Mississippi River Lock And Dam 12
Mississippi River Lock And Dam 12 is a concrete dam located in Jo Daviess County, Iowa, built in 1938. It carries a Significant hazard potential classification.
About Mississippi River Lock And Dam 12
The primary purpose of Mississippi River Lock And Dam 12 is navigation. The dam maintains water levels sufficient for boat and barge traffic, supporting commercial or recreational navigation on the waterway. The dam is owned by Usace - Rock Island District (federal). It impounds the Mississippi River near Bellevue.
The dam stands 44 feet tall and stretches 8,577 feet across, creates a reservoir covering 10,500 acres, has a maximum storage capacity of 92,000 acre-feet, and collects water from a drainage area of 82,400 square miles. Completed in 1938, 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. An emergency action plan is in place for this dam. The most recent inspection on record was 04/09/2024.
At 44 feet, this dam is taller than 90% of dams nationwide.
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Location
| State | Iowa |
| County | Jo Daviess |
| Nearest City | Bellevue |
| River/Stream | Mississippi River |
| Coordinates | 42.26124, -90.42116 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 44 ft |
| Dam Length | 8,577 ft |
| Year Completed | 1938 (88 years old) |
Storage & Hydraulics
| NID Storage | 92,000 acre-ft |
| Max Storage | 92,000 acre-ft |
| Surface Area | 10,500 acres |
| Drainage Area | 82,400 sq mi |
| Max Discharge | 32,700 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Navigation |
| Owner | USACE - Rock Island District |
| Owner Type | Federal |
| Hazard Classification | Significant |
| Condition Assessment | Not Available |
| Last Inspection | 04/09/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | IA00004 |
| Federal ID | IA00004 |
| More Info | State Dam Safety Program |