Shelby County Roadgrade Dam 1-81-40, located in Iowa, is a local government-owned structure designed by the USDA NRCS and regulated by the Iowa DNR.
Wind
Humidity
Completed in 1958, this earth dam stands at a height of 26 feet and spans a length of 1300 feet, providing storage capacity for water supply and recreation purposes. With a normal storage capacity of 250 acre-feet and a drainage area of 2.8 square miles, the dam serves the Tr-Mill Creek watershed in Shelby County.
Despite its low hazard potential and moderate risk assessment, this dam has not been rated for its condition assessment. The spillway type is uncontrolled, with no outlet gates or associated structures. The dam has a surface area of 21 acres and a maximum storage capacity of 539 acre-feet. While the dam has not undergone recent inspections or been assessed for emergency action preparedness, its role in water management for the local community underscores the importance of continued monitoring and maintenance to ensure its reliability and safety in the face of changing climate conditions.
Year Completed |
1958 |
Dam Length |
1300 |
Dam Height |
26 |
River Or Stream |
TR-MILL CREEK |
Primary Dam Type |
Earth |
Surface Area |
21 |
Drainage Area |
2.8 |
Nid Storage |
539 |
Hazard Potential |
Low |
Foundations |
Soil |
Nid Height |
26 |
Boyer River At Logan
|
417cfs |
Soldier River At Pisgah
|
112cfs |
Little Sioux River Near Turin
|
1040cfs |
Maple River At Mapleton
|
323cfs |
Monona-Harrison Ditch Near Turin
|
158cfs |
West Nishnabotna River At Hancock
|
154cfs |