Pumping Stations and Drainage Structures 1

WBV-16.2 – Bayou Segnette Complex, Jefferson Parish, Louisiana, for the New Orleans District, Corps of Engineers

The Bayou Segnette Complex involved enclosing Company Canal to allow it to serve as a safe harbor during storm events and provide a new line of hurricane protection to 100 year storm levels.  The project consisted of constructing levees, T-Walls, a 400 cfs drainage pumping station, and a 56’ wide sector gate to provide protection against the 1% storm surge.  A 60-foot wide navigation channel extends upstream and downstream of the sector gate.  A T-wall also extends from the sector gate to an earthen levee.  The earthen levee extends to the flood wall north of Lapalco Boulevard.

Construction of the new sector gate structure included installation of support piles and sheet piles; placement of structural concrete; construction of guide walls, watercraft protection, and dolphins; and installation of sector gates and mechanical equipment.  Construction of the new pumping station included installation of support piles and sheet piles, placement of structural concrete, construction of the pump station building, installation of the pumps and mechanical equipment, construction of a trash rack with mechanical cleaning equipment, and associated architectural work.

One of the major challenges of this project consisted of construction in a low-lying area with portions of the site being situated in a navigable waterway.  These conditions resulted in frequent flooding.  Because of the potential for flooding, most of the critical features of work were constructed inside of temporary retaining structures.  Another challenge consisted of the number of contractors working in a restricted space which required constant coordination and open lines of communication.

Major Features of Construction Included:

  • Clearing and grubbing of the project site, which is in a low-lying, swampy area;
  • Design, installation and removal of three major TRSs for the sector gate, pumping station and T-wall/channel closure structures;
  • Placement of approximately 7,800 CY of reinforced concrete;
  • Approximately 75,000 CY of channel excavation by dredging, including one navigable channel for the sector gate;
  • Construction of nine T-wall monoliths;
  • Approximately 58,000 CY of compacted fill for construction of levee embankment;
  • Design and implementation of emergency gap closure and temporary flood protection plans to replace existing protection removed for construction access tie-ins with new protection;