201-10 Data that Drives Decisions: Research, Monitoring, and Modeling Tools Used for Implementing Groundwater Policies that Mitigate Subsidence

Abstract:

The Harris-Galveston Subsidence District (HGSD) provides groundwater regulation to prevent further land subsidence in Harris and Galveston counties, southeast Texas, USA. HGSD has worked with academic institutions, local- state- and federal agencies, and private consulting firms to research subsidence mechanisms, monitor changes in the aquifer system and the land surface, as well as predict subsidence impacts of projected population growth along with associated increased water demand. Over the past fifty years, HGSD has utilized a variety of datasets to inform decision-makers on groundwater management strategies from advancements in data acquisition, to application of remote sensing technologies, to enhancements on groundwater flow and subsidence models. With the continued collaboration with water providers and regional water authorities, alternative water supplies, primarily surface water, have contributed to the successful mitigation of subsidence along the coastal areas, which measured over nine feet of subsidence in the 1900s to no subsidence since 2000. HGSD has built a framework that incorporates annual well pumpage from permittees, annual measurements of the aquifer system and continuous land surface monitoring presented in a publicly available report in addition to decadal regulatory reviews that model the impact of future water demand on the aquifer system and potential land subsidence. Results from these efforts drive policy decisions and provide insights into future research opportunities to minimize subsidence risk in evolving conditions.

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