Morganza to the Gulf of Mexico Project

Project Information

Official Project Name
Morganza to the Gulf of Mexico Project

Location
The MTG project is in coastal Louisiana approximately 60 miles southwest of New Orleans and includes portions of Terrebonne and Lafourche parishes. The updated plan described in the 2013 Final Post Authorization Change (PAC) Report and the 2021 Engineering Documentation Report (EDR) is bounded by US Hwy 90 near the town of Gibson to the west and LA Hwy 1 near Lockport to the east. Project Purpose & Features The authorized Morganza to the Gulf (MTG) project is a hurricane and storm damage risk reduction (HSDRR) project involving a 98-mile alignment of earthen levees, floodgates, environmental water control structures, road/railroad gates, and fronting protection for existing pump stations. This system is being designed to reduce the risk of damage related to flooding for the 1% Annual Exceedance Probability (AEP) in Terrebonne and Lafourche Parishes where a deterioration of coastal march has led to an increased risk of inundation. This system will reduce the risk of damage related to flooding to approximately 52,000 structures and a population of 200,000 in an area of intense concentration of energy infrastructure near the confluence of two nationally significant navigation corridors in the Mississippi River and the Gulf Intracoastal WaterWay (GIWW).

Project Purpose & Features
The authorized Morganza to the Gulf (MTG) project is a hurricane and storm damage risk reduction (HSDRR) project involving a 98-mile alignment of earthen levees, floodgates, environmental water control structures, road/railroad gates, and fronting protection for existing pump stations. This system is being designed to reduce the risk of damage related to flooding for the 1% Annual Exceedance Probability (AEP) in Terrebonne and Lafourche Parishes where a deterioration of coastal march has led to an increased risk of inundation.
This system will reduce the risk of damage related to flooding to approximately 52,000 structures and a population of 200,000 in an area of intense concentration of energy infrastructure near the confluence of two nationally significant navigation corridors in the Mississippi River and the Gulf Intracoastal WaterWay (GIWW). A major project feature is a lock complex on the Houma Navigation Canal (HNC) consisting of a lock and an adjacent sector gate.

-A major project feature is a lock complex on the Houma Navigation Canal (HNC) consisting of a lock and anadjacent sector gate. The project’s structural features are integrated into the levee alignment in a way that would provide flood protection, drainage, environmental benefits, and navigational passage. The plan includes mitigation efforts for direct environmental impacts 

MTG consists of:

•approximately 98-miles of earthen levee,

•22 floodgates on navigable waterways,

•23 environmental water control structures

•a lock complex consisting of a lock in the Houma Navigation Canal measuring 110-ft wide by 800-ft long, an adjoining floodgate measuring 250 feet wide, and a dam closure.

Project Status
The project was authorized for construction in WRDA 2007, based on 2002 and 2003 reports of the Chief of Engineers, prior to development and implementation of post-Katrina design criteria. Incorporating post-Katrina design criteria into the Morganza project had driven project costs more than 20% higher than the cost authorized in WRDA 2007, thereby exceeding the Section 902 Limit and triggering the need for reauthorization. As a result, a PAC Report was completed, and a Chief of Engineers’ Report was signed on 8 July 2013 to seek reauthorization of the project. The project was reauthorized in Water Resources Reform and Development Act (WRRDA) of 2014 to provide 100-year level of risk reduction. Since re-authorization, the project team has progressed the design implementing site adaptive criteria and work that has been completed on the alignment that updated the cost to $6.5B ($10.2B fully funded through the life of the project) as documented in the EDR approved on 15 December 2021. A Project Partnership Agreement  (PPA) was signed on 28 December 2021 that limits the federal cost share to $3.2B ($4.9B fully funded). 

MTG received New Start construction funding in Fiscal Year 2021 and is currently completing a site preparation and preload contract for future replacement of Humble Canal Floodgate. In addition $378M was received for design and construction of Reach A (portion), Lockport to Larose Reach (portion), Minors Canal Floodgate, GIWW West Floodgate, GIWW East Floodgate, Minors Canal Floodgate and Humble Canal Floodgate. Community Funds received in Fiscal Year 2022 and 2023 will be used for designs for levee lifts and associated construction for Reach F, Reach J-2, Reach L, Reach K, Shell Canal Floodgate and Bayou Terrebonne Floodgate. 
Authority
Water Resources Reform and Development Act of 2014