Mississippi River Lock And Dam 6 Reservoir Report

Last Updated: December 5, 2025

Mississippi River Lock and Dam 6, also known as Pool 6, is a federal structure located in Trempealeau, Wisconsin, along the Mississippi River.


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Summary

Completed in 1936 by the US Army Corps of Engineers, this concrete dam serves primarily for navigation purposes, with additional benefits for recreation. The dam stands at a height of 17 feet, with a hydraulic height of 26 feet and a structural height of 40 feet, stretching over a length of 4865 feet and holding a volume of 271,700 cubic feet.

With a significant hazard potential, the dam has a controlled spillway type with a width of 1750 feet. It features one lock measuring 600 feet in length and 110 feet in width, facilitating the passage of vessels along the river. Managed by the US Army Corps of Engineers, the dam undergoes regular inspections and has an emergency action plan in place to address flood risks and ensure public safety. The agency works actively to monitor and address any potential issues to maintain the dam's structural integrity and manage water levels effectively.

In response to the varying challenges posed by severe weather events and water inflow, the US Army Corps of Engineers implements risk management measures to mitigate potential flood risks associated with the dam. By engaging with local emergency managers and the public, regularly updating emergency action plans, and prioritizing maintenance activities, the agency strives to ensure the safety and functionality of Mississippi River Lock and Dam 6.

Year Completed

1936

Dam Length

4865

Dam Height

17

River Or Stream

MISSISSIPPI RIVER

Primary Dam Type

Concrete

Surface Area

8870

Length Of Locks

600

Hydraulic Height

26

Drainage Area

60030

Nid Storage

180000

Structural Height

40

Outlet Gates

Roller - 5, Tainter (radial) - 10, Uncontrolled - 0

Hazard Potential

Significant

Foundations

Soil

Nid Height

40
       
Seasonal Comparison

Weather Forecast

Dam Data Reference

Condition Assessment

Satisfactory
No existing or potential dam safety deficiencies are recognized. Acceptable performance is expected under all loading conditions (static, hydrologic, seismic) in accordance with the minimum applicable state or federal regulatory criteria or tolerable risk guidelines.
Fair
No existing dam safety deficiencies are recognized for normal operating conditions. Rare or extreme hydrologic and/or seismic events may result in a dam safety deficiency. Risk may be in the range to take further action. Note: Rare or extreme event is defined by the regulatory agency based on their minimum
Poor A dam safety deficiency is recognized for normal operating conditions which may realistically occur. Remedial action is necessary. POOR may also be used when uncertainties exist as to critical analysis parameters which identify a potential dam safety deficiency. Investigations and studies are necessary.
Unsatisfactory
A dam safety deficiency is recognized that requires immediate or emergency remedial action for problem resolution.
Not Rated
The dam has not been inspected, is not under state or federal jurisdiction, or has been inspected but, for whatever reason, has not been rated.
Not Available
Dams for which the condition assessment is restricted to approved government users.

Hazard Potential Classification

High
Dams assigned the high hazard potential classification are those where failure or mis-operation will probably cause loss of human life.
Significant
Dams assigned the significant hazard potential classification are those dams where failure or mis-operation results in no probable loss of human life but can cause economic loss, environment damage, disruption of lifeline facilities, or impact other concerns. Significant hazard potential classification dams are often located in predominantly rural or agricultural areas but could be in areas with population and significant infrastructure.
Low
Dams assigned the low hazard potential classification are those where failure or mis-operation results in no probable loss of human life and low economic and/or environmental losses. Losses are principally limited to the owner's property.
Undetermined
Dams for which a downstream hazard potential has not been designated or is not provided.
Not Available
Dams for which the downstream hazard potential is restricted to approved government users.