Three alternatives were developed to resolve neighborhood flooding caused by off-site drainage and inadequate public and private stormwater infrastructure. PACE provided hydrologic/hydraulic analysis, preliminary drawings, and cost estimates for each alternative and led a public meeting. The preferred alternative was a gravity pipe bypass that required right-of-way approval from multiple agencies and private property owners. PACE prepared SEPA, JARPA, permit, and construction documentation.


Client Name

City of SeaTac


SeaTac, WA


  • Solution Alternatives
  • Hydrologic/Hydraulic Analysis
  • Stormwater Gravity Pipe Bypass Design
  • SEPA & JARPA Permitting
  • Right-of-Way Approval
  • Construction Documentation