to allow for more flexibility in the timing and volume of water releases. The hope is to better distribute water to people and fish in the area. The agency is also working on projects to look at water supply reliability and study weather patterns to better forecast drought and flood conditions, allowing the agency to better prepare for dry (or wet) seasons.
Marcus Trotta, SCWA hydrogeologist, said the agency’s other reservoir, Lake Sonoma, which supplies water to the Valley, Santa Rosa, southern Sonoma County and northern Marin, is much larger and in better condition, at nearly 70 percent full.
And drought is only one of the Valley’s water challenges. Over the last decade, groundwater levels have been declining in the Sonoma Valley, Trotta said, noting Sonoma, El Verano and unincorporated areas southeast of Sonoma are seeing the largest decreases of a few feet per year. The decreasing groundwater levels, especially in Sonoma Valley, Jasperse said, are not just a factor of drought, although decline is certainly “exacerbated” because lack of rain has not recharged aquifers.
While some shallow wells are drying up, it’s actually the deeper aquifers that are experiencing the most decreases. SCWA is conducting a number of studies to simultaneously examine the cause of decline and boost the supply of groundwater.
The only option in many cases, he said, may be to dig deeper wells, further depleting deep aquifers.
Trotta said he hopes the water agency will find a more long-term solution to creating more water supply options and reducing demand. The agency is currently focusing on using storm water to recharge groundwater supply by building ponds and contouring lands so water flows over it in such a way that it permeates the ground.
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