Howard A. Hanson Dam
Washington — King County — GREEN
Location
| State | Washington |
| County | King |
| River | GREEN |
| Coordinates | 47.27821, -121.78655 |
Physical Characteristics
| NID Height | 235 ft |
| Dam Height | — |
| Dam Length | 500 ft |
| NID Storage | 136,700 acre-ft |
| Max Storage | 136,700 acre-ft |
| Surface Area | 20,000 acres |
Safety Classification
| Hazard Potential | High |
| Condition Assessment | Not Available |
| EAP Status | Yes |
| Last Inspection | November 19, 2025 |
| Inspection Frequency | 5 |
Dam Information
| Year Completed | 1962 |
| Primary Purpose | Flood Risk Reduction |
| Dam Type | Rockfill |
| Owner Type | Federal |
| Owner | USACE - Seattle District |
Location Map
About This Dam Record
Dam safety data is maintained by the Army Corps of Engineers National Inventory of Dams (NID). High-hazard dams are those where failure could cause loss of life or major property damage downstream.