Houston, we have a problem: Texas city sinking faster than any other major US city

Yahoo

09-05-2025

Some of the biggest U.S. cities are sinking, and one Texas city is sinking faster than the others.
Known scientifically as land "subsidence," the most common cause of the sinking is "massive ongoing groundwater extraction," according to a study published in Nature Cities May 8 — though other forces are at work in some places. The issue is not limited to coastal cities impacted by rising sea levels, either. Several inner cities are also experiencing the phenomenon.
In all 28 cities included in the analysis, at least 20% of the urban area is sinking. In 25 of those, at least 65% are sinking.
The study is the first of its kind, according to its lead author Leonard Ohenhen of the Lamont-Doherty Earth Observatory.
"This is the first high-resolution, satellite-based measurement of land subsidence across the 28 most populous U.S. cities, and for several of these cities, it is the first time we have such detailed insights," Ohenhen told USA TODAY on May 7.
He said the study also "offers critical information for urban planning, infrastructure adaptation, and hazard preparedness."
Here's what the data revealed about the country's sinking cities.
The nation's fastest-sinking city is Houston, with more than 40% of its area dropping more than 5 millimeters (about 1/5 inch) per year, and 12% sinking at twice that rate.
Some localized spots are going down as much as 5 centimeters (2 inches) per year, according to the study.
Two other Texas cities, Fort Worth and Dallas, are not far behind.
Subsidence is often called an 'invisible threat' because it can go unnoticed for long periods, Ohenhen said. "Here, (in the study), we are making it less invisible."
When land shifts downward, even just a little bit, the structural integrity of buildings, roads, bridges, and dams can be profoundly impacted, said Ohenhen, a geosciences graduate student.
Ohenhen told USA TODAY that "some early warning signs (of subsidence) that are often overlooked include: Cracks in walls, foundations, or around windows and doors, uneven or sloping floors; doors and windows that no longer close properly, warped roads or buckling pavement, tilting fences or utility poles, and fire hydrants sticking out more than they once did."
Generally, according to a statement from Lamont-Doherty, it happens as water is withdrawn from aquifers made up of fine-grained sediments; unless the aquifer is replenished, the pore spaces formerly occupied by water can eventually collapse, leading to compaction below and sinkage at the surface.
In Texas, the problem is exacerbated by the pumping of oil and gas, the study says.
A few cities on the study's map — San Jose, Memphis and Jacksonville — are depicted with green dots, which indicate uplift.
"The uplift we detect is an average across the city and is small in these cities: 0.1 to 0.3 millimeters per year, which is almost negligible," Ohenhen said. "We can just say 0 millimeters per year, so on average stable. It does not mean the entire city is rising uniformly."
"A lot of small changes will build up over time, magnifying weak spots within urban systems and heighten flood risks," said Ohenhen. "This subsidence can produce stresses on infrastructure that will go past their safety limit," he added.
The researchers say that continued population growth and water usage, combined with climate-induced droughts in some areas, will likely worsen subsidence in the future.
"As opposed to just saying it's a problem, we can respond, address, mitigate, adapt," said Ohenhen. 'We have to move to solutions."
The study provided maps of each city and where land subsidence poses the highest risks to infrastructure, as measured by vertical land motion (VLM). Negative VLM indicates sinking, while positive VLM indicates uplift.
On the following maps, uplift is represented from green (0 millimeters per year) to purple (4 millimeters per year) and sinking is represented from yellow (-1 millimeters per year) to red (-6 millimeters per year).
— USA TODAY's Doyle Rice contributed to this report.
This article originally appeared on Austin American-Statesman: 3 Texas cities are sinking faster than other big US cities: See maps