Like a lot of smart people, during and after Hurricane Harvey, Arturo Leon put a lot of thought into potential solutions to a problem that has confounded the Bayou City for decades: how to keep water from rushing into the city from watersheds west of town. And the UH civil engineering professor found himself coming back to an invention that is not only not new, but, in fact, ancient.
This brilliant bit of engineering is none other than the siphon, an upside-down U-shaped tube that, when placed in two separate vessels, causes liquid to flow upward out of one, into the other, thanks to pressure differences and the force of gravity. Egyptian art from 1500 B.C. depicts people using siphons to move liquids such as oil and wine from large earthenware storage jugs, while relics from ancient Greek and Roman cities indicate they employed siphon systems for both aqueducts and early plumbing.
Leon says the principle could also work for flood mitigation in the Houston area. “I’m not saying this is going to solve the problem of flooding in Houston entirely,” he says. “It won’t. It’s going to take a lot of different solutions coming together to do that. But it will help significantly.”
The idea is to turn old Katy Prairie rice fields into temporary holding tanks, which, during the next storm or hurricane, would hold thousands of gallons of water until the rest of the bayou system and watershed drains, allowing it to handle more water. Once it’s time for that water to be released, U-shaped tubing on the lip of the rice field banks would be opened via remote control and the liquid would be sucked out and released, no pump required.
While such a solution wouldn’t have stopped Harvey’s initial flooding, Leon acknowledges, it would have mitigated the strain on the Addicks and Barker reservoirs west of the city—which later had to be released, flooding thousands of homes in west Houston—and cut the amount of water coming down through the watersheds.
Vast swaths of the Katy Prairie, a system of prairies and wetlands that originally held thousands of gallons of water, were turned into rice fields early in the 20th century, but modern satellite maps show that many have been left lying fallow over recent decades, mostly because of drought and the high cost of growing the crop. “You can’t go back and put all of the wetlands that have been destroyed back in,” he says, “but this would offer an imitation, a substitute.”
Leon acknowledges that his big idea isn’t flashy, but he contends that if even a portion of the landowners agreed to let their old rice fields be made into either temporary or permanent holding tanks instead of selling the land to developers, it would go a long way toward taking some of the pressure, and the water, off of Houston during the next big flood.
Leon has pitched the idea to officials with Harris County Flood Control, the San Jacinto River Authority, and the Katy Prairie Conservancy. This month, he and his students are planning to work with the conservancy to conduct remote-controlled tests using a siphon in one of the defunct rice fields.
His solution could be installed relatively quickly and cheaply, compared to other, multi-million-dollar, years-long proposed projects, including a coastal barrier system (which wouldn't protect Houston from Harvey-style floods) and a third reservoir on Cypress Creek. But a siphon system would need backers, including some sort of enticement from the state to get landowners to allow these flood waters to be stored on their property. No fix is easy at this point.
Leon has also pitched other possibilities to officials with the Texas Department of Transportation, including a raised highway that would run down to the Houston Ship Channel and could be closed off and turned into a high-tech aqueduct when necessary. “They said I was crazy, that it would never work,” he says. “But you never know, people are going to keep moving here from other places, and the area is going to keep flooding. Maybe my idea sounds crazy now, but in 50 or 100 years, they might come back and use it. It might not seem so crazy then.”