Tapps Lake Backflow Prevention Structure
Tapps Lake Backflow Prevention Structure is a gravity dam located in Pierce County, Washington, built in 2007. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Tapps Lake Backflow Prevention Structure
The primary purpose of Tapps Lake Backflow Prevention Structure is recreation. The dam creates a reservoir used for recreational activities such as fishing, boating, and swimming. The dam is owned by Cascade Water Alliance (public utility).
The dam stands 22 feet tall, creates a reservoir covering 2,570 acres, and has a maximum storage capacity of 46,655 acre-feet. Completed in 2007, the structure is relatively new.
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 07/20/2017. That was 8 years ago, which is on the longer end for a high-hazard structure.
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 | Pierce |
| Nearest City | Bonney Lake |
| Coordinates | 47.19657, -122.13974 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 22 ft |
| Year Completed | 2007 (19 years old) |
Storage & Hydraulics
| NID Storage | 55,500 acre-ft |
| Max Storage | 46,655 acre-ft |
| Normal Storage | 55,500 acre-ft |
| Surface Area | 2,570 acres |
| Max Discharge | 1,000 cfs |
Ownership & Safety
| Purpose | Recreation |
| Owner | Cascade Water Alliance |
| Owner Type | Public Utility |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 07/20/2017 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WA00703 |
| Federal ID | WA00703 |
| More Info | State Dam Safety Program |