Mississippi River Lock And Dam 6
Mississippi River Lock And Dam 6 is a concrete dam located in Winona County, Wisconsin, built in 1936. It carries a Significant hazard potential classification.
About Mississippi River Lock And Dam 6
The primary purpose of Mississippi River Lock And Dam 6 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 - St. Paul District (federal). It impounds the Mississippi River near Trempealeau.
The dam stands 40 feet tall and stretches 4,865 feet across, creates a reservoir covering 8,870 acres, has a maximum storage capacity of 180,000 acre-feet, and collects water from a drainage area of 60,030 square miles. Completed in 1936, 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 05/23/2024.
At 40 feet, this dam is taller than 87% of dams nationwide.
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Location
| State | Wisconsin |
| County | Winona |
| Nearest City | Trempealeau |
| River/Stream | Mississippi River |
| Coordinates | 43.99869, -91.43843 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 40 ft |
| Dam Height | 17 ft |
| Dam Length | 4,865 ft |
| Year Completed | 1936 (90 years old) |
Storage & Hydraulics
| NID Storage | 180,000 acre-ft |
| Max Storage | 180,000 acre-ft |
| Normal Storage | 41,000 acre-ft |
| Surface Area | 8,870 acres |
| Drainage Area | 60,030 sq mi |
| Max Discharge | 268,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Navigation |
| Owner | USACE - St. Paul District |
| Owner Type | Federal |
| Hazard Classification | Significant |
| Condition Assessment | Not Available |
| Last Inspection | 05/23/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | WI00802 |
| Federal ID | WI00802 |
| More Info | State Dam Safety Program |