# Levees and Flood Control Devices



## woutero

In january 1995 high water levels in the rivers Waal and Rhine lead to a near failure of the Dike Ring 43 (see map above). 250.000 people were evacuated. Fortunately the dike did not break. Since then, river dikes have been strengthened.

The most populous dike ring is number 14, with about 4,5 million inhabitants. There is no evacuation plan, because the infrastructure is insufficient for handling that many people. However, probably not all land within the dike ring would flood, and especially in cities, there are often higher grounds to be found.


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## diablo234

Construction of the Seabrook Floodgate in New Orleans. This is to keep the waters of Lake Pontchartrain out of the Industrial Canal.


Seabrook Floodgate Complex by USACEpublicaffairs, on Flickr

The rebuilt 17th street canal in New Orleans. The breech in the levees from Hurricane Katrina took place here.


New and improved 17th St canal by ianqui, on Flickr

This is what the floodwall looked like before Katrina.









This is what the floodwall looked like after it was breeched by the storm surge.










A memorial plaque at the location of the floodwall breach.









An Elevation Map of New Orleans.


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## Slagathor

diablo234 said:


> The River Walk in San Antonio was actually built with flood control in mind after a disastorous flood in 1921. Instead of building over the river they decided to make it a public space and added several locks as well in addition to several channels in case the water level gets to be too high. Now it has become a tourist attraction in it's own right.
> 
> http://upload.wikimedia.org/wikipedia/en/thumb/7/70/Riverwalk20.jpg/400px-Riverwalk20.jpg
> 
> http://upload.wikimedia.org/wikiped...ver_Walk_Museum_Stretch_under_bridge_2009.jpg
> 
> http://upload.wikimedia.org/wikiped...Antonio.jpg/800px-Casa_Rio_in_San_Antonio.jpg
> 
> http://farm3.static.flickr.com/2207/2379016426_356d84bb11.jpg


That's extraordinarily pretty.


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## diablo234

Slagathor said:


> That's extraordinarily pretty.


Yeah it's a pretty nice asset to the city not to mention a huge tourism drawl. And to think that city leaders talked about paving over the river back in the 1930's.


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## woutero

Here are some more pics of dutch flood control.

The already mentioned Maeslantkering, protecting Rotterdam from ocean storms:

Closed:









Opened:









Oosterscheldekering (closing off Oosterschelde from the North Sea when closed):


















Afsluitdijk:









Some of the older ways to keep our feet dry:

Traditional: wind mill (many still in use as backup):









Industrial revolution: Steam powered pumps:









Modern water pump (Gemaal) to pump rainwater out of the polder into higher level water (Boezem):









Schematich image of a polder:


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## woutero

And here is another interesting one: The Balgstuw, closing the mouth of the river IJssel off from the IJsselmeer, protecting the low lying areas around Kampen and Zwolle from water accumulation through storms from the west.

It is a big inflatable balloon that normally rests under water, but can be pumped up when needed:


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## erka

Another interesting Dutch defense line is the so called "slaperdijk" (sleeper dike). It is an inland dike, which once was the main defense dike but became obsolete when newer and higher dikes were built more outlandish.

Those inland dikes (sometimes centuries old) were not torn down but remained in place as a second line of defense. So when a Deltadike breaks, the old dikes can hold the flood or slow the flood down, giving more time to evacuate or rescue people.

Example:










In this case, the road can be shut with logs that are kept in reserve in the dike.

There are thousands of sleeper dikes.


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## diablo234

As an additional defense from storm surge, New Orleans is planning to revitalize and restore wetlands.



> *Cypress swamp near Lower 9th Ward will be restored as hurricane defense*
> 
> Published: Thursday, November 10, 2011, 9:00 PM Updated: Thursday, November 10, 2011, 9:05 PM
> By Mark Schleifstein, The Times-Picayune
> http://www.nola.com/environment/index.ssf/2011/11/cypress_swamp_near_lower_9th_w.html
> 
> Local leaders announced Thursday the beginning of a project to restore a key area of cypress swampland near the Lower 9th Ward, an effort they called essential to protecting the metro area in the event of another major hurricane.
> 
> Swinging shovels full of dirt, New Orleans Mayor Mitch Landrieu and St. Bernard Parish President Craig Taffaro said the eventual restoration of the 30,000-acre triangle of the once-vibrant Central Wetlands will be part of the several lines of defense that will keep the area safe from storm surge.
> 
> The first phase, which will restore 2,300 acres, will cost $10 million and will be paid for by the federal Coastal Impact Assistance Program, which is financed by offshore oil revenue. Another $30 million will be made available to expand the effort in the next few years.
> 
> “This is one of those bright spots where governments join together, crossing parish lines in Louisiana, and do something good for the public, good for the future of all of our communities,” Taffaro said.
> 
> “It really sends a message to the rest of America that its critically important that we rebuild all of Louisiana, all of New Orleans, all of St. Bernard because we all have common threats,” Landrieu said.
> 
> In 1956, before the completion of the Mississippi River Gulf Outlet, the Central Wetlands contained about 8,000 acres of swamp, 7,600 acres of freshwater marsh, 4,000 acres of brackish and salt marsh, and more than 1,000 acres of forest. The MR-GO cut through several natural ridges in St. Bernard Parish, funneling salt water into the area, where it killed cypress and freshwater marshes. By 1978, only 28 acres of forest remained.
> 
> The project’s first phase involves raising the soil level in two patches of the sunken triangle so that bald cypress trees and freshwater wetland plants can survive. The triangle is formed by the 40-Arpent Levee and the levee adjacent to the Mississippi River-Gulf Outlet and Gulf Intracoastal Waterway that follows the historic path of Bayou Bienvenue.
> 
> ..........


