High Risk 🌊 Major Dam / Flood Control  ·  Washington

Green River Levee System WA

CRITICAL INFRASTRUCTURE RISK PROFILE  ·  WASHINGTON

8 / 10
Risk Score
Facility Type
🌊 Major Dam / Flood Control
Primary Risk Radius
10
mile zone
Secondary Risk Radius
50
mile zone

// Risk Intelligence

Risk Score8 / 10   High
Facility Type🌊 Major Dam / Flood Control
Operator / BranchKing County Flood Control District
Host CountyKing County WA
Nearest CityPepperell MA
Primary Risk Radius10 miles
Secondary Risk Radius50 miles

// Strategic Significance

The Green River levee system protects the Green River valley south of Seattle including Auburn Kent Renton and Tukwila from catastrophic flooding. Howard Hanson Dam upstream was found to have a seepage problem in 2009 requiring emergency repairs and reducing its flood storage capacity. During the 2009 emergency King County issued evacuation orders for 70,000 valley residents as officials feared the dam could fail.

// Civilian Impact Assessment

The Green River valley with 100,000 residents and massive industrial warehousing supporting Seattle area commerce faces serious flood risk. Howard Hanson Dam seepage problems reduced protection. Boeing facilities and major distribution centers are in the flood zone.

// Evacuation & Shelter Guidance

SR-167, SR-18, Auburn Way. King County Emergency Management maintains detailed Green River valley evacuation plans with 70,000 resident warning protocols.

// Counties Within Risk Zone

// Cities Within Risk Zone