Pierce County seeks public comments on updated Nisqually Watershed flood maps

In partnership with the Department of Homeland Security’s Federal Emergency Management Agency, Pierce County is updating the flood insurance rate maps along the Nisqually River.

These maps are used by FEMA to show where flood insurance is required and by the county to identify where floodplain regulations are applied. The maps also help individuals and communities better understand flood risks so they can make more informed decisions about how to protect themselves from losses and damage.

These new maps are now available on the Pierce County website, https://www.piercecountywa.gov/7396/FEMA-Maps.

The county is asking for help from the public in reviewing these maps for any possible errors and other comments of concerns. The comment period will last 90 days from May 5 to Aug. 3.

These flood insurance rate maps, last updated in 1987, are drawn based on national engineering standards that look at the flow of the river and geometry of the valley.

According to the Pierce County website, following the 1996 Nisqually River Flood, it became clear that the current FEMA maps grossly underestimated the flood risks on the Nisqually River as several homes outside of the mapped floodplain were damaged.

This mapping effort used the latest hydrology and survey information to determine the areas that will be flooded in the 1-percent-annual-chance flood. This is also known as a 100-year flood, the base flood or the special flood hazard areas.