Washoe County, in alignment with the Federal Emergency Management Agency (FEMA) requirements and obligations, has updated flood hazard information using the latest data and mapping technology in the Swan Lake area of Washoe County. The remapping effort focuses on updating the FEMA Flood Insurance Rate Maps (FIRM) that identify the 1 percent risk (100-year) flood risks around Swan Lake. This is one of several areas in Washoe County to be analyzed and remapped.
This work replaces the previous flood maps that were based on outdated studies and older mapping techniques. The work also recognizes that no updates had been made 
to FEMA’s maps since 2009. As a result of many factors, including weather pattern changes and improved analytical techniques, flood risks change over time. New digital mapping techniques provide better topographically information on where flood water may encroach or where flood hazards have increased. In response, the remapping project for Swan Lake provides updated, accurate flood risk information for this closed hydro basin.
The National Flood Insurance Reform Act of 1994 requires FEMA, and therefore local jurisdictions, to update flood maps on a five-year basis when new and more accurate information becomes available. While it is not common for flood maps to be updated every five years, in fact over 75 percent of the flood maps across the United States are older than five years, Washoe County is currently updating several flood maps in the County. The County is committed to providing updated and accurate information to residents so that they can make informed decisions about their flood risks, flood insurance needs and property safety.
“Residents who don’t know their flood risk might be inclined to skip obtaining the proper insurance, and this could have detrimental effects on their homes if and when a flood happens,” Washoe County Engineer Dwayne Smith said. “Just as those who live in the wildland-urban interface are more likely to experience wildfires, and those living in seismically active zones are more likely to experience earthquakes, those living in floodplains have a greater risk of experiencing flooding, and they need to be aware of that risk.”
There are approximately 95 residential properties that are added to FEMA’s current 1 percent (100-year) floodplain boundary for Swan Lake. They now join the approximately 97 residential properties that were already within FEMA’s floodplain boundary, for a total of approximately 192 residential properties. There are approximately 14 U.S. Government, Washoe County, TMWA, and other commercial properties that are also now within the floodplain boundary. Attached is a map that shows both the existing and impacted properties. With this new information, Washoe County and FEMA encourage those affected residents to review their flood insurance options and determine what is best for their property.
Washoe County recognizes this change can be a significant concern to many of the County residents who reside around Swan Lake. To help bring this information to those affected residents, County staff sent letters to residents affected by the change in floodplain and will hold a community meeting January 29, 2025, to answer questions and learn about flood risk from county officials and flood management experts. Washoe County recognizes our responsibility to share this new information with the residents and commercial property owners and are available to answer questions regarding the process. Visit www.lvfloodplain.com to learn more.
