Impacts of Industrial Fresh Water Withdrawals on Calcaiseu Lake Hydrodynamics and Salinity Concentration

In the authors’ previous study, vegetation information was utilized into a hydrodynamic model to predict the flooding coverage and damage to the wetlands in a major water system in southwest Louisiana, the Calcasieu Lake water system. In this study, the target area is extended, ranging from the city of Lake Charles as the north end to the Gulf of Mexico as the south end, including Lake Charles, Calcasieu Lake, Prien Lake, Gulf Intracoastal Waterway (GIWW) and the entire Calcasieu Ship Channel. Measured vegetation data is utilized in the vegetated areas and appropriate friction values are assigned to different types of non-vegetated areas. Salinity is important to aquatic life. It can impact agricultural production, water quality and streams, biodiversity and infrastructure. In this study, both hydrodynamic and salinity transport simulations are conducted. Measurement data from NOAA and USGS are used as boundary conditions. Simulation results were compared with NOAA and USGS data in several other locations. Lake Charles is one of the largest petrochemical industry centers in the country. Numerous plants use tremendous amount of fresh surface water in the area. Recent expansions of several companies increase the fresh water withdraws from the system significantly. One of the purposes of the study is to investigate the effects of increased water withdraw on the hydrodynamics and salinity in the system. The industrial water withdrawals could be from the Calcasieu River in the north of Lake Charles, which is the north boundary of the simulation domain. Cases of different reduced flow rates at Lake Charles were tested, and the effects on hydrodynamics and salinity concentrations and distributions were analyzed. The results can be used as a guideline for industrial and city development in the areas.