A new control structure was designed to moderate and control flow from Alligator Bayou and Bayou Manchac. The structure is located adjacent to an existing gated box culvert with headwalls at either end. This existing structure was removed and the new cast-in-place concrete control structure constructed adjacent to it. The control structure is approximately 74ft x 40ft in plan dimension and nearly 22ft tall. It is founded on timber piles and contains three gates on the Bayou Manchac side. The entire structure is within a dike with the top of the structure serving as a roadway surface. The height of the structure was designed to be higher than the surrounding dike to ensure that heavy rain events do not exceed the height of the structure. Each end contains permanent sheet pile wing walls with a concrete cap beam. An emergency generator will be located on the top slab adjacent to the roadway for power to be supplied to instrumentation. Rip rap was designed to protect significant areas around the control structure after grading was complete to restore certain portions of each bayou which has eroded.
Iberville Parish, Louisiana
Design –2017, Construction – Completed in 2018