Terrebonne to Bayou Vista Transmission Upgrade
Owner: Entergy Louisiana
Lead Design Firm/General Contractor: Burns & McDonnell
The project team performed a transmission upgrade through one of Louisiana’s most fragile and ecologically diverse ecosystems.
Entergy Louisiana and CLECO Power LLC collaborated on the project to replace aging power infrastructure with all new facilities built to withstand hurricanes and other extreme weather events. The $65-million upgrade spanned 36 miles through Louisiana’s bayou system, from Entergy’s Terrebonne substation to CLECO’s Bayou Vista substation.
To gain regulatory approval, the project team had to develop plans to assure minimal disturbance to vegetation and wildlife in the tightly woven ecosystem. The contractor’s first task was to produce a detailed environmental assessment, which formed the foundation of the plan. Regulators required zero long-term environmental impact on wildlife or wetlands in the entire footprint of the project.
Access was the project’s main challenge. In uninhabited areas, the project team relied on helicopter lifts to set poles. Crews encountered eagle nests that required work to stop, and helicopter flights had to be rerouted to avoid disturbing nests.
Careful planning regarding local bridges was also necessary, as many bridges carry weight restrictions that prevent the transport of heavy equipment. The project team had to airlift or tow this equipment through the marsh.
Bayous and swamps presented harsh work zone conditions and are home to alligators and snakes. But the primary risk was the operation of specialty equipment required for the swamp conditions. The project team took steps to provide extra training and address safety practices.