Hurricane Barriers and Flood Barriers

Flood Technologies andf U.S. Engineering Solutions

concrete wall illustrated with black silhouette of person reaching for an unbrella blowing away
Banksy Illustration on Levee Wall in the Lower Ninth Ward in New Orleans. Chris Graythen/Getty Images

In an age of global warming and extreme weather, the risks of living near water have never been greater. Storm surge protection and hurricane barriers have been the solution for some communties, but at what aesthetic cost? Can artists and architects make engineering more beautiful? Examining the questions and exploring solutions will help us understand the real-world challenges surrounding the effects of global climate change.

Levees and Flood Walls

canal of water on left, a levee wall with grass in the middle, houses on the right, Overhead photo of repaired levee wall after the flooding from Hurricane Katrina
Repaired Canal Levee Wall Along the Lower Ninth Ward, New Orleans. Mario Tama/Getty Images

The devastation of Hurricane Katrina in 2005 brought many problems to lightt. Much of the destruction in New Orleans was a result of flooding from the levees breaking — a breach in an infrastructure that was meant to protect. Learning from the tragedies that beset New Orleans, we now understand that the best protection is a coordinated system, a combination of targeted local infrastructure designs and processes that work together in a disaster emergency. Levees and flood walls are not enough.

The Great Wall of Louisiana

waterway delta cut with a manmade barrier with openings
The Surge Barrier, the Great Wall of Louisiana in New Orleans. Mario Tama/Getty Images (cropped)

Between 2008 and 2013, the U.S. Army Corp of Engineers — the same group responsible for the inadequate levee system in New Orleans — completed a hurricane barrier nearly two miles wide across a mix of waterways about 12 miles east of downtown New Orleans. Called the Inner Harbor Navigation Canal Lake Borgne Surge Barrier, the concrete and steel hurricane barrier works in tandem with the levee system. The barrier is the first line of defense by mitigating the storm surges associated with hurricanes.

What is a Storm Surge or Storm Tide?

25 MPH speed limit sign poking up from raging waters
Storm Surges Don't Read Speed Limit Signs. Orjan F. Ellingvag/Corbis via Getty Images (cropped)

A hurricane is a low-pressure center. Over land, low-pressure centers are not strong enough to move earth. However, low-pressure centers that are over water can actually push and move the water. Hurricane-force winds blow water not only creating waves, but also creating a dome or surge of high water. Along with a normal high tide, a storm surge can create an extreme storm tide in addition to the waves blown by severe hurricane wind. Hurricane barriers provide protection to anticipated storm tides.

Is a Storm Surge a Tsunami?

A storm surge is NOT a tsunami or tidal wave, but it is similar. Storm surge is an abnormal sea level rise, usually caused by extreme weather. The super-high tide also has waves, but the waves are not as dramatically high as a tsunami. Tsunamis are literally "harbor waves" caused by an underground disturbance, like an earthquake. Extreme flooding is the result of both events.

Living Near Water

When we look at a map of where people live, it's not difficult to imagine how vulnerable life and property can be to severe weather. Although constructing tsunami-proof buildings along the shorelines is an option, a rising storm tide can be relentless. The U.S. National Hurricane Center has provided a Flash animated example of a Storm Surge (Flash plug-in required). In this animation, storm surge along with pounding waves are no match to the small barrier protecting the structure.

Fox Point Hurricane Barrier, Providence, Rhode Island

photo of bridge / open hurricane barrier in Providence, Rhode Island
Fox Point Hurricane Barrier, Providence, Rhode Island. Lane via flickr.com, Attribution-NonCommercial-NoDerivs 2.0 Generic (CC BY-NC-ND 2.0) (cropped)

In Rhode Island, Hurricane Sandy's 2012 mighty storm surge was blocked by a 1966 piece of engineering. The technology of hurricane barriers is an investment for any region, but see how they work.

The Fox Point hurricane barrier is in East Providence, Rhode Island, situated across the Providence River, which flows into Narragansett Bay. It is 3,000 feet long and 25 feet high. It was constructed between 1960 and 1966 to protect the city from a storm tide of 20 feet above sea level.

The system consists of three Tainter gates, five pumps for river water, and two 10- to 15-foot high stone and earth levees or dikes along the river's bank. At a cost of $16 million (1960 dollars), state and local government paid only 30 percent of the cost while the federal government subsidized most of the cost of the hurricane barrier system.

How Does It Work?

Three Tainter gates, also called radial gates, can close to provide a half mile long, 25-foot high barrier between the City of Providence and the waters from Narragansett Bay. Water flowing down the Providence River to the sea is pumped out as it builds up behind the closed gates. The pumping station, 213 feet long and 91 feet wide, is constructed of reinforced concrete and brick. Five pumps have a capacity of pumping 3,150,000 gallons of river water per minute into Narragansett Bay.

Each Tainter gate is 40 feet square and weighs 53 tons. Designed to curve outward toward the Bay to break the impact of the waves, the gates are lowered into place by electric motors and gravity at 1.5 feet per minute. It takes about 30 minutes to lower them but about two hours to raise the gates from a closed position, as gravity works against them being raised. If necessary, the gates can be lowered and raised manually.

Does a Hurricane Barrier Need a Pumping Station?

The design of any hurricane barrier depends on conditions. The pumping station at Fox Point is an important element to protecting the City of Providence. Without pumping out river water when the river is "dammed" by the gates, a reservoir would form and flood the city — just what Providence is trying to avoid.

