Spook Hill
Spook Hill is an earth dam located in Maricopa County, Arizona, built in 1979. It carries a High hazard potential classification and has a satisfactory condition assessment.
About Spook Hill
The primary purpose of Spook Hill 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 Flood Control District Of Maricopa County (local government). It impounds the Salt River - Tr near Mesa.
The dam stands 27 feet tall and stretches 21,120 feet across, creates a reservoir covering 305 acres, has a maximum storage capacity of 4,250 acre-feet, and collects water from a drainage area of 16 square miles. Completed in 1979, the structure is 47 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 11/13/2024.
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 Arizona 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 | Arizona |
| County | Maricopa |
| Nearest City | Mesa |
| River/Stream | Salt River - Tr |
| Coordinates | 33.47306, -111.68167 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 27 ft |
| Dam Height | 15 ft |
| Dam Length | 21,120 ft |
| Year Completed | 1979 (47 years old) |
Storage & Hydraulics
| NID Storage | 4,250 acre-ft |
| Max Storage | 4,250 acre-ft |
| Surface Area | 305 acres |
| Drainage Area | 16 sq mi |
| Max Discharge | 21,000 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Flood Risk Reduction |
| Owner | FLOOD CONTROL DISTRICT OF MARICOPA COUNTY |
| Owner Type | Local Government |
| Hazard Classification | High |
| Condition Assessment | Satisfactory |
| Last Inspection | 11/13/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | AZ00175 |
| Federal ID | AZ00175 |
| More Info | State Dam Safety Program |