Nevada County Mining Hazard Assessment Requirements

The Nevada County Board of Supervisors approved an updated Safety Element on Tuesday requiring developers to assess mining hazards before construction begins in unincorporated areas.

The policy addresses legacy mining sites across the county for the first time, requiring developers to evaluate risks from old mines, including chemicals used in past operations.

"The intent of adding these policies is to make sure we are addressing possible safety concerns for legacy mines," said Steve Geiger, principal planner for the county.

Board Chair Lisa Swarthout and Supervisor Heidi Hall supported the change, saying assessments will help property buyers and developers understand risks on their land.

The Safety Element, a chapter of the county's General Plan, guides decisions on public safety, emergency preparedness and hazard mitigation. The update incorporates findings from the 2024 Evacuation Study and includes information on extreme heat, flooding, dam failure, earthquakes, hazardous materials, severe weather, power outages and wildfire.

County staff developed the update with local fire agencies, emergency services, state agencies and community partners. The Safety Element takes effect immediately and applies to all new development proposals in unincorporated Nevada County.