Maquoketa Milldam is a gravity dam located in Jackson County, Iowa, built in 1923. It carries a Significant hazard potential classification and has a satisfactory condition assessment.
Dam profile
NID height · 26 ft26 ft tall and 700 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 concrete gravity section and the water level is illustrative.
About Maquoketa Milldam
The primary purpose of Maquoketa Milldam is hydroelectric. The dam generates hydroelectric power by channeling water through turbines, converting the energy of flowing water into electricity. The dam is owned by Renewable World Energies (public utility). It impounds the Maquoketa River near Maquoketa.
The dam stands 26 feet tall and stretches 700 feet across, creates a reservoir covering 340 acres, has a maximum storage capacity of 4,419 acre-feet, and collects water from a drainage area of 953 square miles. Completed in 1923, the structure is over a century 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 satisfactory, indicating no existing or potential dam safety deficiencies are recognized. The most recent inspection on record was 09/17/2021.
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Location
| State | Iowa |
| County | Jackson |
| Nearest City | Maquoketa |
| River/Stream | Maquoketa River |
| Coordinates | 42.07020, -90.69790 |
Physical Characteristics
| Dam Type | Gravity |
| NID Height | 26 ft |
| Dam Height | 26 ft |
| Dam Length | 700 ft |
| Year Completed | 1923 (103 years old) |
Storage & Hydraulics
| NID Storage | 4,419 acre-ft |
| Max Storage | 4,419 acre-ft |
| Normal Storage | 4,419 acre-ft |
| Surface Area | 340 acres |
| Drainage Area | 953 sq mi |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Hydroelectric |
| Owner | Renewable World Energies |
| Owner Type | Public Utility |
| Hazard Classification | Significant |
| Condition Assessment | Satisfactory |
| Last Inspection | 09/17/2021 |
| Emergency Action Plan | Not Required |
Identifiers
| NID ID | IA01302 |
| Federal ID | IA01302 |
| More Info | State Dam Safety Program |