Moving into phase 2 of the HNC Lock Complex

The Louisiana Coastal Protection and Restoration Authority (CPRA) and the Terrebonne Levee & Conservation District (TLCD) have announced that the Houma Navigation Canal (HNC) Lock Complex project is moving into Phase 2 construction.

Photo courtesy of CPRA

TLCD awarded the construction contract, valued at more than $300 million, to SeaLevel Construction, Inc., a Louisiana-based company headquartered in Thibodaux.

The HNC Lock Complex is a large-scale hydrologic restoration project that will help limit saltwater intrusion and distribute freshwater within the Terrebonne Basin, allowing for the maintenance of thousands of acres of wetlands, which serve as critical wildlife habitat and nurseries for fisheries.

Once constructed, the HNC Lock Complex will span 110 feet across and stand 800 feet high with gates on either side, directly adjacent to the existing 250-foot-wide Bubba Dove barge floodgate.

The two components will be tied together by a braced flood wall across the channel and work in concert to allow larger ships to pass through the canal. The HNC Lock Complex will also close one of the few remaining gaps of the Morganza to the Gulf hurricane protection system, which uses a mix of levees, floodgates, and locks to protect 150,000 Terrebonne and Lafourche residents from potentially deadly storm surge.

Phase 2 includes construction of Inland and Gulf-side gates as well as the lock chamber to complete the HNC Lock Complex. The Phase 2 portion also includes the completion of the operations area, the control building, and the 175-foot control building access bridge.

This phase also consists of hydraulically dredging approximately 135,000 cubic yards of material from the HNC to reestablish 15 acres of brackish marsh habitat, benefiting the area’s ecosystem and wildlife.