MRGO and Inner Harbor Navigation Canal Surge Barrier Project Gets Under Way
A surge barrier, similar to a floodwall but much larger, is being built near the confluence of the Gulf Intracoastal Waterway (GIWW) and the Mississippi River Gulf Outlet (MRGO), generally running north-south from a point just east of Michoud Canal on the north bank of the GIWW and just south of the existing Bayou Bienvenue flood control structure. Navigation gates will be constructed where the barrier crosses the GIWW and Bayou Bienvenue to reduce the risk of storm surge coming from Lake Borgne and/or the Gulf of Mexico. Another navigation gate is planned for the Seabrook vicinity where the Inner Harbor Navigation Canal (IHNC) meets Lake Pontchartrain, to block storm surge from entering the IHNC from there. The Army Corps of Engineers is committed to providing a 100-year level of risk reduction for southeast Louisiana in 2011 through its Hurricane and Storm Damage Risk Reduction System (HSDRRS). The HSDRRS seeks to upgrade existing flood protection features (such as levees and floodwalls) and introduce new features authorized by Congress and deemed necessary to complete the system. The Inner Harbor Navigation Canal (IHNC) surge barrier is a new feature, authorized by Congress in 2006, that will reduce the risk of storm damage to some of the region’s most vulnerable areas – New Orleans East, metro New Orleans, the 9th Ward, and St. Bernard Parish.
Attendees and media on a Corps of Engineers observation barge in the MRGO watch as pile driving for the surge barrier progresses.
Lieutenant General Robert Van Antwerp, Chief of Engineers, Army Corps of Engineers, confirms the Corps’ commitment to the area while IHNC Resident Engineer LTC Vic Zillmer and IHNC Senior Project Manager Maj. Jeremy Chapman watch
Assistant Secretary of the Army (Civil Works), the Honorable John Paul Woodley, Jr. opened the ceremony following the National Anthem.
A drawing of the MRGO barrier.
Coastal Protection & Restoration Authority Chairman Garret Graves represented the State of Louisiana, a partner in all hurricane and storm damage risk reduction projects.
A construction kick-off ceremony was held on the Mississippi River Gulf Outlet on Thursday, December 11. Defense of the Greater New Orleans’ most vulnerable area from storm surge began Thursday, December 11 with the groundbreaking of the Inner Harbor Navigation Canal (IHNC) Lake Borgne Surge Barrier Project.
Approximately 200 local residents, political leaders, and Corps officials celebrated the start of the largest design-build, civil-works project in the Corps’ history aboard a Corps inspection barge anchored near the middle of the two-mile-long project site.
“To achieve these project goals, the Corps, the state, our local partners and the local communities must all work together. It’s all about teamwork,” said the Corps’ Task Force Hope Director, Karen Durham-Aguilera.
The IHNC Surge Barrier Project is a significant piece of the Hurricane and Storm Damage Risk Reduction System (HSDRRS) because it will block the powerful Gulf of Mexico storm surge from entering the Gulf Intracoastal Waterway (GIWW).
When completed in 2011, the $700 million surge barrier will extend from the Michoud Canal floodwall along the GIWW to the Mississippi River Gulf Outlet (MRGO) levee just south of the Bayou Bienvenue control structure. It will reduce the hurricane and storm surge risk faced by the people in the surrounding communities of St. Bernard, New Orleans East, Ninth Ward, and Gentilly to a one percent chance in any given year.
“When we see this surge barrier, we will know that it is a stance we’ve taken for the betterment of the people in New Orleans,” said Army Corps of Engineers Commander, Lt. Gen. Robert Van Antwerp. Six features make up the IHNC Lake Borgne Surge Barrier Project. The GIWW features include the GIWW north floodwall, the GIWW gates, and the GIWW to Bayou Bienvenue floodwall. The Bayou Bienvenue features include the Bayou Bienvenue gate, and the Bayou Bienvenue to MRGO south floodwall. The final feature of the barrier is the MGRO south floodwall.
The Corps awarded the IHNC Lake Borgne Surge Barrier contract to Shaw Environmental & Infrastructure of New Orleans, Louisiana in April 2008. Shaw has completed nearly 50 percent of the design for the project.
The Corps and Shaw estimate that construction will require approximately 57,000 tons of steel, 2,600 closure piles and 1,300 concrete vertical piles approximately 5½ feet in diameter and 144 feet long, each weighing 92 tons.
Additionally, 660 steel batter piles 36 inches in diameter will provide support for the structure The initial barrier, standing over 14 feet high will provide advance measures.
Later, 300 deck sections, 17 feet long, 12 feet wide and six feet high, each weighing 96 tons will sit on top of the main surge barrier. The deck sections will bring the height of the barrier to 20 feet above water. Crenels and merlons added to the decks, a feature giving the barrier the appearance similar to the open and closed spaces on battlement fortifications in castles, will bring the total height of the structure to 24 and 26 feet.
The Corps expects to complete the IHNC Lake Borgne Surge Barrier in 2011, with advance measures put into place during hurricane season in 2009.