Proposed well water fee for rural residents in Santa Rosa groundwater basin is $20 a year

Rural residents using well water in the sprawling Santa Rosa Plain would pay about $20 a year under a state-mandated program aimed at protecting groundwater for the next 50 years.

The 10-member board that governs the agency overseeing Sonoma County’s largest groundwater basin favors a regulatory fee structure based on the estimated amount of water well owners pump from the ground, officials reported at a virtual community meeting Wednesday night.

“The board’s preferred option is a fee based on groundwater use,” said Susan Harvey, vice chair of the Santa Rosa Plain Groundwater Sustainability Agency and vice mayor of Cotati.

The fees, she said, would support work to “ensure that our groundwater basin doesn’t run out of water, particularly as we face an ongoing drought and the effects of climate change.”

Harvey noted groundwater overpumping had caused land in San Joaquin County, in the heart of California’s Central Valley, to sink by more than six feet from 1988 to 2016.

The sustainability program was mandated by a 2014 state law requiring 94 of California’s 515 groundwater basins to develop sustainability plans for the next half-century, including blueprints to respond a 20-year drought.

“The more you pump the more you pay,” said Jerry Bradshaw, an agency consultant, describing the proposed fees.

The board rejected three other proposals for covering the nearly $1.1 million annual cost of operating the agency, including administration, projects, monitoring and closing gaps in data on groundwater use.

A proposed flat fee per well, a parcel tax and a benefit assessment district — the last two requiring voter approval — were rejected by the board.

“Cheap insurance,” one online participant said of the $20 fee, according to Sam Magill, the facilitator.

Participants posed questions off-camera that were answered by agency staff.

Assuming rural residents use a half-acre foot of water a year, or 446 gallons of water per day, their fee would be about $20 a year.

A 50-acre vineyard, using 30 acre feet per year, would pay $1,200, and a 100-acre pasture, using four acre feet per year, would pay $160, Bradshaw said.

An acre-foot is the amount of water it would take to cover a football field in one foot of water. An average California household uses between one-half to one acre-foot of water per year for indoor and outdoor use.

Agricultural water usage was based on crop types and acreage, which he said was “pretty good data,” while residential use was based on studies and local data.

The rates were calculated by dividing the revenue needed to operate the agency — $805,900 assuming 25% grant funding — by the total amount of water drawn from wells, he said.

Since 2017, the county and other local agencies, including cities and water districts, have paid the program costs for groundwater management and monitoring for the Santa Rosa Plain, the Petaluma Valley and Sonoma Valley basins.

Each of the three groundwater agencies has also received about $2.2 million in state grants and technical assistance.

Some elected officials want subsidy to continue to cover well water use.

Rural residents, who install and maintain their own wells, should not have to pay for the sustainability program, county Supervisor David Rabbitt has said, calling it “another unfunded state mandate.”

Rabbitt has proposed three funding options for the county’s 2022-23 budget, including one for $622,728 to offset the fees to be paid by residents in all three basins.

The largest of three major groundwater basins in Sonoma County, the Santa Rosa Plain basin stretches across the valley floor from Windsor to Cotati and from Sebastopol to east Santa Rosa.

Marcus Trotta, a principal hydrologist at Sonoma Water, the county’s water agency, said there was no evidence of problems in the Santa Rosa basin but limited information on groundwater resources.

Among the potential problems, he said, groundwater declines at high rates during drought, citing a 2,000-acre-foot annual loss during droughts compared with a 600-acre-foot loss under normal conditions.

The Santa Rosa basin board will hold a rate and fee study community meeting from 5:30 to 7:30 p.m. Tuesday at the Windsor Community Center, 901 Adele Drive, and another one during the same hours Wednesday at Santa Rosa Veterans Memorial Hall, 1361 Maple Ave.

The board is scheduled to adopt the sustainability fees June 9, in time to include them on the next property tax bill.

The Sonoma Valley basin board will hold a virtual rate and fee study community meeting via Zoom from 5:30 to 7:30 p.m. May 5.

The Petaluma Valley basin board will hold a rate and fee study community meeting from 5:30 to 7:30 p.m. May 12 with the location yet to be determined.

You can reach Staff Writer Guy Kovner at 707-521-5457 or guy.kovner@pressdemocrat.com. On Twitter @guykovner.