The Harris-Galveston Subsidence District (HGSD) is a special-purpose district created by the Texas Legislature in 1975 and is authorized as a groundwater regulatory agency to cease ongoing and prevent future subsidence in Harris and Galveston counties.  In addition, HGSD provides water conservation, education, and outreach programs to underscore the importance of water conservation in the community.

HGSD continues its mission to prevent subsidence in our area by enforcing reasonable groundwater regulation, providing water conservation programs, and conducting science-based water planning so that future water demands can be fulfilled while minimizing the risk of subsidence. The District is successful in doing this through collaboration with regional water providers, local, state, and federal agencies, along with university research programs.

In the greater Houston-Galveston region, land subsidence is caused by the substantial, long-term withdrawal of groundwater. When we pump large amounts of water from the aquifers beneath us, we pull water out of layers of clay, which causes the clay to compact. This compaction is seen at the surface as subsidence and has contributed to increased flooding, damage to our roads, and infrastructure issues in our area.