Suburbs sinking at a substantial rate in The Woodlands, Spring, Katy and Mont Belvieu, study shows

Here's what we know

HOUSTON – The ground is sinking fast in some of Houston’s suburban neighborhoods.

According to a study led by Shuhab Kahn, professor of geology at the University of Houston, published in the academic journal Remote Sensing alongside some UH grad students, found that subsidence is happening at a significant rate.

Kahn’s team found substantial subsidence in Katy, Spring, The Woodlands, Fresno and Mont Belvieu.

“One side of his house was dripping and the other side was staying in the same spot,” explains Laura Norton, President of Municipal Utility District 47. “The damage just continues.”

Norton is also the creator of and she has been advocating for homeowners for the last five years, showing people what fault lines can do to properties and communities. She showed us a home where the homeowner had $50,000 worth of repairs because of the fault line it sits on. He had to add sections to his driveway, raise his foundation and add a step on the front porch. This particular fault line in the Woodlands runs through neighborhoods and even school parking lots.

“We’re sinking at half an inch a year,” noted Norton.

Houston area realtor, Michaela Green, says newer homebuyers are gravitating towards these suburbs of Houston.

“The Woodlands and Katy are growing so substantially because of affordability, access to great schools, entertainment and food,” explained Green. “They are great choices for new homeowners, especially ones with growing families.”

And because of the influx of people flocking to these suburban areas, more water is used.

According to Kahn, this increase in water usage is a huge contributing factor to subsidence or sinking land. The study also showed in addition to groundwater, oil and gas withdrawal were identified as the primary cause of the subsidence.

“It seems from most of the data that groundwater pumping is the main factor,” explained Khan.

The researchers used interferometric synthetic aperture radar (InSAR) data obtained from a European Space Agency satellite, which showed total subsidence of up to 9 cm to the north, northwest and west of Houston from 2016 to 2020. The subsidence rate was 2 cm a year. Khan says this also means there are hundreds of thousands of homes now susceptible to potential flooding anytime there is a significant rain event.

But although this data may sound scary, Khan says this is actually good news.

“If you know your area is going through subsidence that is a good thing because know there is a problem. There are steps to take and engineering is very advanced these days, " explained Khan. “If you know about subsidence you can take steps or measures with your local government to minimize it in the future.”

Khan and Norton both agree on one solution to help mitigate the subsidence in the future.

“Managing groundwater and mixing with surface water could be a better strategy,” says Khan.

“The solution to it is to take more surface water and less groundwater,” notes Norton.

Khan shared that the data showed a correlation between fault lines that were active and subsiding areas. He said they found that in areas that were subsiding, fault lines were also active and vice versa. The areas that did not experience as much subsidence did not have any active faults.

“Nobody would expect faults in Houston and we don’t know where the faults are until they appear. They are a bigger problem because faults can destroy buildings and destroy roads. After five or ten years the fault shows itself by cracking buildings cracking roads,” explained Khan. “Some of them are a few meters, some are several miles long.”

Khan explains that fault lines are just more vulnerable areas that with subsidence become even weaker, causing them to become active. Right now according to Khan and Norton, the Woodlands uses half surface water and half groundwater. Areas also experiencing increased subsidence like Katy, use mostly groundwater.

If you are buying a home that lives on a fault line, Green says realtors will usually disclose that information, if it is public knowledge. You can also check on FEMA’s website to see if the home is in a flood zone.

But as Khan said it’s common fault lines will stay dormant for years before they become active again. Norton advises home buyers to check the appraisal district website. There you can see what has happened to the home value over the years and determine if there are some concerning changes. She says it’s important to ask your realtor as many questions as possible before purchasing a home. Norton says the homes directly on the fault line are the ones that have structural issues but the homes in the sinking areas will experience flooding long term. It’s something she says is irreversible.

If you already own a home in areas experiencing more subsidence you can look at this interactive map from the University of Houston that shows where the subsidence is happening and where the fault lines are currently located.

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