How Engineers Stop Floods: High-Tech Solutions

Every year a community in some part of the world is devastated by catastrophic flooding. Coastal regions are prone to destruction at the historic levels of Hurricane Harvey, Hurricane Sandy, Hurricane Florence, and Hurricane Katrina. Lowlands near rivers and lakes are also vulnerable. Indeed, flooding can happen anywhere it rains.

As cities grow, floods become more frequent because urban infrastructure cannot accommodate the drainage needs of land that is paved. Flat, highly developed areas like Houston, Texas leave the water with nowhere to go. The predicted rise in sea levels jeopardizes streets, buildings, and subway tunnels in coastal cities like Manhattan. Moreover, aging dams and levees are prone to failure, leading to the kind of devastation that New Orleans saw after Hurricane Katrina.

There is hope, however. In Japan, England, the Netherlands, and other low-lying countries, architects and civil engineers have developed promising technologies for flood control — and yes, engineering can be beautiful. One look at the barrier in the Thames River and you'd think it was designed by a Pritzker Prize-winning modern architect.

The Thames Barrier in England

An aerial view of the Thames flood barrier to the east of the Millennium Dome and the city on April 20, 2007 in London, England. — Mike Hewitt/Getty Images (cropped)

In England, engineers designed an innovative movable flood barrier to prevent flooding along the Thames River. Made of hollow steel, water gates on the Thames Barrier are normally left open so ships can pass through. Then, as needed, the water gates revolve shut to stop water flowing through and to keep the level of the Thames River safe.

The shiny, steel-clad shells house the hydraulic rocker beams that turn the giant gate arms to revolve the gates open and closed. A partial "underspill position" allows some water to flow underneath the barrier.

The Thames Barrier gates were constructed between 1974 and 1984 and have been closed to prevent floods more than 100 times.

Watergates in Japan

orange-red barriers in body of water — Chikako Nobuhara/Getty Images (cropped)

Surrounded by water, the island nation of Japan has a long history of flooding. Areas on the coast and along Japan's rapidly-flowing rivers are especially at risk. To protect these regions, the nation's engineers have developed a complex system of canals and sluice-gate locks.

After a catastrophic flood in 1910, Japan began exploring ways to safeguard the lowlands in the Kita section of Tokyo. The picturesque Iwabuchi Floodgate, or Akasuimon (Red Sluice Gate), was designed in 1924 by Akira Aoyama, a Japanese architect who also worked on the Panama Canal. The Red Sluice Gate was decommissioned in 1982 but remains an impressive sight. The new lock, with square watch towers on tall stalks, rises behind the old.

Automated "aqua-drive" motors power many of the water-gates in flood-prone Japan. Water pressure creates a force that opens and closes the gates as needed. Hydraulic motors don't need electricity to run, so they aren't affected by power failures that can occur during storms.

Oosterscheldekering in the Netherlands

bright blue waters and sky, wind turbines near barrier across water — Philippe Clement/Nature Picture Library/Getty Images

The Netherlands, or Holland, has always battled the sea. With 60 percent of the population living below sea level, dependable flood control systems are essential. Between 1950 and 1997, the Dutch built Deltawerken (the Delta Works), a sophisticated network of dams, sluices, locks, dikes, and storm surge barriers.

One of the most impressive Deltaworks projects is the Eastern Scheldt Storm Surge Barrier, or the Oosterschelde. Instead of building a conventional dam, the Dutch constructed the barrier with movable gates.

After 1986, when the Oosterscheldekering (kering means barrier) was completed, the tidal height was reduced from 3.40 meters (11.2 feet) to 3.25 meters (10.7 feet).

The Maeslant Storm Surge Barrier in the Netherlands

waterway lined with wind turbines great white gates opened to allow boat to go through — Mischa Keijser/Getty Images (cropped)

Another example of Holland's Deltaworks is the Maeslantkering, or Maeslant Storm Surge Barrier, in the Nieuwe Waterweg waterway between the towns of Hoek van Holland and Maassluis, Netherlands.

Completed in 1997, the Maeslant Storm Surge Barrier is one of the largest moving structures in the world. When the water rises, the computerized walls close and water fills tanks along the barrier. The weight of the water pushes the walls firmly down and keeps water from passing through.

The Hagestein Weir in the Netherlands

overhead photo of large metal twirly barrier across a waterway — Frans Lemmens/Getty Images (cropped)

Completed in about 1960, the Hagestein Weir is one of three movable weirs, or dams, along the Rhine River in the Netherlands. The Hagestein Weir has two enormous arched gates to control water and generate power on the Lek River near the village of Hagestein. Spanning 54 meters, the hinged visor gates are connected to concrete abutments. The gates are stored in the up position. They rotate down to close the channel.

Dams and water barriers like Hagestein Weir have become models for water control engineers around the world. Hurricane barriers in the United States have long used gates to mitigate flooding. For example, the Fox Point Hurricane Barrier in Rhode Island used three gates, five pumps, and a series of levees to protect Providence, Rhode Island after Hurricane Sandy's powerful 2012 surge.

MOSE in Venice

two of the flood barrier gates of The MOSE are lifted for the first time during a press conference on October 12, 2013 in Venice, Italy. The Mose project works towards protecting Venice from high tides and flooding. — Marco Secchi/Getty Images (cropped)

With its famous canals and iconic gondolas, Venice, Italy is a well-known watery environ. Global warming threatens its very existence. Since the 1980s, officials have been pouring money into the

Modulo Sperimentale Elettromeccanico or MOSE project, a series of 78 barriers that can rise collectively or independently across the lagoon opening and curtail the rising waters of the Adriatic Sea.

The Experimental Electromechanical Module began construction in 2003 and sediment and corroded hinges have already become problematic, even before complete implementation.

Alternative to Sand Bags

Raised flood barrier along a narrow river by a roadway — Mark Williamson/Getty Images (cropped)

The River Eden in northern England has a tendency to overflow its banks, so the town of Appleby-in-Westmorland set out to control it with a modest barrier that could easily be raised and lowered.

In the United States, solutions to potential flooding often involve sand — piled bags of sand, heavy machinery creating sand dunes on ocean beaches, makeshift levees being built in a panic. Other countries more simply incorporate technology in their building plans. Can U.S. engineering solutions to flood control be more high-tech?