Afton Reservoir Dam
Afton Reservoir Dam is an earth dam located in Union County, Iowa, built in 1936. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
About Afton Reservoir Dam
The primary purpose of Afton Reservoir Dam is water supply. The dam stores water for municipal, industrial, or agricultural use, helping ensure a reliable supply for the surrounding area. The dam is owned by City Of Afton (local government). It impounds the Tr-twelve Mile Creek near Westerville.
The dam stands 51 feet tall and stretches 800 feet across, creates a reservoir covering 15 acres, has a maximum storage capacity of 470 acre-feet, and collects water from a drainage area of 0 square miles. Completed in 1936, the structure is well-established, with more than 75 years of service.
This dam has a significant hazard potential classification, meaning that a failure could cause significant economic damage — flooding roads, bridges, or property downstream — but is not expected to result in loss of life. Its condition is rated satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 07/27/2021.
At 51 feet, this dam is taller than 93% of dams nationwide.
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Location
| State | Iowa |
| County | Union |
| Nearest City | Westerville |
| River/Stream | Tr-twelve Mile Creek |
| Coordinates | 41.03460, -94.21120 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 51 ft |
| Dam Height | 51 ft |
| Dam Length | 800 ft |
| Year Completed | 1936 (90 years old) |
Storage & Hydraulics
| NID Storage | 470 acre-ft |
| Max Storage | 470 acre-ft |
| Normal Storage | 300 acre-ft |
| Surface Area | 15 acres |
| Drainage Area | 0 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Water Supply |
| Owner | City of Afton |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 07/27/2021 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | IA01378 |
| Federal ID | IA01378 |
| More Info | State Dam Safety Program |