This story originally appeared on PressDemocrat.com, also part of the Sonoma Media Investments news network.

One of Sonoma County’s newest and most obscure public agencies is scheduled Thursday to consider fees for residents, ranchers and businesses who use well water in the Santa Rosa Plain.

The nine-member board of the Santa Rosa Plain Groundwater Sustainability Agency will consider the fees at a public meeting Thursday afternoon at the Santa Rosa Water office, 35 Stony Point Road.

The meeting will start with a discussion of the proposed fees at 1 p.m., with official consideration of a groundwater ordinance no earlier than 2 p.m.

Established two years ago in compliance with state law, the agency is responsible for sustaining the quality and quantity of underground water in the plain, which is generally the valley floor from Cotati to Windsor and from the foot of Sonoma Mountain to Sebastopol.

The proposed fees are intended to cover the agency’s $337,000 annual operating costs.

Rural residents who rely solely on well water would pay $8 to $13 a year. All rural landowners are assumed to use a half-acre-foot (162,925 gallons) of groundwater annually.

State law prohibits mandatory metering on wells used for homes, gardens and landscaping — but not for commercial purposes — that use less than 2 acre-feet of water per year.

Larger water users, including cities, towns, mutual water companies, wineries, farms, businesses, school and golf courses, would pay $16 to $26 per acre-foot (325,851 gallons).

Fees for those with metered wells would be calculated on actual water use, averaged over a five-year period.

Large water users without meters, primarily farms, would pay a fee calculated by multiplying the number of irrigated acres by the estimated annual water use for specific crop types.

Residents and businesses that only use water from a city, town or mutual water district are exempt from the fee.

The agency estimates that agriculture uses about one-third of the groundwater in the Santa Rosa Plain, cities and towns use another third and rural residents use about one-fourth. The remainder is used by mutual water companies, schools, golf courses and other commercial entities.

If the local agency does not adopt fees and cannot complete a groundwater sustainability plan, the state could step in and impose fees that would range from $100 a year for residential well owners to a $300 base fee plus $40 per acre-foot for cities, farms and other large users.

The ordinance would also establish a well registration program, under which the agency would send letters to all residents and businesses in areas without a public water system and ranchers who are assumed to have a well, advising them they will be registered.

An appeals process will be established for landowners who receive a letter but don’t have a well.

This story originally appeared on PressDemocrat.com, also part of the Sonoma Media Investments news network.