The Tainter Gate

large wooden tainter gate, wooden shield with wooden posts attached
Historic Tainter Gate by Lake Menomin in Menomonie, Wisconsin. Emistuemke via Wikimedia Commons, Creative Commons Attribution-ShareAlike 4.0 International (CC BY-SA 4.0) cropped

The Tainter gate was invented in the 19th century by American engineer and Wisconsin native Jeremiah Burnham Tainter. The curved gate is attached to one or more truss-like, triangular framework pieces. The wide end of the triangle framework is attached to the curved gate, and the apex point of the truss rotates to move the gate.

The Tainter gate is also known as a radial gate. Gravity and the water pressure actually help move the gate up and down, as illustrated by Arif Setya Budi and also in the animation provided by the Dunn County Historical Society in Wisconsin.

Tainter Gates and Dams

close up of metal barrier from behind, with walkways for maintenance workers
Closed Tainter Gate at Rapel Dam in Chile. Avodrocc via Wikimedia Commons, Creative Commons Attribution 2.0 Generic (CC BY 2.0) cropped

A Tainter gate is also used in dams, so is a hurricane barrier also a dam? Yes, and no. A dam certainly is a water barrier, but dams and reservoirs generally are not constructed for emergency use only. The sole purpose of a hurricane barrier is for protection from a storm surge or storm tide. The City of Providence has defined two central functions for Fox Point:

  1. "to retard high tides from potential storm surges in Narragansett Bay"
  2. "to maintain river flow such that water levels do not get too high behind the barrier"

Government Partnerships

Like any construction project, a need must be acknowledged and funding must be realized before architecture and construction can begin. Before the Fox Point, the City of Providence was threatened every year. In September 1938, the New England Hurricane caused $200 million property damage and 250 deaths with only 3.1 inches of rain. In August 1954, Hurricane Carol caused $41 million property damage with flood tides at high tide, 13 feet above normal. The Flood Control Act of 1958 authorized construction of a barrier at Fox Point. The U.S. Army Corps of Engineers (USACE) took control on February 2010, saving the City of Providence hundreds of thousands of dollars each year. The City maintains the dike and levee system.

The Vertical Lift Gate

an open vertical gate in a wall of concrete, water on either side of the wall
A Vertical Gate, Inner Harbor Navigation Canal Lake Borgne Surge Barrier, New Orleans, Louisiana. Julie Dermansky/Corbis via Getty Images (cropped)

A vertical lift gate is similar to a Tainter gate in that it raises and lowers to control the flow of water. While a Tainter gate is curved, however, a vertical lift gate is not.

The gate shown here, the Bayou Bienvenue gate, is part of a massive $14.45 billion project in New Orleans — the Inner Harbor Navigation Canal - Lake Borgne Surge Barrier, also called The Great Wall of Louisiana. The concrete barrier wall built by the U.S. Army Corps of Engineers is nearly two miles long and 26 feet high.

Floods and storm surges are not unique to the United States nor to North America. Throughout the world engineers have found ways to control flooding. In an era of extreme weather, this type of problem-solving is a thriving area of engineering study.

Flood Barriers and Warning Systems

A person walks through a flooded street after Hurricane Irene on August 28, 2011 in the Red Hook neighborhood of the Brooklyn borough of New York City.
Flooding in Brooklyn. Spencer Platt/Getty Images (cropped)

Why does a large urban area like New York City have no storm surge protection? In 2012, the storm surge from Hurricane Sandy flooded the streets, subways, and infrastructure of the largest city in America. Since then, working groups have been studying the feasability of a flood barrier in New York Harbor. Nevermind that other Industrialized countries around the globe have had high-tech solutions for flood control for years. 

Humans have a love hate relationship with water — nature's abundant compound is necessary for life but scores of people die from water-related events. Ten people drown unintentionally every day. Car accidents from flash floods and extreme weather are unpredictable. Or are they?

It seems that anyone can stop rising waters. A quick Google search for "flood barrier walls" finds an array of products from Home Depot, Ace Hardware, Amazon, and larger, commercial companies.

It wasn't that long ago that communities used sirens to warn of weather-related dangers. Some communities today continue to use this simplictic approach to flooding. With a mix of localized cameras (often on drones), mapping software, and disaster alert applications, companies such as Beholder Technology headquartered in Austin, Texas offer "remote situational awareness" to communities — which is to say they warn you about flooded roads and dangerous situations before the emergency crews can even get there. Disaster apps are considered high-tech solutions in the United States, but wouldn't hurricane barriers be more helpful?

Sources

  • Emergency Management Agency, City of Providence, November 5, 2012
  • Fox Point Hurricane Barrier Facts, City of Providence at www.providenceri.com/efile/705
  • Update Report for Rhode Island, U.S. Army Corps of Engineers, New England District, July 31, 2012 at www.nae.usace.army.mil/news/Reports/ri.pdf
  • U.S. Army Corps of Engineers. IHNC - LAKE BORGNE SURGE BARRIER, Updated June 2013, http://www.mvn.usace.army.mil/Portals/56/docs/PAO/FactSheets/IHNC-LakeBorgneSurgeBarrier.pdf
  • Centers for Disease Control and Prevention. "Unintentional Drowning: Get the Facts." April 28, 2016, https://www.cdc.gov/homeandrecreationalsafety/water-safety/waterinjuries-factsheet.html