The Board of Supervisors on Aug. 19 authorized county staff to mail weighted, property-owner ballots under Proposition 218 to fund a countywide mosquito and vector-control assessment. Staff said current assessments have not kept pace with rising operational costs and with new invasive-mosquito threats.

What the assessment would do: Vector-control staff described countywide surveillance, laboratory testing for disease-carrying mosquitoes and treatment and outreach capacity that the division provides. Assistant Vector Control Manager Amanda Poulsen told the board that the county identified an operational shortfall and is proposing an assessment of approximately $11.99 per single-family-equivalent parcel in the primary surveillance zone (slightly lower rates apply in a reduced- service zone).

Ballot mechanics and schedule: SCI Consulting Group explained that property owners would receive ballots listing all of their assessed parcels; each mailed ballot is weighted by the parcel's proposed assessment. Ballots returned by Nov. 4 would be tabulated and announced on Nov. 18. Approval requires a simple majority of returned weighted ballots.

Board direction and vote: Supervisors praised staff for proactive planning and authorized staff to proceed with mailing ballots. The board was briefed on the assessment methodology and on the requirement that assessment increases be capped at 3 percent per year (adjusted to CPI, subject to the annual limit).

Outlook: If property-owner ballots supporting the assessment are returned by the required majority threshold, the assessment would appear on property tax bills and fund ongoing county surveillance and response work for mosquitoes and other vectors.