Sediment Budget Analysis System

$2.8 MILLION PER YEAR POTENTIAL COST SAVINGS AT HOUSTON-GALVESTON SHIP CHANNEL

The Houston-Galveston Ship Channel serves the largest port in the Nation, the Port of Houston, and is maintained by the Corps’ Galveston District. Galveston Island contains about 30 miles of beaches and is located adjacent to the ship channel. Smart sediment management of the channel can benefit the integrity and resilience of adjacent barrier islands. Sediment budgets provide a foundational assessment of sediment magnitudes, rates of exchange, and pathways for coastal and waterway studies. They often form the basis used in local and regional planning, and engineering and design studies. A comprehensive budget provides accounting of the sources, sinks and pathways within a regional system.

PROBLEM: The Houston-Galveston Ship Channel was experiencing consistently high shoaling rates. At the same time, Galveston Island was experiencing severe erosion. The Galveston District needed to evaluate shoaling sources and opportunities for the beneficial use of dredged sediment. The district wanted to use engineering approaches to understand the physical processes at work on Galveston Island to quantify sediment needs for various beach nourishment alternatives.

SOLUTION: The Galveston District and ERDC utilized the Sediment Budget Analysis System (SBAS) to create a sediment budget to guide development of a sand management plan for Galveston Island. The SBAS provided a transparent way to document sediment sources, volume change and engineering activites such as dredging and placement, and share those details with study partners. Using SBAS, the Project Delivery Team determined numerous sediment management alternatives to lessen the amount of shoaling in the ship channel.

IMPACT: Sediment budgets provide better understanding of sediment sources, sinks and pathways; and can assist in more efficient sediment management in the region. The Galveston Park Board adopted the Sand Management Plan in 2015. If all alternatives are employed, it would keep about 690,000 cubic yards per year out of the channel, leading to a potential cost savings of $2.8 million per year (based on a representative dredging cost of $4 per cubic yard).