Mississippi River Lock And Dam 20 Reservoir Report

Last Updated: December 14, 2025

Mississippi River Lock and Dam 20, also known as Pool 20, is a Federal-owned structure located in Canton, Missouri along the Mississippi River.


°F

°F

mph

Wind

%

Humidity

Summary

Completed in 1936, this concrete gravity dam stands at a structural height of 37 feet and has a length of 2604 feet. It serves the primary purpose of navigation, with a single lock measuring 600 feet in length and 110 feet in width.

Managed by the US Army Corps of Engineers, Mississippi River Lock and Dam 20 plays a crucial role in controlling water levels and facilitating safe navigation along the river. With a hazard potential rated as significant, the dam is regularly inspected and monitored to assess its condition and ensure its structural integrity. In the event of a dam-related emergency, the Corps has emergency action plans in place and collaborates with local agencies to mitigate risks and protect surrounding communities.

As part of its risk management measures, the US Army Corps of Engineers implements ongoing maintenance and repairs to address potential flood risks associated with the dam. By engaging with emergency managers and the public, the Corps aims to raise awareness and preparedness for potential emergencies. With its strategic location and critical role in water resource management, Mississippi River Lock and Dam 20 continues to be a vital asset in safeguarding communities along the Mississippi River.

Year Completed

1936

Dam Length

2604

River Or Stream

MISSISSIPPI RIVER

Primary Dam Type

Concrete

Surface Area

7542

Length Of Locks

600

Hydraulic Height

11

Drainage Area

134300

Nid Storage

58000

Structural Height

37

Outlet Gates

Roller - 3, Tainter (radial) - 40

Hazard Potential

Significant

Foundations

Rock

Nid Height

37
       
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.