At high tide the waves lap through the upstairs bedrooms of the comfortable colonial home Dr. Jesse Kirkpatrick built on the shores of Crystal Bay before World War II. Since 1943, the land it rests on has subsided more than seven feet (three in the past ten years), so that today the house sits 50 feet out in the bay like some shipwrecked houseboat deserted by its crew. The Kirkpatrick home is one of 448 homes in Brownwood, a pleasant, wooded, middle-to-upper-middle-class subdivision of Baytown, twenty miles east of downtown Houston. Some of the nicest homes, those on a point where Crystal Bay meets Burnet Bay, have disappeared entirely. Around many of the remaining homes the owners have built walls of sandbags in what can only be an ultimately futile effort to keep out the waves now within a few feet of their doors.
It was inconceivable to the Kirkpatricks and to their neighbors that any disaster could be worse than the destructive tides and waves of Hurricane Carla which damaged so many of their homes in 1961. Across the Houston Ship Channel, however, the booming plants and industries of the world's largest petro-chemical complex and the nation's third largest port had set in motion an inexorable geologic process which destined their quiet neighborhood for the bottom of Galveston Bay. This great agricultural, industrial, and refining economy—and its population—have been fueled by 190 billion gallons of water a year, available easily and cheaply from industrial and municipal wells. These wells have steadily drained the Evangeline and Chicot aquifers (underground water storage systems) faster than they are refilled by annual rainfall. Each year the wells must go deeper to find water. Because of the region's gology, water is a vital structural componennt of the clay and sand underlying the land surface; when it is removed, the land sinks.
Brownwood, since it originally lay less than ten feet above sea level, felt the effects first. People who had painstakingly rebuilt their homes after Carla discovered that the bay was eating away at their land, inch by inch, year by year. As the ground sank faster—four inches a year—they stopped worrying about chinch bugs and routine maintenance and started building bulkheads and sandbagging their patios. Some families parked a car permanently on higher ground, kept their belongings in packing crates, and had local moving companies standing by to ensure their escape from another heavy storm or hurricane. Throughout the 1960s, as the plight of the people of Brownwood became palpably hopeless, geologists began making studies, engineers began making surveys, and politicians began making promises. Nothing substantial was done.
Today, however, the problem is much more serious than the plight of one neighborhood. The residents of Brownwood are not alone in living on the brink of certain natural disater. Over 20,000 acres of Houston-Galveston area land has already sunk, or will soon sink, beneath the waters of Galveston Bay and its estuaries. More than $100 million in property has been lost so far . In Kemah the U.S. Post Office is routinely flooded; in Texas City and Pasedena storm sewers now run in the wrong direction; at the San Jacinto Monument a University of Texas geologist was surrounded recently by leaping schools of mullet abd water up to his neck as he navigated the "walkway" around the reflecting pool of our state's independence shrine. Throughout the area, more than 1000 miles of faults activated by subsidence threaten residential and industrial structures, as well as the web of pipelines crisscrossing the ship channel on their way to fuel the great cities of the North and East.
The effects of subsidence are occuring steadily and gradually; the land sinks—and the faults separate—a few more inches each year. The truly catastrophic effects of subsidence, however, will come with the violence and killer destructiveness of Gulf hurricanes. As surely as summer turns to autumn, the majority of the land in the Houston-Galveston area will in the not-too-distant future (for a day or more) be buried beneath the storm-tossed waters of the Gulf of Mexico. The prospect speaks eloquently from contour maps of the region. The line marking high ground during a hurricane (land twenty feet above sea level) is steadily moving inland, and now in places begins more than ten miles from the present shoreline of Galveston Bay. Subsidence has made huge chunks of land which have never been flooded vulnerable to hurricane tides. According to David Benton of the National Weather Service in Galveston, "A massive hurricane will cross Galveston Island, sooner or later." When it does, the Johnson Space Center (elev. 15-25 feet), the Texas City refinery complex (elev. 5-15 feet), many of the industries along the upper ship channel (elev. 10-35 feet), and more than 1000 suqare miles of land will be under water.
Predictions on just how high hurricane tides will get vary according to the source. The U.S. Army Corps of Engineers has developed detailed projections for the most severe hurricane which it says could reasonably be expected to occur. The Crops predicts maximum tides on Galveston Island of fifteen feet, with nineteen feet at NASA and twenty feet in the upper ship channel area from Baytown to the turning basin on Clinton Drive. Subsidence means that land which would have been twenty-five feet out of water in such a hurricane twenty years ago would be inundated today. Hurricanes, however, have a nasty habit of being unreasonable: they may head straight over land at twenty miles an hour as Camille did, or just sit still, as Carla did. Both these recent hurricanes caused tides of more than twenty feet where they went inland; if Carla has crossed directly over Galveston Island (instead of 100 miles to the southwest) the tidal levels would have exceeded the Corps of Engineers' maximum figures by five feet. As Chester Pawlik of the Corps of Engineers' Galveston office says, "Sure, twenty-five foot tides are possible. Thirty-foot tides are possible. Even higher is possible. It would just be rare."