Guy Kovner, THE PRESS DEMOCRAT
Sonoma County’s first experiment with underground drinking water storage is taking place at an unremarkable well drilled to 230 feet into the floor of Sonoma Valley.
Here, enough Russian River water to fill a large swimming pool — about 500,000 gallons — is now on deposit in a sand and gravel aquifer that lies beneath a thick lid of 8 million-year-old lava rock underlying part of the valley.
On Tuesday, crews began pumping water back out of the ground in the first round of testing under a $250,000 study of groundwater storage and recovery conducted by the Sonoma County Water Agency and the city of Sonoma.
The goal of the study, which started last month and will run through July, is to “verify and empirically determine” the feasibility of pumping plentiful wintertime surface water into the ground for extraction during dry summers, with increasingly volatile weather patterns expected as a consequence of climate change, officials said.
If the practice, known as groundwater banking, proves viable it “will make us a lot more resilient” as climate change forces the county to “ping pong between floods and drought,” said Jay Jasperse, chief engineer and director of groundwater management for the water agency.
Similar projects are underway around the state as water managers move toward integrated systems meshing surface water in lakes, rivers and behind dams with water stored in underground reservoirs, known as aquifers, he said.