Faced with a public loss of confidence in New Orleans’ remaining defenses, the U.S. Army Corps of Engineers (USACE) awarded the contract for the Inner Harbor Navigation Canal – Lake Borgne Surge Barrier to Shaw Environmental and Infrastructure, Inc. As a subconsultant to the prime contractor, Tetra Tech led the design of the $1.1 billion surge barrier project as part of a joint venture with Ben C. Gerwick, Inc.

The surge barrier is the largest civil works design-build project in USACE history, consisting of 3 gates that allow vessel passage through the 10,000-foot-long, 26-foot-high concrete barrier wall and a complete floodwall closure of the Mississippi River Gulf Outlet. Tetra Tech developed preliminary and detailed designs of an innovative 150-foot-wide buoyant sector gate at the Gulf Intracoastal Waterway, and the structural monoliths, towers and foundations of a 56-foot-wide vertical lift gate with vehicular bridge at Bayou Bienvenue.

In addition to design project management services, Tetra Tech provided engineering services during construction. In May 2011, despite the complicated technical challenges created by the project’s aggressive timeline, 100-year-level storm risk reduction was attained.

Due in part to Tetra Tech’s award-winning effort, New Orleans is now more protected than ever. Construction of the surge barrier shifted the primary risk reduction system from the city center, eliminating the need for raising approximately 30 miles of existing levees and floodwalls. The realization of this extraordinary project has been both a precedent-setting feat of engineering and a tremendous source of pride for Louisiana.