waterway construction

  The Tennessee-Tombigbee Waterway is the largest water resource project ever built in the United States. It is one of the engineering marvels of the world. The major features of the waterway are 10 locks and dams; a 175-foot deep canal connecting the Tennessee River with the Tombigbee Tenn-Tom WaterwayRiver watershed; and, 234 miles of navigation channels. The federal project was designed and constructed by the U.S. Army Corps of Engineers with annual appropriations from the U.S. Congress. Corps employees   performed most all of the engineering and design work and served as the construction manager for the project. Actual construction was accomplished by private contractors selected to build specific components of the project by competitive bids.

  The Mobile District of the Corps was responsible for the southern 195 miles of the waterway, including 9 of the locks and dams. The remaining 29 miles of the project, including Whitten Lock and Dam, the third highest single lift lock east of the Rockies; and, the massive excavation of the so-called Divide Cut, were wert the responsibility of the Corps' Nashville District.

A Massive Earth Moving Project  The Tenn-Tom is the largest earth moving project in history, requiring the excavation of nearly 310 million cubic yards of soil or the equivalent of more than 100-million dump truck  loads. By comparison, the French dug about 105 million cubic yards in building the Suez Canal and a total of 210 million cubic yards of earth were removed from the Panama Canal.

  Construction began in December 1972 with the building of the Howell Heflin Lock and Dam (formerly Gainesville LD) at the southern end of the waterway. A total of 2.2 million cubic yards of concrete and 33,000 tons of reinforcing steel were used in building the 10 locks. The 110 x 600-foot lock chambers hold an average of about 20 million gallons of water, an amount equivalent to that used each day by a city Lock Installationwith a population of about 60,000. A series  of culverts, resembling large tuning forks as shown here, were constructed in the bottom of each lock to allow the lock chambers to empty or fill in about 20 minutes without any turbulence or whirl pools that might cause safety concerns for boats being locked. The safe raising or lowering of the water levels inside the chamber is most important since some of the commercial tows consist of shipments of as much as 6 million gallons of fuel as well as chemicals. Waterways are the safest mode for moving these kinds of commodities.

  The Tennessee-Tombigbee was the first large water resource project constructed in accordance with the provisions of the National Environmental Policy Act of 1969 (NEPA) [Click your browser BACK button to return to this document]. Major design changes were made to better accommodate environmental quality as mandated by NEPA. An example of these changes in the project's design is the nearly 50-mile levee shown above on the left side of the first photo. The levee was added to prevent the destruction of prime wildlife habitat along the upper reaches of the Tombigbee River caused by permanent flooding from the impoudments of 5 locks.

  One of the most challenging features of the waterway to design and construct was the so-called Divide Cut, a 27-mile canal that connects the Tenn-Tom with Pickwick Lake on the Tennessee River.

  To build this navigation canal, which is 280 feet wide and 12 feet deep, required the removal of 150 million cubic yards of earth. Seven private contractors, using conventional equipment, completed this awesome task in less than 8 years.

  The deepest cut was 175 feet with an average excavation of 50 feet along the entire reach of the canal. The two photos shown here offer a before and after look at this construction challenge.

Part of the Tenn - Tom Cut
A Bridge on the Waterway

  The dirt removed from the Cut was placed in nearby valleys. These spoil disposal areas were carefully contoured and landscaped in a manner that precluded one of the most potentially serious environmental problems associated with the waterway construction.

   Construction of the waterway also involved the relocation or replacement of 8 railroad bridges and 14 highway Bridge under Constructionbridges. The States of Alabama and Mississippi were responsible for building the highway bridges, which cost $155 million. The  accompanying photo is of a railroad relocation in the Divide Cut, showing a massive earth fill that had to be built to provide uninterrupted rail service and later was removed when the bridge was completed.

  Special programs were implemented during construction to help increase regional economic benefits. The waterway region was one of the most economically depressed sections of the nation at that time. Moreover, many of these counties are rural and some have majority populations of minorities. Many of the waterway residents had no working experience or skills in heavy construction crafts.

  Some unprecedented measures were undertaken to help insure that the lives of these economically deprived people were improved by the waterway's construction. For example, a local hiring preference clause was included in each construction contract that required the contractor to attempt to hire as much of his work force as possible from within a 50-mile radius of the waterway.

Workers Support Constuction of the Waterway  A very progressive minority hiring program was instituted that included employment goals for each construction craft. A separate program with specific goals was also established for female workers. To meet these ambitious objectives, intensive job training efforts were implemented, including a unique worker-trainee program that required the close cooperation of the affected   trade unions, the contractors and the Corps of Engineers.

  These social programs were very successful. Construction of the waterway required 25 million man-hours of labor. About 85 percent of these workers came from the waterway corridor. At the end of construction, the work force included 33 percent minorities and nearly 5 percent female workers. Also, nearly $450 million of work was subcontracted to minority firms.

  Because of these successes, the Carter Administration selected the Tenn-Tom as a national demonstration project of how to maximize local economic impacts of a large public works project built in a rural area.

  These programs not only accomplished socio-economic objectives, but they also precluded the typical "boon and bust" conditions generally experienced when large projects are built in sparsely populated areas that do not have the infrastructure or services to support a large influx of workers.

Open for Traffic  Construction was completed on December 12,1984 exactly 12 years after it began. The total cost was $l.992 billion, including non-federal costs. The waterway will have a physical life of 100 years or more and an assumed economic life of 50 years. This investment will return economic benefits to many generations to come.