Howard A. Hanson Dam
Dam in King County, Washington · Green · forms Howard A Hanson Lake
Height
235 ft
72 m (NID height)
Length
500 ft
152 m
Completed
1962
Howard A Hanson Lake today
1,124.41 ft
7 days ▼ 6.88 ft
Normal storage
26,000 acre-ft
Much above normal for the date
Reservoir level measured Oct 23, 2026, 12:00 PM PDT. Full level page →
Facts
- Purposes
- Flood Risk Reduction; Fish and Wildlife Pond; Water Supply
- Dam type
- Rockfill
- Structural height
- 235 ft
- Owner
- USACE - Seattle District (Federal)
- Maximum storage
- 136,700 acre-ft
- Surface area
- 20,000 acres
- Hydraulic height
- 220 ft
- Drainage area
- 221 sq mi
- Spillway
- Controlled, 90 ft wide
- Army Corps district
- Seattle District
- NID ID
- WA00298
Facts from the U.S. Army Corps of Engineers National Inventory of Dams, record updated Jul 13, 2026. Search NID ID WA00298 at nid.sec.usace.army.mil. Project website.