Most waterway navigation projects are more than 75 years old and have suffered from a persistent lack of reinvestment and environmental stresses associated with extreme weather events that magnify the system’s vulnerability.

Many of the nearly 200 infrastructure projects have reached their design life of 50 years, and choke points are adversely affecting more and more commercial users. The upper Mississippi’s Lock & Dam 26 and the Ohio River’s Lock & Dam 52 are examples.

The National Waterways Foundation (NWF), in cooperation with the Maritime Administration (MARAD), released a study -- “The Impacts of Unscheduled Lock Outages”-- examining the economic impacts of unscheduled lock outages and highlighting the economic benefits associated with reliable inland waterway navigation.

“This groundbreaking study reveals, for the first time, the broad range of economic and societal impacts of unscheduled lock outages. Real-world examples occurred during the September 2017 outages at Locks & Dams 52 and 53 in Illinois and at the Inner Harbor Navigation Canal Lock in October 2017 in Louisiana,” NWF chairman Daniel Mecklenborg said.

“The study underscores that if the inland waterways were unavailable to transport the nation’s freight, the average number of trucks on rural highways would increase and result in significant impacts on safety, highway maintenance cost and fuel consumption. Increased rail transportation safety impacts may occur at rail crossings, especially in urban areas, and in increased fuel consumption,” MARAD executive director Joel Szabat said.

The study was conducted by the Center for Transportation Research at the University of Tennessee and the Vanderbilt Engineering Center for Transportation & Operational Resiliency at Vanderbilt University. Four geographically different locks were studied on the inland waterway system: Markland Locks & Dam (Ohio River near Cincinnati, Ohio), which opened in 1959; Calcasieu Lock (Gulf Intracoastal Waterway in Louisiana), which opened in 1950; LaGrange Lock & Dam (southern-most of the navigation structures on the Illinois River), which opened in 1939, and Lock & Dam 25 (Mississippi River north of St. Louis, Mo.), which opened in 1939. These four locks support traffic on every segment of the Mississippi River system.

If an unscheduled and extended outage were to occur at any of the four locks analyzed in the report, the impact would reach across all of the states served by the system and cause billions of dollars in economic harm to shippers, the commerce that depends on those shippers and the communities that rely on this substantial business activity.

Specifically, if an unscheduled closure of the Markland Locks & Dam were to occur, the shipper supply chain cost burden expected is estimated to exceed $1.3 billion annually. An unscheduled outage that carriers and shippers would have no opportunity to prepare for at Markland would require the availability and use of 40,000 additional rail carloads and 60,000 additional truckloads to transport the current cargo transiting the lock.

The shipper supply chain cost burden of an unscheduled closure of the Calcasieu Lock is estimated to exceed $1.1 billion annually. An unscheduled lock outage at Calcasieu would require the availability and use of 10,000 additional railcars and several-hundred locomotives to transport the current cargo transiting the lock.

The shipper supply chain cost burden for a closure at LaGrange and/or Lock & Dam 25 is estimated to exceed $1.5 billion at either lock annually. Unscheduled outages at LaGrange and/or Lock & Dam 25 would severely stress the nation’s railroad system to transport the current cargo transiting the locks. Trucking to alternative waterway locations would mean an additional 500,000 loaded truck trips per year and an additional 150 million truck-miles in affected states.

These navigation projects span a broad range of both geographies and economic purposes and, in some cases, provide freight mobility that may not be easily replaced by other transport modes.

Lock outage duration for this study is based on a one-year closure that triggers long-term changes by shippers and carriers.

While every state that originates or terminates traffic supported by the four locks benefits from the availability of inland navigation, the results reflect the waterway system’s extraordinary commercial value to 18 states, especially Louisiana, Texas and Illinois, the report found.