Shelby County Roadgrade Dam 1-81-40 is an earth dam located in Shelby County, Iowa, built in 1958. It carries a Low hazard potential classification.
Dam profile
NID height · 26 ft26 ft tall and 1,300 ft long, taller than 55% of U.S. dams with a recorded height. Height is drawn to scale against a two-story house, about 25 ft; the profile is a generic embankment section and the water level is illustrative.
About Shelby County Roadgrade Dam 1-81-40
Shelby County Roadgrade Dam 1-81-40 is a dam in Shelby, Iowa. The dam is owned by Shelby County Board of Supervisors (local government). It impounds the Tr-mill Creek near Manteno.
The dam stands 26 feet tall and stretches 1,300 feet across, creates a reservoir covering 21 acres, has a maximum storage capacity of 539 acre-feet, and collects water from a drainage area of 2 square miles. Completed in 1958, the structure is well into its service life at over 50 years old.
This dam has a low hazard potential classification, meaning that failure would cause minimal damage, limited primarily to the dam owner's property, with no expected loss of life.
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Location
| State | Iowa |
| County | Shelby |
| Nearest City | Manteno |
| River/Stream | Tr-mill Creek |
| Coordinates | 41.85730, -95.45970 |
Physical Characteristics
| Dam Type | Earth |
| NID Height | 26 ft |
| Dam Height | 26 ft |
| Dam Length | 1,300 ft |
| Year Completed | 1958 (68 years old) |
Storage & Hydraulics
| NID Storage | 539 acre-ft |
| Max Storage | 539 acre-ft |
| Normal Storage | 250 acre-ft |
| Surface Area | 21 acres |
| Drainage Area | 2 sq mi |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Other |
| Owner | Shelby County Board of Supervisors |
| Owner Type | Local Government |
| Hazard Classification | Low |
| Condition Assessment | Not assessed |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | IA00990 |
| Federal ID | IA00990 |
| More Info | State Dam Safety Program |