Modeling the Hydraulic Effectiveness of a Proposed Storm Surge Barrier System for the Houston Ship Channel during Hurricane Events

Abstract

The Houston Ship Channel (HSC) in Houston, Texas, is home to the second-busiest port in the United States in terms of overall tonnage and contains one of the largest petrochemical complexes in the world. As such, undisturbed operations of the HSC are vital to ensuring the economic prosperity of local, state, and national interests. History has proved that coastal infrastructure systems and operations at the HSC are easily disrupted by severe rainfall and storm surge conditions induced by hurricanes (e.g., Hurricane Ike in 2008). A coupled riverine-coastal hydraulic model was developed to quantitatively evaluate flood and storm surge vulnerability for the HSC and Galveston Bay, Texas, as an initial testbed for simulating extreme flooding scenarios. A numerical investigation was made on the combined interactions of upland runoff and downstream surge occurrences. This includes an evaluation on the hydraulic effectiveness of a proposed surge gate at reducing surge inundation levels inland and near HSC infrastructure for a simulated Hurricane Ike event, and associated variations of Hurricane Ike surge characteristics. Sensitivities in peak stage, upland flows, and relative timing separations between rainfall hydrographs and storm surges were also explored. Results show that a proposed surge gate system can be an effective way to reduce surge inundation levels and the floodplain extent within the HSC area and upstream portions of the San Jacinto River. Under the various surge scenarios based on Hurricane Ike, water surface elevation and floodplain area reductions ranged from 34 to 45% and 7 to 20%, respectively, with event scenarios of greater storm surge volume providing greater storm surge reduction benefit.