The Upper St. Anthony Falls (USAF) Lock and Dam is part of the Inland Waterway Navigation System of the Upper Mississippi River Basin. While the lock was originally authorized for navigation, Section 2010 of the Water Resources Reform and Development Act of 2014 directed the Secretary of the Army to close the Upper St. Anthony Falls lock to navigation traffic. The lock was closed June 10, 2015.
The Water Resources Reform and Development Act of 2014 explicitly states that the project is still authorized to conduct emergency lock operations necessary to mitigate flood damage. The U.S. Army Corps of Engineers installed a tainter gate at the upstream end of the USAF lock chamber. The tainter gate provides redundancy for the upstream miter gates and allows flows to be safely passed through the lock chamber during flood events. Historically, the tainter gate has been operated to pass flood flows six times since 1965. The lock will only be operated to pass flood flows.
Attempts to operate the gate have failed on various occasions, and reliability is a concern. The tainter gate’s electrical control system has not been upgraded for many decades. Because the ram cylinder rooms and operating machinery rooms were constantly wet and the lower parts of the cylinders and hydraulic piping were usually underwater, the system’s hydraulics could not be relied on to function as needed.
The purpose of the project is to replace the existing operating equipment with a system that is reliable, easy to use, and resistant to damage from water infiltration in the galleries. One goal is reduced long-term maintenance because of reduced staffing levels after the USAF navigation closure.
A contract for this rehabilitation work was awarded in September 2017. Work began in May 2018. The contract will be completed in August 2019 with the final testing and programming. Funding for the project has been received.
Congress authorized the Mississippi River 9-foot channel as part of the Rivers and Harbors Act, approved July 3, 1930.
Construction of the locks at Upper and Lower St. Anthony Falls was authorized by the Rivers and Harbors Act of 1937, which approved extension of the 9-foot channel to the Minneapolis upper harbor.
Estimated total project cost $6,000,000