Mississippi River Locks and Dam 1 is a concrete dam located in Hennepin County, Minnesota, built in 1917. It carries a Significant hazard potential classification.
Dam profile
NID height · 56 ft56 ft tall and 742 ft long, taller than 94% of U.S. dams with a recorded height. Height is drawn to scale against a ten-story building, about 100 ft; the profile is a generic concrete gravity section and the water level is illustrative.
About Mississippi River Locks and Dam 1
The primary purpose of Mississippi River Locks and Dam 1 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; Ford Motor Company (federal). It impounds the Mississippi near St. Paul.
The dam stands 56 feet tall and stretches 742 feet across, creates a reservoir covering 900 acres, has a maximum storage capacity of 9,300 acre-feet, and collects water from a drainage area of 19,500 square miles. Completed in 1917, 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. An emergency action plan is in place for this dam. The most recent inspection on record was 07/13/2021.
At 56 feet, this dam is taller than 94% 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 | Hennepin |
| Nearest City | St. Paul |
| River/Stream | Mississippi |
| Coordinates | 44.91537, -93.20179 |
Physical Characteristics
| Dam Type | Concrete |
| NID Height | 56 ft |
| Dam Height | 49 ft |
| Dam Length | 742 ft |
| Year Completed | 1917 (109 years old) |
Storage & Hydraulics
| NID Storage | 9,300 acre-ft |
| Max Storage | 9,300 acre-ft |
| Normal Storage | 5,400 acre-ft |
| Surface Area | 900 acres |
| Drainage Area | 19,500 sq mi |
| Max Discharge | 742 cfs |
| Spillway Type | Uncontrolled |
Ownership & Safety
| Purpose | Navigation |
| Owner | USACE - St. Paul District; Ford Motor Company |
| Owner Type | Federal |
| Hazard Classification | Significant |
| Condition Assessment | Not assessed |
| Last Inspection | 07/13/2021 |
| Emergency Action Plan | Yes |
Identifiers
| NID ID | MN00593 |
| Federal ID | MN00593 |
| More Info | State Dam Safety Program |