Louisiana Trustees Release Final Restoration Plan for Restoration of Terrebonne HNC Island

The Louisiana TIG released the Final Restoration Plan for Phase 2 of the Terrebonne Houma Navigation Canal Island restoration project.

The Deepwater Horizon Louisiana Trustee Implementation Group has released the Final Restoration Plan approving the Terrebonne HNC Island Restoration project to restore birds injured by the Deepwater Horizon oil spill.  

The plan, Final Phase 2 Restoration Plan and Environmental Assessment #7.1: Terrebonne HNC Island Restoration Project (PDF, 96 pages), is a continuation of Restoration Plan/Environmental Assessment #7: Wetlands, Coastal, and Nearshore Habitats, and Birds. That plan selected the Terrebonne HNC Island Restoration Project for engineering and design (Phase 1) funding under the Birds Restoration Type. This Final Phase 2 Plan evaluated a reasonable range of design alternatives and selects alternative 7A as the preferred design for construction.   

The project will restore and conserve bird nesting and foraging habitat and create, restore, and enhance barrier and coastal islands and headlands by increasing the acreage of the island from 27.6 acres up to approximately 45 acres of shrub nesting, ground nesting, and marsh habitat. An existing, degraded perimeter rock dike will be restored, and breakwaters may be constructed on the northeast side of the island to provide further protection as well as calm water for loafing birds. Habitat restoration will be accomplished by raising the elevation of HNC Island using dredged material from a borrow area near Cat Island Pass.  

The estimated cost for implementing design alternative 7A is $34 million. The costs of construction, oversight, operation, maintenance, and monitoring costs are included in this estimate.  

The Louisiana Trustees will leverage funding from the settlement of another unauthorized oil discharge, one made in 2006 by the CITGO Petroleum Corporation’s (CITGO) Lake Charles Manufacturing Complex located in Calcasieu Parish, Louisiana. That spill discharged waste oil, oily wastewater, and sludge into the Martais Waterway and ultimately into the Calcasieu River. The oil also affected adjacent marshes and the Calcasieu River’s upstream and downstream receiving waters, including Prien Lake, Moss Lake, Calcasieu Lake, and the Gulf Intracoastal Waterway. 

The Calcasieu River Trustees will partner with the Louisiana TIG to partially fund construction of the Terrebonne HNC Island project to compensate for injuries to birds resulting from the CITGO spill. They will contribute $1.65 million from the CITGO settlement to the Terrebonne HNC Island project to increase the quantity and quality of coastal island nesting habitat for species injured by the CITGO spill, such as brown pelicans, wading birds (herons and egrets) and laughing gulls.  

The Draft Phase 2 Restoration Plan and Environmental Assessment #7.1: Terrebonne HNC Island Restoration Project (PDF, 80 pages) was released on August 25, 2022, for a 30-day public comment period. A public webinar conducted on September 8 included a presentation of the draft plan and included an opportunity for public comment. The Trustees did not receive any public comments on the draft plan.  

Final Plan Materials 


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