Kennewick No 1 Aerated Wastewater Lagoon is an earth dam located in Benton County, Washington, built in 1975. It carries a High hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 24 ft24 ft tall. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Kennewick No 1 Aerated Wastewater Lagoon
Kennewick No 1 Aerated Wastewater Lagoon is a dam in Benton, Washington. The dam is owned by Kennewick City Public Works (local government). It impounds the Offstream-columbia R. near Kennewick.
The dam stands 24 feet tall, creates a reservoir covering 10 acres, has a maximum storage capacity of 132 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1975, the structure is well into its service life at over 50 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. An emergency action plan is in place for this dam. The most recent inspection on record was 03/23/2016. That was 10 years ago — unusually long for a high-hazard dam, which typically requires more frequent inspections.
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 | Benton |
| Nearest City | Kennewick |
| River/Stream | Offstream-columbia R. |
| Coordinates | 46.20678, -119.09825 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 24 ft |
| Year Completed | 1975 (51 years old) |
Storage & Hydraulics
| NID Storage | 132 acre-ft |
| Max Storage | 132 acre-ft |
| Normal Storage | 114 acre-ft |
| Surface Area | 10 acres |
| Drainage Area | 0 sq mi |
Ownership & Safety
| Purpose | Other |
| Owner | Kennewick City Public Works |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 03/23/2016 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WA01796 |
| Federal ID | WA01796 |
| More Info | State Dam Safety Program |