Because subsidence occurs slowly over time, it is difficult to see its impact until the damage is already done. Once subsidence occurs, it is irreversible and has contributed to significant impacts on the greater Houston area, including:
- permanent loss of land elevation (i.e., Brownwood Subdivision in Baytown, Texas)
- damage to important infrastructure like homes, buildings, pipelines, roads, and bridges
- faulting
- disruption to the natural flow and drainage patterns; and
- contributing to increased flood risks
Our region’s first recorded subsidence occurred back in 1918 near Baytown, Texas. As the area grew, so did water demand, and subsidence became more of a concern; some areas sank over 9 feet within four decades, prompting the creation of the Harris-Galveston Subsidence District in 1975 to regulate groundwater near the coast. By the 90s, this area worked hard to diversify its water supplies, bringing in alternative water sources like treated surface water to meet its water demand and reduce reliance on groundwater, which resulted in stabilized subsidence rates. However, subsidence in our region has moved more inland as groundwater continues to be a primary water source until alternative water supplies become available.
Brownwood Subdivision in 1944 to 2002. Slide the arrows to see the impact of subsidence.