Sonoma County Municipal Code Art. VIII Well Monitoring and Water Conservation and Best Management Practices

Unless the conditions of approval for a discretionary permit require otherwise, the following metering and water level monitoring is required of all water wells for which an application is submitted after October 4, 2022, except for water wells that serve a single parcel that is solely used for residential purposes and with cumulative groundwater use of 2.0 acre feet or less of water per year:

(a) Groundwater Use Metering:

(1) Well Meter Records and Reporting. The owner or user of a well shall record readings from the totalizing water meter at least monthly, and shall report the readings to the enforcing agency annually by February 1 of the following calendar year.

(2) Meter maintenance. The owner or user of a well shall maintain the totalizing water meters in good working order and calibrate meters at least once every five (5) years. Maintenance and calibration records shall be maintained and submitted to the enforcing agency upon request.

(3) Well metering requirements may be waived by the enforcing agency if written verification from a groundwater sustainability agency or other regulating agency is provided to the enforcing agency that confirms that the site is subject to equivalent requirements and resulting metering data is available or reported to the enforcing agency consistent with this Article.

(b) Water Level Monitoring.

(1) Water Level Records and Reporting. The owner or user of a well shall record water levels within the well or a dedicated monitoring well at least monthly, and shall report the readings to the enforcing agency annually by February 1 of the following calendar year, except for water wells with cumulative groundwater use of five (5) acre feet or less of water per year.

(c) The Board of Supervisors may establish fees in connection with review and processing of submitted reports by the enforcing agency.

(Ord. No. 6422, § I(Exh. A), 4-18-2023)

Unless the conditions of approval for a discretionary permit require otherwise, the following Water Conservation and Best Management Practices are required on parcels for which a water well permit was submitted after October 4, 2022, and approved, as follows:

(a) Cumulative groundwater extraction. Exceedance of applicable groundwater extraction limits is a violation of this Chapter, and could lead to enforcement of the permit provisions, pursuant to Section 25B-10.

(1) For a well for low water use pursuant to Section 25B-4(e)(6), cumulative groundwater extraction for the parcel shall be limited to two (2) acre feet per year collectively from all wells on the parcel. Permit modification and approval shall be required prior to expansion of groundwater use greater than two (2) acre feet per year.

(2) For a well for existing use pursuant to Section 25B-4(e)(7), cumulative groundwater extraction for the parcel shall be limited to the historic volume of groundwater extracted per year collectively from all wells on the parcel to support legally established land uses that existed as of October 4, 2022. When estimating the amount of historic groundwater use, an average over the three- to five-year period immediately prior shall be used based off land use or best available information.

(3) For a well with net zero groundwater increase pursuant to Section 25B-4(e)(8), groundwater extraction shall be limited to the volume specified in the net zero groundwater increase plan approved for the site.

(b) Level 1 Water Conservation Requirements: the following Level 1 Water Conservation and Best Management Practices are required on parcels for which a water well permit was submitted after, October 4, 2022, excepting public water wells and injection wells, as follows:

(1) Complete a leak and water conservation audit of indoor and outdoor water systems;

(2) Showerheads within all existing habitable spaces on the project parcel shall meet current water efficiency standards defined in the 2019 CA Green Code or most current version, or be retrofit with aerators or flow regulators and have flow rates of 1.8 gallons per minute or less;

(3) Faucets within all existing habitable spaces on the project parcel shall meet current water efficiency standards defined in the 2019 CA Green Code or most current version, or be retrofit with aerators or other flow regulators and have flow rates of 1.8 gallons per minute or less for kitchen faucets and 1.2 gallons per minute or less for lavatory faucets;

(4) New landscapes shall comply with the water efficient landscape regulations contained in Sonoma County Code Section 7D3 Water Efficient Landscape;

(5) For development after October 4, 2022, irrigated grass lawns are prohibited, unless compliant with Sonoma County Code Section 7D3 Water Efficient Landscape;

(6) For existing development prior to October 4, 2022, irrigated grass lawns shall be no greater than 2500 square feet, unless compliant with Sonoma County Code Section 7D3 Water Efficient Landscape;

(7) Downspouts shall be disconnected and roof rainwater routed to disposal locations that maximize infiltration and minimize erosion, unless determined to (1) pose a risk to onsite structures or geologic hazards, or (2) be infeasible due to other site constraints; and

(8) Compliance with applicable water conservation requirements adopted by a Groundwater Sustainability Agency, as applicable to the project site, that are consistent with or more protective than the requirements of this Chapter.

(c) Level 2 Water Conservation Requirements: The following Level 2 Water Conservation and Best Management Practices are required on parcels for which an application was submitted after October 4, 2022 for a well for existing use pursuant to Section 25B-4(e)(7), or for a well with net zero groundwater increase pursuant to Section 25B-4(e)(8):

(1) All water closets within all existing habitable spaces on the project parcel shall meet current water efficiency standards defined in the 2019 CA Green Code or most current version, or have an efficiency of 1.6 gallons per flush or less;

(2) All urinals within all existing habitable spaces on the project parcel shall meet current water efficiency standards defined in the 2019 CA Green Code or most current version, or have an efficiency of 0.125 gallons per flush or less;

(3) All commercial, industrial, and institutional sites shall submit and implement a water conservation plan that details best management practices to reduce groundwater use to the maximum extent feasible; and

(4) All agricultural sites that use greater than two (2) acre feet per year shall:

(i) Submit and implement agricultural water conservation practices plan that includes irrigation design, scheduling, and maintenance, soil moisture monitoring or plant stress monitoring, and other agricultural water conservation best management practices. Enrollment in an agricultural practices monitoring and certification program, approved by the Director, shall fulfill this requirement.

(ii) Submit and implement a frost protection plan. Enrollment in a frost water demand management program, approved by the State Water Resources Control Board, Director, or Sonoma County Agricultural Commissioner shall fulfill this requirement. Sites that do not use water for frost protection are exempt from this requirement.

(iii) Vineyards and orchard irrigation. Vineyards and orchards shall limit growing season groundwater use to the existing use prior to, October 4, 2022, supported by metered data or a site specific irrigation demand analysis; if no data or analysis is provided then a limit of 0.6 acre-feet per acre per year or less shall apply. When calculating the amount of existing growing season groundwater use, an average over the three- to five-year period immediately prior shall be used.

(Ord. No. 6422, § I(Exh. A), 4-18-2023)

(a) Figure 25B-14a.

[Figure]

(Ord. No. 6422, § I(Exh. A), 4-18-2023)