Sinking grounds

More sources of surface water are essential, as well as aggressive water-saving measures.

Brownwood was once a suburb of Baytown until it sank. It happened slowly. At first, no one noticed that the glamorous subdivision built in the 1930s was slipping away, as reported by Chronicle editor Lisa Gray. Nor initially did oil executives who lived there link the sinkage to industry’s ravenous appetite for groundwater pumped out of the land.

But after the ground plummeted 10 to 15 feet, the bay crept up and eventually reclaimed some of the area’s fancy homes. Then came August 1983, and Hurricane Alicia swept over the peninsula destroying virtually all that was left.

With Brownwood as a cautionary tale, slowly over time, scientists and public officials learned a valuable lesson: The ground we build on is physically supported by the underground water supply. When that water supply plunges, the land slumps.

Back in the 1960s, people didn’t know why the ocean was reclaiming their homes. Now policymakers know why it happens, how to avoid it and roughly where it is happening. Granted: Growing communities need more water. But there’s no valid excuse for failing to enact measures to keep the ground solid underneath our feet.

Harris County has made tremendous progress in weaning off groundwater, but progress has been stronger in south and central Harris County than in the northern region which includes fastgrowing Spring and Tomball.

Northwest Harris County continues to pump billions of gallons from the Earth a year, as reported by Chronicle reporter Dylan Baddour. That region’s massive surface water project, dubbed the Luce Bayou Interbasin Transfer Project, should take pressure off groundwater supplies. But it’s still years away from completion.

Expanded sources of surface water are necessary, but mayors, city council members, regional water authority directors, and municipal utility district and other water supply district managers and board members — in other words, the people who have the authority and responsibility to provide water and who can enact water conservation measures — also need to become more ambitious about conserving this precious resources.

Outdoor watering is a major culprit, particularly automated systems that are set to water even if it’s raining. Some Texas cities have adopted adjusted water rates, which charge more for higher usage. Houston, whose rates are lower than many other major American cities, could do so, as well. Lawn watering can account for 50 to 80 percent of households’ summertime use, studies say.

Prudent management does make a difference, as illustrated by a new U.S. Geological Survey web portal featuring 40 years’ worth of Houston-area data. The data covering the years 1977 to 2016, shows the substantial recovery of groundwater levels since governmental action was taken to limit their decline, as reported by Baddour. Areas near the Houston Ship Channel have seen the aquifer climb to about 100 feet below sea level in 2016, up from nearly 300 feet below in 1977.

Damage from subsidence isn’t always as obvious as it was in the case in Brownwood. Subsidence also can contribute to flooding by disrupting drains and irrigation ditches; it can alter the flow of creeks and bayous, which may increase the frequency and severity of flooding; and it can damage roadways, bridges, building foundations and other infrastructure.

Although Brownwood residents no longer enjoy the sunsets overlooking the bay, and the lifestyle of fishing and sailing, the site has reopened as the Baytown Nature Center. A good spot for viewing migrant birds, the center is also a reminder of the folly of betting against nature.