CLARENCE CANNON DAM

Monroe City, Missouri

This project for the U.S. Army Corps of Engineers was to construct the main dam, spillway, power plant substructure, and intake for the Clarence Cannon Reservoir near Monroe City, Missouri.

The dam is named after Clarence Cannon, chairman of the House Appropriations Committee and longtime member of the U.S. House of Representatives.

The dam impounds the upper Salt River about 63 miles upstream from its confluence with the Mississippi River. Approximately 165 miles of the river and its tributaries were inundated, creating the 18,000-acre Mark Twain Lake. 450,000 cubic yards of concrete were used in the construction of a 138-foot-tall, 1,940-foot-long dam.

The Clarence Cannon Dam contains a hydroelectric power plant capable of producing up to 58,000 kilowatts of power, or enough to supply a town of 20,000 people. Shafts connect a generator to a turbine that is powered by falling water hitting turbine blades. As much as 5,400,000 gallons of water pass through the turbines each minute when the plant is operating at capacity.