Mid-Breton Sediment Diversion

Historically, sediment-rich water overflowed the banks of the Mississippi River and moved through coastal Louisiana, nourishing healthy wetlands. However, the construction of levees along the lower Mississippi River has since prevented those flows. Resulting subsidence, combined with several other factors, results in the loss of a football field of land every 100 minutes. The purpose of the Mid-Breton Sediment Diversion project is to again divert the sediment-laden Mississippi River waters back into the Breton Sound Basin.

A gated diversion system is being designed to divert approximately 50,000 cubic feet of water per second, or 5 percent of the Mississippi River during high flows, through existing levees to the Breton Sound. A suite of 3D computer models and a physical model are being used to help determine the location of the inlet and the configuration of the corridor through which the diversion system will operate. Water quality modeling is being performed using Delft3D and hydraulic and sediment transport analyses are being performed using HEC-RAS, MIKE21, FLOW-3D, Delft3D and ADCIRC.

This project is considered key to reversing coastal land loss. Upon completion, an estimated 67,500 acres of marsh will be restored, sequestering around 24,000 tons of carbon each year.