[Houston Chronicle - 28 May 2016] As torrential rains have pounded the city in consecutive years, leading to repeated, heavy and deadly flooding, this inconvenient fact contributes to the region's misery.Parts of Harris County have dropped between 10 and 12 feet since the 1920s, according to data from the U.S. Geological Survey.
State and local officials have made various efforts over the past 40 years to stabilize the ground, but some areas continue to sink - by as much as 2 inches per year.
Spring Branch, where Interstate 10 and Beltway 8 meet, has dropped 4 feet since 1975. Jersey Village, along Route 290 and to the west of Beltway 8, is almost 2 feet lower than it was in 1996. And Greater Greenspoint, where Interstate 45 intersects with Beltway 8, has given up about 2 feet in the last decade alone, according to USGS data.
"When you lose that much, it makes an area prone to floods when they weren't historically," said Mark Kasmarek, a hydrogeologist for more than 30 years with the USGS.
There is little mystery to why this is happening: The developing region draws an excessive amount of groundwater to keep itself quenched. Over the last century, aquifers here have lost between 300 and 400 feet, leaving the land to collapse.
The science behind this phenomenon is called subsidence.