Coulee City Wastewater Lagoon
Coulee City Wastewater Lagoon is an earth dam located in Grant County, Washington, built in 1997. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Coulee City Wastewater Lagoon
Coulee City Wastewater Lagoon is a dam in Grant, Washington. The dam is owned by Coulee City Town Public Works Dept (local government). It impounds the Grand Coulee - Offstream near Coulee City.
The dam stands 7 feet tall and stretches 5,220 feet across, creates a reservoir covering 30 acres, and has a maximum storage capacity of 172 acre-feet. Completed in 1997, the structure is 29 years 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. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. Notably, no emergency action plan is currently on file for this high-hazard dam. The most recent inspection on record was 05/11/2022.
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 | Grant |
| Nearest City | Coulee City |
| River/Stream | Grand Coulee - Offstream |
| Coordinates | 47.60151, -119.28597 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 7 ft |
| Dam Length | 5,220 ft |
| Year Completed | 1997 (29 years old) |
Storage & Hydraulics
| NID Storage | 172 acre-ft |
| Max Storage | 172 acre-ft |
| Normal Storage | 111 acre-ft |
| Surface Area | 30 acres |
Ownership & Safety
| Purpose | Other |
| Owner | Coulee City Town Public Works Dept |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 05/11/2022 |
| Emergency Action Plan | No |
Identifiers
| NID ID | WA00658 |
| Federal ID | WA00658 |
| More Info | State Dam Safety Program |