Numerical Modeling of Trinity River Shoaling below Wallisville, Texas

• Main Authors: Letter, Jr, Joseph V, Brown, Gary L, McAdory, Robert, Pratt, Thad C
• Format: Report
• Language: English
• Subjects: DREDGING; FLOW; Hydrology, Limnology and Potamology; MATHEMATICAL MODELS; ORCO(OLD RIVER CUT OFF CHANNEL); RIVERS; SEDIMENT TRANSPORT; SHALLOW WATER; SHOALING

The Trinity River below the navigation lock and salinity control structure at Wallisville, TX, has experienced significant shoaling in recent years. The location of the shoal is immediately downstream of the confluence with the Old River Cut Off channel (ORCO), which has been enlarging and progressively carrying a greater fraction of the discharge at the expense of the Trinity River. The reduction in flow in the Trinity River below the ORCO has resulted in reduced sediment transport capacity which created the shoaling problem. This report presents the results of a numerical model study to evaluate alternatives for potential mitigation of the shoaling problem. The alternatives include dredging the shoal and placing the material into the ORCO, damming the ORCO, and creating partial closure of the ORCO. The model results illustrate the basic problem of an elongated navigation channel with numerous distributary pathways for water and sediment within a deltaic system. The routing of all flow down the Trinity River will result in erosion of the current shoal, but shoaling will then occur below the next bayou that extracts flow from the river. DISCLAIMER: The original document contains color images.