Puyallup Floodplain Assessment

Puyallup, Washington

The City of Puyallup contracted ESA to update its stormwater plan and develop an approach to address stormwater quantity and quality issues. We analyzed how basin flooding related to FEMA’s newly-revised regulatory floodplain of the Puyallup River and how regulations should be applied to ensure safety from flooding.

ESA developed a profile of existing and potential future basin conditions to identify flooding issues and evaluate associated potential projects. We performed hydrologic modeling of an undeveloped portion of the City’s UGA. The City was interested in what stormwater management measures would be necessary if this agricultural area was developed. We analyzed changes in runoff patterns for hypothetical build-out scenarios, and determined needed water quality management measures.