Valley residents packed Vintage House’s Stone Hall Monday evening with concerns over the impact of the drought and declining groundwater throughout the area.
The meeting, organized by 1st District Supervisor Susan Gorin and the Sonoma County Water Agency, featured regional water experts and members of local agencies working to assuage dwindling water supply worries. It was the first of several town halls being held throughout the county to address water concerns.
Gorin, who said she had been planning the meeting before the severity of the drought was known, and intended to address the decline of Valley groundwater, noted that the drought has exacerbated the diminishing water supply issue and it is even more important that the community and its representatives work together to find solutions. “Sonoma Valley is facing water supply issues that need to be dealt with right now, proactively,” Gorin said.
Sonoma County Water Agency Chief Engineer Jay Jasperse explained that despite recent rains, California is in one of the worst drought situations in its history, with relatively dry weather starting in 2012. He said the area’s water supply, which comes a “long distance,” principally from the Russian River through pipelines from the Lake Sonoma reservoir, but also from groundwater, is increasingly vulnerable.
The water agency, Jasperse said, is working to increase the water supply by expanding the water portfolio, maximizing conservation and balancing surface water levels and groundwater levels.
Japserse, who noted the water agency is working with the National Oceanic and Atmospheric Association and the United States Geological Survey to better forecast weather patterns as they relate to managing water supply, said the Valley’s resources are more vulnerable than those in other regions and right now, they are out of balance.
A 2006 USGS study in Sonoma Valley showed declining groundwater supplies, particularly in deep aquifers in southern parts of the area. Some of these deep aquifers are declining at alarming rates, water agency hydrogeologist Marcus Trotta said Monday. When water in the aquifers falls below sea level, it becomes susceptible to salt water intrusion, Trotta explained, increasing the salinity of the supply and making it not potable.
In Sonoma Valley, Trotta said, 60 percent of the total water demand is met by groundwater. Of that 60 percent, 53 percent is used for irrigation and 27 percent is used for rural residential needs.
California is one of the only states in the country that does not regulate groundwater.
With so little rainfall this past year, Jasperse and Trotta said, and the water supply levels in SCWA-managed reservoirs at historic lows, the diminishing groundwater supply has become even more worrisome.
According to Jasperse, while research results differ on whether future years will be wetter or drier, all results indicate the temperature will get warmer due to global warming. The results, he said, all show that weather patterns will be more variable, making it even more difficult to prepare for inclement weather.
The increased weather variability will increase demand, Jasperse said, and drier soils will lessen the ability of the ground to recharge the groundwater supplies.
“We need new solutions to build resiliency and protect the ecosystem,” Trotta said. “Community involvement is essential.”