Mono County introduces mandatory watercraft inspection ordinance to stop invasive golden mussel

Mono County supervisors on March 3 introduced a proposed ordinance that would require inspection and potential decontamination of trailered watercraft before they enter any waters in Mono County, part of a regional effort to prevent establishment of the invasive golden mussel.

Marcela Rose, the county’s outdoor recreation superintendent, told the board that the golden mussel can survive a wider range of water chemistry and temperature than earlier invasive mussels and therefore poses a realistic threat to Eastern Sierra waterways, infrastructure and recreation businesses. Rose said the Eastern Sierra Golden Mussel Collaborative — which includes county staff, the California Department of Fish and Wildlife and neighboring jurisdictions — piloted voluntary inspection and decontamination stations in 2025 and concluded voluntary measures were not sufficient to ensure the compliance needed to prevent infestation.

The ordinance as drafted would apply to trailered watercraft and would authorize an inspection, possible decontamination and a stickering program that shows a vessel was cleared. Initial policy language excludes non‑trailered craft such as kayaks or paddleboards but allows the program to expand if needed. The ordinance outlines enforcement options that would typically begin as infractions and could escalate to misdemeanors for repeated or egregious noncompliance; impoundment is listed as a possible enforcement tool for willful refusal of inspection.

To operate three recommended new inspection and decontamination stations (Bishop, Lee Vining and Bridgeport), staff estimated roughly $75,000 in first‑year costs for staffing and outreach. Rose asked the board to approve $15,000 from county sources to help launch the effort in year one; staff proposed covering half from the county’s Geothermal Fund (recreation) and half via an award from the Fish and Game Fine Fund to a nonprofit operator (Sierra Forever) that would hire station staff.

Supervisors asked about reciprocity with inspection programs in adjacent counties and about coverage for lakes nearer Mammoth Lakes and Convict Lake. Rose said the collaborative intends to establish multiple stations and regional reciprocity so stickers issued in neighboring jurisdictions would be accepted in Mono County. Forest Service representatives and California Department of Fish and Wildlife wardens have told staff they will support enforcement and, where appropriate, issue citations when they observe attempts to evade inspection.

The board voted to introduce the ordinance, read the title and waive further reading; a second reading and final vote are scheduled for next week with an effective date aimed for about April 10 so the rule could be in place before the county’s fishing opener. The item also included a staff commitment to return with a formal grant or application process for the Fish and Game Fine Fund contribution and a follow‑up budgetization for the Geothermal Fund contribution.

Supporters framed the program as prevention that protects drinking water, marina infrastructure and the county’s recreation‑dependent economy. Some supervisors stressed the need for robust public outreach and plenty of inspection locations so visitors can plan stops before reaching more remote lakes.

The board’s introduction of the ordinance does not finalize funding; the requested $15,000 allocation will be brought back in the next business meeting for formal action on the specific funding sources.