Brazos Santiago Inlet, Texas, shoaling study

The Brazos Santiago Inlet (BSI), located at the southern end of Laguna Madre, is a key part of the federal deep-draft Brownsville Ship Channel extending from the Gulf of Mexico to the Port of Brownsville, TX. As part of the Monitoring Completed Navigation Projects program, the focus of this study was to understand the shoaling process in the BSI and to suggest sand management alternatives to reduce inlet maintenance dredging costs. Hydrodynamics and sediment transport were examined for the BSI region to understand the channel shoaling within the jetty entrance. Field data collection and numerical modeling using the Coastal Modeling System were performed to gain insight into the complex circulation, wave action, and sediment deposition patterns. Structural changes to the system as well as dredging modifications are presented as potential alternative solutions to reduce inlet shoaling. Results show the potential benefits of an in-channel sediment trap and alterations to the structure of the jetty. However, benefits to dredging costs are not considered and must be weighed against other issues such as environmental concerns.