UH Geologists: Northwest ‘Burbs Still Sinking

Parts of northwestern Harris County are sinking at an unusual rate. Now a study from geologists at the University of Houston reveals that some points in Jersey Village are subsiding by more than two inches a year.

“If I try to sell my house, am I going to have to tell people that my house is sinking?”

That’s Agnes Donnely. She’s lived on Battlecreek Drive in Jersey Village for 28 years. Like most residents, she didn’t know that her neighborhood is sinking and is now worried about the value of her home.

“You know, I’ve planned on staying here for the rest of my life. But if Jersey Village is going to be a lake one day, I guess I better get me a boat.”

Three geologists from the University of Houston analyzed GPS data from 1995 to 2005. Dr. Shuhab Khan says it has long been known that the area is sinking, but the new study reveals the exact locations and also the rate of the subsidence.

“What we have done, we have used the latest GPS technology. We found out certain areas are not moving anymore or as fast. But this area, northwest of Houston, stands out because it’s subsiding rapidly.”

Khan says that as more and more people move to Northwest Harris County, the demand for groundwater rises as well. But developers have been pumping out the water faster than rain can replenish it. That leads to the subsidence.

Khan says two things might be making it worse: underground fault lines, and also underground salt domes. The domes cause the ground to slide more easily. While subsidence is happening in many urban areas around the world, the extraordinary sinking rate here is what’s worrying Khan.

He points at a map of Jersey Village showing blue circular areas where the ground is sinking. Those areas could see more flooding.

“Look at the shape of this. In the center it’s more subsiding; in the side, it’s less. So, we have a lot of rain, we have hurricanes, we have all those things. What happens with that water? That will not drain out.”

Subsidence 1906-2000
Image courtesy of Harris Galveston Subsidence District

Tom Michel is the Deputy General Manager of the Harris Galveston Subsidence District. He says the district’s plan is to reduce the percentage of groundwater needed for household use.

“Towards the end of 2004, 2005, 2006 time frame, we started seeing subsidence slow dramatically in those areas, because the City of Houston had converted some of their ground water pump-age over to surface water usage.”

Michel says that starting this year, 30 percent of drinking water in the entire region has to come from surface water. That water is collected from rivers and lakes and then purified for drinking, bathing and washing. Michel says the Subsidence District will re-examine the data in March, and will know then if the new plan is helping.

Reported by Florian Martin. Edited and voiced by Carrie Feibel.