Mill Picayune Watershed Site M-8
Mill Picayune Watershed Site M-8 is an earth dam located in Shelby County, Iowa, built in 1963. It carries a Significant hazard potential classification and has a fair condition assessment.
About Mill Picayune Watershed Site M-8
The primary purpose of Mill Picayune Watershed Site M-8 is fire protection, stock, or small fish pond. The dam maintains a small impoundment used for fire suppression, livestock watering, or as a fish pond. The dam is owned by Shelby County Board Of Supervisors (local government). It impounds the Mill Creek near Manteno.
The dam stands 46 feet tall and stretches 1,365 feet across, creates a reservoir covering 30 acres, has a maximum storage capacity of 2,333 acre-feet, and collects water from a drainage area of 18 square miles. Completed in 1963, the structure is well into its service life at over 50 years old.
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 fair — the dam has minor deficiencies that are being addressed or do not pose an immediate safety threat. The most recent inspection on record was 09/04/2024.
At 46 feet, this dam is taller than 91% of dams nationwide.
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Location
| State | Iowa |
| County | Shelby |
| Nearest City | Manteno |
| River/Stream | Mill Creek |
| Coordinates | 41.84060, -95.50700 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 46 ft |
| Dam Height | 46 ft |
| Dam Length | 1,365 ft |
| Year Completed | 1963 (63 years old) |
Storage & Hydraulics
| NID Storage | 2,333 acre-ft |
| Max Storage | 2,333 acre-ft |
| Normal Storage | 319 acre-ft |
| Surface Area | 30 acres |
| Drainage Area | 18 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Fire Protection, Stock, Or Small Fish Pond |
| Owner | Shelby County Board of Supervisors |
| Owner Type | Local Government |
| Hazard Classification | Significant |
| Condition Assessment | Fair |
| Last Inspection | 09/04/2024 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | IA00999 |
| Federal ID | IA00999 |
| More Info | State Dam Safety Program |