Time-Lapse Maps Show Growth of Subsidence in Houston Region

11/3/26 – Joe Higgs, a petroleum reservoir engineer with 30 years of experience, sent me a series of maps that show the expansion of subsidence in the Houston region since 1906. They show a small problem that started in Harris and Galveston Counties gradually grow until it engulfed the entire region.

Subsidence from 1906 to the 2020s

This simple sequence below underscores why we must not ignore subsidence. If you’re not yet affected, you will be.

All of the maps are compiled in this PDF. Scroll through the pages quickly and see the expansion in motion. It’s startling.

What is Subsidence and What Causes It?

Subsidence is a sinking of the ground beneath you. Withdrawing groundwater faster than nature replenishes it causes subsidence. As the water is removed, sand and clay in the soil become compacted. And once compacted, soil stays that way. Imagine smashing a brownie. It will never return to its original height.

*Dark lines represent Montgomery County’s total groundwater pumping. Notice how the increase coincides with the MoCo’s subsidence increase.*

Groundwater extraction in the Houston region has led to the irreversible loss of 12 cubic kilometers of groundwater storage – equivalent to 60 times the volume of Lake Houston.

What Effects Does Subsidence Have?

Individual homeowners may experience subsidence as foundation issues. Slabs settle and crack. Bricks separate. Driveways crack. Pipes break. Doors and cabinets won’t close. Wallboard buckles. Gaps appear in molding. Tile cracks.

Subsidence induced by groundwater pumping — *Woodlands faulting damage triggered by subsidence.*

On a wider scale, streets, sewers and pipelines shift and crack. Storm drains may start flowing backwards. Brownwood, a whole subdivision near Galveston Bay sank beneath the waves.

*Today, the area is uninhabitable. All the homes are gone. The area has been turned into a park.*

Differential subsidence can also form bowls in the landscape. Such bowls can collect water that contributes to flooding. Or they may slow runoff, causing floodwaters to rise beyond predicted levels.

Differential subsidence can even tilt the landscape behind dams. For instance, areas upstream from the Lake Houston Dam are sinking faster than the dam itself. So, the height of homes above the floodplain decreases, erasing the safety margin that engineers built into their design.

Can Subsidence Be Halted?

Yes. Subsidence can be halted. But it takes political will power. Prudent regulation. The cooperation of residents. And conversion to surface water.

The Harris-Galveston Subsidence District has proven that subsidence can be stopped. The first areas it regulated near the coast have largely stopped sinking. However, newly developed areas to the north and west in Montgomery, Fort Bend and Waller counties still sink at an alarming rate.

They lie beyond the regulatory reach of the Subsidence District. They still use groundwater instead of surface water. In the short run, it’s cheaper to drill a well than build a pipeline.

And the Lone Star Groundwater Conservation District in Montgomery County has no appetite to even acknowledge subsidence any more. They want to pump groundwater at a rate that’s three times higher than the rate of replenishment. It’s a slow motion problem in the making.

Meanwhile, in the long run, the cost of continually drilling wells deeper to chase vanishing water supplies adds up. Tax increases to cover those costs also add up. And the damage to infrastructure and homes? Well…nobody is adding those costs up. And because subsidence happens slowly, it’s easy to ignore. Until it’s not. When the well runs dry.

Transportation: The Solution to Subsidence

In the end, people realize that the solution to subsidence and long-term water security is transportation. Communities must build pipe l ines and canals to reservoirs, such as Lake Conroe, Lake Houston and Lake Livingston.

Surface water should be our primary supply. And groundwater should be our backup. Not the other way around.