Major dredging project to prepare area for the HNC Lock Complex

Louisiana state officials and Coastal Protection and Restoration Authority (CPRA) yesterday broke ground on the Houma Navigation Canal (HNC) Lock Complex and announced the completion of the Grand Bayou Floodgate, two critical components of the Morganza to the Gulf Hurricane Protection System.

With the completion of the 147-foot Grand Bayou Floodgate, the Morganza to the Gulf system now has a continuous levee segment stretching 47 miles from Grand Bayou in Lafourche Parish to upper Bayou Dularge in Terrebonne Parish to prevent floodwaters from impacting the region.

The newly completed floodgate was named in honor of the late Louisiana Rep. Reggie Bagala, who passed away from complications due to COVID-19 in April 2020.

The Morganza to the Gulf system will benefit approximately 1,900 square miles in Terrebonne and Lafourche parishes through flood control, salinity control, and ecosystem restoration.

Phase 1 of the HNC Lock Complex project will dredge over 1 million cubic yards of material to prepare the area for the lock complex and create 178 acres of marsh in six areas north of the complex along the navigation channel. Phase 1 is anticipated to be complete in the fall of 2022.

The HNC Lock will allow a longer window of opportunity for navigation activities when the adjacent Bubba Dove Floodgate is closed to protect communities from storm surge or high water events. During gate closures, the lock will allow vessels to travel in either direction on the HNC, enabling officials to close the floodgate earlier and keep it closed longer, benefiting the area’s ecosystem suffering from saltwater intrusion.

The HNC Lock Complex is a joint effort of CPRA and the Terrebonne Levee and Conservation District. A tentative bid date for construction of Phase 2 of the lock structure, which will include an 800-foot lock chamber with 110-foot-wide sector gates, is anticipated in spring 2022.

Engineering, design, and construction for Phases 1 and 2 of the HNC Lock Complex are funded with money resulting from the damages of the Deepwater Horizon oil spill, allocated through the Resources and Ecosystems Sustainability, Tourist Opportunities, and Revived Economies of the Gulf Coast States Act (RESTORE Act).

Photo: CPRA