Amid drought, plan seeks to conserve aquifer under Santa Rosa Plain

Sonoma County supervisors on Tuesday are expected to adopt a far-reaching plan that seeks to locally manage and protect groundwater resources through scientific study and voluntary measures such as well monitoring.

The focus of the 314-page document is the 261-square-mile Santa Rosa Plain watershed, home to about half of the county’s population, including the cities of Santa Rosa, Windsor, Sebastopol, Cotati and Rohnert Park.

The plan emphasizes using science-based information to promote reduced water use, well monitoring, enhancing groundwater recharge and increased use of recycled water. It encourages participation and provides no penalties for non-compliance.

“We haven’t heard any naysayers at this point,” Supervisor David Rabbitt, the board’s chairman, said Monday.

The prolonged drought has focused attention on California’s groundwater supplies. Last month, Gov. Jerry Brown signed landmark legislation that requires local agencies develop sustainability plans for managing the resource or risk having the state intervene and assume that function.

Advocates of the Santa Rosa Plain management plan said Monday they hope it keeps Sacramento at bay.

“It’s really important in groundwater not to leave a vacuum for either Sacramento or the courts to come in and dictate how the local resource is managed,” said Jay Jasperse, chief engineer of the Sonoma County Water Agency.

The Santa Rosa Plain encompasses the flatlands between the Mayacmas Mountains east of Santa Rosa and the low hills west of Sebastopol, as well as upland areas. The Laguna de Santa Rosa runs along the west edge of the plain.

The plain has mostly recovered from heavy pumping from municipal wells in the Rohnert Park-Cotati area in the 1980s and ‘90s that lowered the underground water table as much as 100 feet, according to a 2013 survey of the area conducted by the U.S. Geological Survey. The agency credited the rebound to water conservation programs and a move to use more Russian River water for overcoming the “pumping depression.”

Rural pumping for residences and agricultural water supply now account for the majority of groundwater withdrawals, according to the draft management plan, which noted that modest reductions in groundwater levels can result in decreased stream flows and have adverse effects on ecosystems and habitat.

Rainfall is the main source of water inflow and groundwater recharge in the Santa Rosa Plain, which normally experiences average annual rainfall of about 40 inches. From July 2013 to July 2014, that amount was a paltry 18 inches.

Population growth and climate change are anticipated to place more strain on groundwater resources.

The Santa Rosa Plain management plan was developed over four years with input from 30 people representing the region’s governments, property owners and business, agriculture and environmental groups. Several participants said the collaborative process was a sharp contrast to contentious battles fought over the underground resource and key to gaining support for the plan, which is modeled on a program in place in Sonoma Valley since 2007.

“If anything, this should be the foundation for the next phase of development, which unfortunately is heading into a more regulated approach, which we are not for at all,” said Tito Sasaki, president of the Sonoma County Farm Bureau.

The total cost of the plan is pegged at $600,000.

Tuesday’s board meeting will include a public hearing.

You can reach Staff Writer Derek Moore at 521-5336 or derek.moore@pressdemocrat.com. On Twitter @deadlinederek.