Entergy Ninemile-Barataria Electrical Transmission Line Rebuild
Entergy is proposing to rebuild/replace an existing timber supported 115kV transmission line crossing the Barataria Preserve unit of Jean Lafitte National Historic Park and Preserve (JLNP). The Ninemile-Barataria transmission line provides a critical power source to the electrical transmission system in southeast Louisiana.
The line runs from the Entergy owned Ninemile Point Generation Switch Station in Westwego, LA to Entergy's Barataria Substation, which is located in the southern portion of the Barataria Preserve unit near Crown Point (+/-15 total miles). The line runs approximately eight (8) miles through the preserve within an existing 100' ROW.
The existing line was constructed in 1964 and is nearing the end of its service life. The current condition of the line requires frequent maintenance on rapidly deteriorating timber support structures. In order to respond to these maintenance issues, Entergy crews are currently required to access the preserve and cross sensitive wetlands with heavy equipment multiple times throughout a typical year.
Completion of the proposed project would reduce the need for maintenance within the park. Rebuilding the Ninemile-Barataria line would also result in increased transmission grid reliability and future load serving capabilities. The target in service date for the project is on or before 6/30/2020.
Entergy proposes to rebuild the Ninemile-Barataria 115kV line adjacent to the existing ROW utilizing 230kV standards. This project would replace the existing timber H-frame structures with single pole self-supported steel structures, which are designed to withstand higher wind loads and be more resilient in the coastal environment. These new structures would also eliminate the need for guy wires and reduce the overall footprint of the line and its supports. The overall project can be divided into three (3) primary segments, and only one segment will be evaluated in this EA. The first segment involves rebuilding 3.6 miles of existing line starting at the Ninemile Switchyard and ending at Churchhill Junction, and the second segment consists of 2.1 miles of existing line along Lapalco Blvd. and ending at the protection levee located just south of Lapalco Blvd. The scope of work being evaluated by the National Park Service is as follows:
• Rebuild/replace 9.5 miles of the existing Ninemile-Barataria 115kV line, using 230kV specifications, from the protection levee located just south of Lapalco Blvd to the Barataria Substation, which includes approximately eight (8) miles through the JLNP. A large portion of this line would be constructed immediately adjacent to the existing line to minimize the 115kV outage requirements and also reduce the environmental impacts to the area.
Haigler "Dusty" Pate
Natural Resource Program Manager
504 589-3882 x119