Kachess Dam
Kachess Dam is an earth dam located in Kittitas County, Washington, built in 1912. It carries a High hazard potential classification.
About Kachess Dam
The primary purpose of Kachess Dam is flood risk reduction. The dam is designed to control downstream flooding by temporarily storing excess water during storms and releasing it at a controlled rate. The dam is owned by Bureau Of Reclamation (federal). It impounds the Kachess River near Easton.
The dam stands 115 feet tall and stretches 1,400 feet across, creates a reservoir covering 4,535 acres, has a maximum storage capacity of 239,000 acre-feet, and collects water from a drainage area of 63 square miles. Completed in 1912, the structure is over a century old.
This dam carries a high hazard potential classification, which means that a failure or uncontrolled release of water would likely cause loss of human life. This classification reflects the consequences of failure, not the likelihood — it indicates that people live or work in the area downstream. An emergency action plan is in place for this dam. The most recent inspection on record was 09/02/2022.
At 115 feet, this dam is taller than 98% of all dams in the United States.
Living Downstream
If you live or work downstream of this dam, consider taking these steps: learn your local evacuation routes, check whether your county emergency management office has a dam failure inundation map, and sign up for local emergency alerts. The Washington dam safety program can provide more specific information about emergency planning for this structure.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Washington |
| County | Kittitas |
| Nearest City | Easton |
| River/Stream | Kachess River |
| Coordinates | 47.26450, -121.20570 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 115 ft |
| Dam Height | 63 ft |
| Dam Length | 1,400 ft |
| Year Completed | 1912 (114 years old) |
Storage & Hydraulics
| NID Storage | 239,000 acre-ft |
| Max Storage | 239,000 acre-ft |
| Normal Storage | 239,000 acre-ft |
| Surface Area | 4,535 acres |
| Drainage Area | 63 sq mi |
| Max Discharge | 4,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | BUREAU OF RECLAMATION |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 09/02/2022 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WA00260 |
| Federal ID | WA00260 |
| More Info | State Dam Safety Program |