Washoe County details South Truckee Meadows floodplain remapping as residents press maintenance and insurance concerns

Dwayne Smith, Washoe County engineer, and Rob Wyler, a county mapping presenter, delivered a detailed update to the Citizens Advisory Board on a multi-year FEMA remapping of the South Truckee Meadows watershed, saying the effort aims to produce more accurate floodplain boundaries and lower exposure for some properties.

"We're working collaboratively with FEMA, local agencies, the Truckee Rivers Flood Management Authority, and Washoe County Emergency Management," Rob Wyler said, explaining that updated topography and modeling have driven recent map updates. He noted the county has completed remapping for Boneyard Flat and Swan Lake in 2025 and is pursuing remapping for Thomas, Whites and Dry creeks downstream.

The presentation summarized the process and timeline: FEMA began the larger remapping effort in 2019; consultants were retained in April 2024; FEMA issued preliminary maps in December 2024; Reno and Washoe County submitted a technical appeal in December 2025 and are waiting for FEMA's response. Wyler said preliminary Washoe County mapping shows fewer structures in the regulatory floodplain within unincorporated areas.

County Engineer Dwayne Smith described what updated maps mean for homeowners and local mitigation. "These FEMA flood maps are tools to help identify areas at greater risk," Smith said, adding that improved models and elevation data have reduced the number of structures captured in some regulatory floodplain designs. He also described mitigation steps the county has taken after major events, including Hazard Mitigation Grant Program (HMGP) buyouts that removed repeatedly flooded structures at Swan Lake and converted them to open space.

Residents pushed back in a lengthy Q&A. Marge Franson and other Hidden Valley residents recounted the July 2024 flash flood that clogged ditches with sediment, damaged yards and driveways, and in some cases left costs for cleanup to homeowners. One resident said muddy debris from that event was not covered by flood insurance because policies typically cover structural water damage rather than soil/mud deposition. Another resident noted historical records of repeated flooding in some areas and asked how much weight staff give to historical accounts versus models.

Smith acknowledged those concerns and emphasized the limits of mitigation: "Flood mitigation is mitigation — it doesn't remove risk," he said, adding that updated maps and hydrology studies are intended to help residents and planners make better decisions and reduce future costs. County staff described ongoing coordination with the City of Reno on shared projects (for example, Toll Road), operation and maintenance responsibilities for retention ponds (HOAs submit maintenance manuals), and code-enforcement mechanisms when private parties fail to maintain drainage easements.

Staff also committed to continued outreach: they said they will hold community meetings, review elevation certificates for at-risk properties, and make technical staff available for follow-up. The engineers noted an important practical benefit: Washoe County’s participation in FEMA’s Community Rating System yielded discounts for some unincorporated residents’ flood insurance.

The presentation closed with next steps: Washoe County will continue technical appeals with FEMA, pursue targeted outreach in Hidden Valley and Sun Valley, and seek funding for capital mitigation projects where appropriate. Residents were encouraged to meet staff one-on-one for technical explanations and to track the county’s appeal to FEMA.