Hemenway Valley Flood Control Dam
Hemenway Valley Flood Control Dam is an earth dam located in Clark County, Nevada, built in 1994. It carries a High hazard potential classification and has a fair condition assessment.
About Hemenway Valley Flood Control Dam
The primary purpose of Hemenway Valley Flood Control 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 City Of Boulder (local government). It impounds the Hemenway Wash near Henderson.
The dam stands 32 feet tall and stretches 825 feet across, creates a reservoir covering 3 acres, has a maximum storage capacity of 21 acre-feet, and collects water from a drainage area of 1 square miles. Completed in 1994, the structure is 32 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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. An emergency action plan is in place for this dam. The most recent inspection on record was 02/27/2024.
At 32 feet, this dam is taller than 76% of dams nationwide.
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 Nevada 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 | Nevada |
| County | Clark |
| Nearest City | Henderson |
| River/Stream | Hemenway Wash |
| Coordinates | 35.99333, -114.82806 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 32 ft |
| Dam Height | 10 ft |
| Dam Length | 825 ft |
| Year Completed | 1994 (32 years old) |
Storage & Hydraulics
| NID Storage | 21 acre-ft |
| Max Storage | 21 acre-ft |
| Surface Area | 3 acres |
| Drainage Area | 1 sq mi |
| Max Discharge | 2,340 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | CITY OF BOULDER |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Fair |
| Last Inspection | 02/27/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | NV10161 |
| Federal ID | NV10161 |
| More Info | State Dam Safety Program |