Louisiana Coastal Protection and Restoration Authority

Calcasieu Ship Channel salinity control project

Duration:
Ongoing

The Challenge

The Calcasieu Ship Channel connects the Gulf of Mexico to the Port of Lake Charles, but it also serves as a conduit for salt water to move into Calcasieu Lake and the surrounding wetlands. The introduction of salt water into these primarily fresh wetlands, that include key National Wildlife Refuge habitat, contributes the loss of wetlands that not only provide recreational opportunities, but also protection from coastal flooding. The challenge facing the region and the state is in finding the best way to stop the inflow of salt water into the system while also maintaining an open passage for navigation along the vital Calcasieu Ship Channel which is responsible more than 30 percent of the jobs in the Lake Charles metropolitan area. 

The Approach

The Institute collected data on salinity and other water quality parameters, and did screening-level modeling to evaluate a wide array of salinity control alternatives developed by the Louisiana Coastal Protection and Restoration Authority. After narrowing down the alternative solutions, the Institute’s role was expanded to perform detailed modeling as part of the engineering, design, and permitting phase of the project. Specifically, the Institute developed and applied a suite of models (MIKE Flood, Delft3D, and the Integrated Compartment Model) to help evaluate the remaining salinity control alternatives.

In the design and engineering phase, the Institute undertook an additional phase of data collection and modeling to get a better picture of the pathways of sediment movement through the system, and to develop a sediment budget in order to get a better understanding of how the proposed project might impact dredging operations in the channel. Another aspect of the data collection and modeling will be used to evaluate water drainage and channel navigability throughout a large storm event.

Data collection in support of the design and engineering phase modeling includes lower ship channel bathymetry, Calcasieu Lake sediment cores (to investigate geotechnical properties and sedimentation rates), as well as boat-based and fixed station hydrological measurements (salinity, temperature, and water level), cross-sectional channel flow, and turbidity for estimation of suspended sediment transport.