Numerical Modeling of Hydrodynamics and Waves for Corpus Christi Ship Channel, Texas

The US Army Corps of Engineers, Coastal Modeling System was applied to evaluate changes in hydrodynamics and wave conditions from a proposed deepening/widening configuration of Corpus Christi Ship Channel (CCSC). Model calibration and validation were based on recent field data collected in May and June 2018. The model grid and bathymetry were based on previous modeling studies and updated with channel surveys conducted in September 2017 and May 2018.

The existing CCSC is a 45-ft deep draft channel, relative to Mean Lower Low Water, extends from deep water in the Gulf of Mexico through a jettied entrance and across Corpus Christi Bay, approximately 34 miles inland. The present CCSC Improvement Project is congressionally authorized to deepen and widen the existing ship channel to a depth of 54 ft and width of 530 ft, and to extend the La Quinta Ship Channel 1.4 miles at a depth of 43 ft to the Port’s La Quinta Multi-Purpose Facility.

The modeling effort includes hydrodynamic and wave conditions for typical seasonal wind waves affecting the study area and during Hurricane Harvey in August 2017. Two representative months of April and December in 2017 were selected for modeling southeasterly and northerly wind conditions, respectively. The period of 20 July to 20 August in 2017 was selected for the southerly wind condition. Hurricane Harvey was modelled for the period of August 21-31, 2017. A 50-year sea level rise (SLR) condition was simulated for the period of 20 July to 31 August including southerly wind scenario and Hurricane Harvey.

Model current velocities along CCSC in Corpus Christi Bay are generally weak, less than 0.3 m/sec, as influenced more by bay circulation and occasional storm events. Stronger currents occur with the channel improvement project, up to 0.1 to 0.2 m/sec stronger along CCSC than without the project, especially under high wind and wave conditions in April and December 2017, and during Harvey.

Model results show much larger waves outside Aransas Pass in the Gulf than in Corpus Christi Bay. The difference of maximum wave heights along CCSC with and without the channel improvement project is 0.1 m (with greater wave height in the existing configuration) based on the scenario with Harvey. The effect with the project to wave heights and water levels in the bay with the 50-year SLR is minimal. More model result and comparison with and without the project will be provided in the full paper.