Lucky Peak Dam
Lucky Peak Dam is a rockfill dam located in Ada County, Idaho, built in 1955. It carries a High hazard potential classification.
About Lucky Peak Dam
The primary purpose of Lucky Peak 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 Usace - Walla Walla District (federal). It impounds the Boise River near Boise.
The dam stands 340 feet tall and stretches 2,340 feet across, creates a reservoir covering 2,820 acres, has a maximum storage capacity of 307,043 acre-feet, and collects water from a drainage area of 2,680 square miles. Completed in 1955, 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. An emergency action plan is in place for this dam. The most recent inspection on record was 10/22/2024.
At 340 feet, this dam is taller than 99% 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 Idaho 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 | Idaho |
| County | Ada |
| Nearest City | Boise |
| River/Stream | Boise River |
| Coordinates | 43.52797, -116.05370 |
Physical Characteristics
| Dam Type | Rockfill |
| NID Height | 340 ft |
| Dam Length | 2,340 ft |
| Year Completed | 1955 (71 years old) |
Storage & Hydraulics
| NID Storage | 307,043 acre-ft |
| Max Storage | 307,043 acre-ft |
| Normal Storage | 293,138 acre-ft |
| Surface Area | 2,820 acres |
| Drainage Area | 2,680 sq mi |
| Max Discharge | 93,300 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | USACE - Walla Walla District |
| Owner Type | Federal |
| Hazard Classification | High |
| Condition Assessment | Not Available |
| Last Inspection | 10/22/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | ID00288 |
| Federal ID | ID00288 |
| More Info | State Dam Safety Program |