The Galveston County office of Emergency Management, in a joint venture between Jefferson County and Galveston County, contracted Coastal Planning & Engineering (CPE) to conduct offshore geotechnical investigations between Sabine Pass and San Luis Pass to identify suitable and cost-effective sand resources for beach nourishment projects. The 90-mile long study area (10 miles offshore) was located between Sabine Pass and San Luis Pass.

Phase 1 of the investigation featured a geomorphic analysis of existing data and the construction of a GIS/MIS (Geographical Information Systems/Marine Information Systems) database. The development of a comprehensive GIS database is vitally important to data analyses that define spatial relationships and indicate the occurrence of beach compatible deposits. Sequence stratigraphy is used to determine the extent to which stratigraphic information provides indication of beach compatible sand bodies in the stratigraphic record.

Several potential sand deposits on the Texas continental shelf were identified as a result of this investigation. Nearshore deposits (e.g. San Luis and Galveston ebb-tidal shoals, parabathic ridges, and nearshore channel fill deposits)
represent the most cost effective options to restore eroded beaches. Deposits further offshore on the inner to middle shelf (e.g. Sabine Bank and Heald Bank, ridges offshore Galveston, Trinity and Sabine Valley System) contain large quantities of suitable sands, but they are not as cost-effective as nearshore deposits.

The innovative methodology applied here is an efficient tool for preliminary assessment of sand resources. Historical data displayed and analyzed in a MIS framework provides unique opportunities to summarize knowledge of geology and shelf geomorphology with existing geotechnical and geophysical data that facilitate identification of sand resources. This kind of understanding of seabed morphology and stratigraphy abbreviates the need to conduct random geophysical and geotechnical surveys over large expanses of the seabed and is more efficient and economical because only potential deposits are targeted.

The project was managed by John Lee and Tesa Duffey of Galveston County Emergency Management. The study is being coordinated with Jeff Waters of the Corps of Engineers (Galveston District) and Eddie Fisher of the GLO.

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