Each year, the Harris-Galveston Subsidence District publishes an Annual Groundwater Report to provide the latest information on subsidence in our region. The Annual Groundwater Report encompasses data collected for the previous calendar year and includes the following elements:
- Climatic Conditions – To inform what climate conditions were for the reported year, because factors like precipitation or droughts can affect water demand for that year.
- Water Use – Using the pumpage reports submitted by permittees to inform on water demand, water use (public, industrial, or irrigation), and water supplies (groundwater or alternative water supplies like treated surface water or reclaimed water) that were used to meet this demand.
- Water Levels – The USGS provides the latest aquifer water-level data showing what happens beneath the surface in the aquifers from which we draw water. This part of the report demonstrates that in areas where groundwater was heavily pumped, water levels in the aquifer decline, leading to compaction and ultimately, subsidence.
- Measured Subsidence – The District utilizes a subsidence monitoring network to track land surface changes and is able to calculate the latest subsidence rates. This is mapped and published each year on our website as an interactive subsidence map showing where subsidence is currently occurring.
The results of the Annual Groundwater Report ultimately tell the story about our region’s subsidence mitigation efforts and help to better inform local decision-makers with data that can be used to build a more resilient community. In areas that have reduced their reliance on groundwater, little to no subsidence occurs, whereas in areas that still rely on groundwater as their primary water source, subsidence continues.
Annual Groundwater Report Process:
- Permittees are required to submit their Annual Pumpage Reports by January 31st each year. This data is then analyzed and used to build the Annual Groundwater Report.
- By late April, the District presents the findings of the Annual Groundwater Report at a public hearing. The public may provide testimony, evidence, exhibits, comments, or other information in-person at the public hearing or via email submission before the record closes in early May.
- The HGSD Board of Directors will consider a resolution to approve the Annual Groundwater Report at its regular board meeting scheduled for the second Wednesday of May.
- Upon Board approval, the report, along with the updated interactive subsidence map, will be published to HGSD’s website in the section below.