Modeling coastal sediment transport at the mouth of the Colorado River, Texas

This paper describes diagnostic numerical simulations of waves, current, sediment transport, and morphology change at the mouth of the Colorado River, Texas. The simulations were performed with the Inlet Modeling System (IMS) developed by the Coastal Inlets Research Program at the Coastal and Hydraulics Laboratory, U.S. Army Engineer Research and Development Center. The IMS version applied consists of the circulation and sediment transport model M2D coupled with the wave spectral model STWAVE. The study site exhibits complex patterns of sediment transport over a weir jetty and deposition in an impoundment basin. Six alternatives are evaluated by comparison of calculated morphologic change and sediment impoundment coupled with the hydrodynamics over a 1-year simulation interval. Simulations are performed with and without a sediment training structure, different jetty lengths, and different weir lengths and elevations. The alternatives are examined for effectiveness in improving efficiency of the impoundment basin and in reducing sediment shoaling in the entrance channel to decrease dredging frequency.