Clarence Cannon Dam Reservoir Report

Last Updated: December 19, 2025

Clarence Cannon Dam, also known as Mark Twain Lake, is a concrete dam located on the Salt River in Ralls, Missouri.


°F

°F

mph

Wind

%

Humidity

Summary

Completed in 1983 by the US Army Corps of Engineers, the dam stands at a height of 138 feet and has a structural height of 188 feet. With a primary purpose of flood risk reduction, the dam also serves various other functions such as fish and wildlife pond, hydroelectric power generation, navigation, recreation, and water supply.

The dam boasts a storage capacity of 1,862,000 acre-feet and covers a surface area of 5,900 acres. It is equipped with a controlled spillway, wide spillway width of 230 feet, and four Tainter (radial) outlet gates. Despite its high hazard potential, the dam is regularly inspected and monitored for any potential risks. The US Army Corps of Engineers actively manages dam-related flood risks by implementing risk management measures, conducting regular maintenance and repairs, and updating the emergency action plan to ensure the safety of the surrounding communities.

Overall, Clarence Cannon Dam serves as a vital infrastructure for flood control and water resource management in the region, showcasing a commitment to safeguarding the environment and public safety through proactive risk management and emergency preparedness efforts.

Year Completed

1983

Dam Length

1940

Dam Height

138

River Or Stream

SALT RIVER

Primary Dam Type

Concrete

Surface Area

5900

Hydraulic Height

133

Drainage Area

2318

Nid Storage

1862000

Structural Height

188

Outlet Gates

Tainter (radial) - 4

Hazard Potential

High

Foundations

Rock, Soil

Nid Height

188
       
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.
View more

Area Campgrounds