Mississippi River Lock and Dam 7 is a concrete dam located in La Crosse County, Minnesota, built in 1937. It carries a Significant hazard potential classification.
Dam profile
NID height · 41 ft41 ft tall and 10,860 ft long, taller than 87% 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 Mississippi River Lock and Dam 7
The primary purpose of Mississippi River Lock and Dam 7 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 near La Crescent.
The dam stands 41 feet tall and stretches 10,860 feet across, creates a reservoir covering 13,440 acres, has a maximum storage capacity of 105,000 acre-feet, and collects water from a drainage area of 62,340 square miles. Completed in 1937, 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 05/30/2024.
At 41 feet, this dam is taller than 87% of dams nationwide.
Search for dams near your address to see all dams in your area with hazard classifications and safety data.
Location
| State | Minnesota |
| County | La Crosse |
| Nearest City | La Crescent |
| River/Stream | Mississippi |
| Coordinates | 43.86681, -91.30745 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 41 ft |
| Dam Height | 16 ft |
| Dam Length | 10,860 ft |
| Year Completed | 1937 (89 years old) |
Storage & Hydraulics
| NID Storage | 105,000 acre-ft |
| Max Storage | 105,000 acre-ft |
| Normal Storage | 48,000 acre-ft |
| Surface Area | 13,440 acres |
| Drainage Area | 62,340 sq mi |
| Max Discharge | 273,000 cfs |
| Spillway Type | Controlled |
Ownership & Safety
| Purpose | Navigation |
| Owner | USACE - St. Paul District |
| Owner Type | Federal |
| Hazard Classification | Significant |
| Condition Assessment | Not assessed |
| Last Inspection | 05/30/2024 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MN00587 |
| Federal ID | MN00587 |
| More Info | State Dam Safety Program |