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## diablo234

Work on the Lake Borgne storm surge barrier just outside of New Orleans is nearly complete.









http://www.nola.com/environment/index.ssf/2011/06/gulf_intracoastal_waterway_at.html



> *2011: New hurricane protection system is built*
> Published: Monday, January 23, 2012
> 
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> An $8 billion re-engineered levee system came on line for hurricane season, six years after its predecessor failed miserably to protect the area from Hurricane Katrina. A chastened Army Corps of Engineers admitted that design, construction and maintenance flaws caused the old system to fail.
> 
> The Corps of Engineers worked feverishly to meet a 2011 congressional deadline to have a new, stronger system in place to protect the area from a 100-year storm.
> 
> ***
> 
> The keys to the new system are two new structures designed to keep the east and west banks protected from storm surge. The Lake Borgne Surge Barrier, also called The Great Wall of Louisiana, is a nearly two-mile-long, 26-foot-high barrier to prevent the kind of flooding that ravaged the Lower 9th Ward. The West Closure Complex in Belle Chasse will prevent the Harvey Canal from inundating the West Bank. Giant pumps are used to get rainwater runoff past the barrier.
> 
> [...]


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## diablo234

*LDP West Closure Complex*


26photo by Team New Orleans, US Army Corps of Engineers, on Flickr


23photo by Team New Orleans, US Army Corps of Engineers, on Flickr


11photo by Team New Orleans, US Army Corps of Engineers, on Flickr


IMG_0988 by Team New Orleans, US Army Corps of Engineers, on Flickr


10.28.11 ASABE WCC tour by Team New Orleans, US Army Corps of Engineers, on Flickr


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## diablo234

The Fox Point Hurricane Barrier in Providence, Rhode Island.



> The Fox Point Hurricane Barrier is a 3,000-foot (910 m) long tidal flood barrier spanning the Providence River in Providence, Rhode Island, located 750 feet (230 m) upstream from Fox Point. It was constructed between 1960 and 1966 to protect the low-lying downtown area of the city from damaging storm surge and floods associated with hurricanes and other major storm events.
> 
> The Fox Point Hurricane Barrier consists of five main parts: river gates, rock and earthen dikes along each shore, vehicular gates along each shore where roads pass through the dikes, canal gates at the west end of the barrier associated with the nearby electric power station, and a pumping station to control the flow of water.
> 
> http://en.wikipedia.org/wiki/Fox_Point_Hurricane_Barrier


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## duozhuchen

General sea ladder is to consider how the design height of it?


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## diablo234

Some videos on the Seabrook Floodgate floodgate and IHNC Lake Borgne Surge Barrier in New Orleans.


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## diablo234

As part of the new MOSE Project new flood control devices being tested on the Venetian Lagoon in Italy. This will protect the city of Venice against rising tides from the Adriatic Sea.

















http://en.wikipedia.org/wiki/MOSE_Project


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## diablo234

Ōshimakawa Floodgate in Tokyo, Japan.


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## diablo234

New floodgates and levees planned for Southwestern Louisiana.



> *Floodgates planned to slow storm surge from Vermilion Bay*
> 
> Larger levee project planned for Iberia
> 
> By Richard Burgess
> [email protected]
> http://theadvocate.com/news/acadiana/7692247-123/floodgates-planned-to-slow-storm
> 
> December 02, 2013
> 
> 0 Comments
> 
> 
> LAFAYETTE — Two flood gates are planned in Iberia and Vermilion parishes that supporters say could hold back some of the storm surge such as when water pushed into homes when Hurricane Rita hit southwest Louisiana in 2005.
> 
> The Iberia Parish Levee, Hurricane and Conservation District is moving forward with the design and permitting of a new floodgate on the Delcambre Canal, and the Vermilion Parish Police Jury has laid the groundwork for a companion project on Bayou Tigre.
> 
> The two waterways serve as routes for hurricane storm surges to push inland from Vermilion Bay.
> 
> The idea is to build a large structure that can be closed as a hurricane approaches, making a temporary dam of sorts to hold back the water.
> 
> In Iberia Parish, the floodgate on the Delcambre Canal is part of a larger planned project to build a 26-mile levee across the parish.
> 
> “This is our first stake in the ground,” said Patrick Broussard, with the Iberia Levee, Hurricane and Conservation District.
> 
> The levee project is estimated to cost $420 million.
> 
> The scaled-down plan to start with just the floodgate comes after Iberia Parish voters in April shot down a proposed 5-mill property tax and half-cent sales tax to fund the overall project.
> 
> Broussard said the goal is still to build the 26-mile levee, but the floodgate will offer protection to one of the lowest and most flood-prone coastal areas.
> 
> The Iberia Parish levee district has about $1.2 million in local and state funds for the floodgate on the Delcambre Canal.
> 
> .....


..


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## Kennethkbryant

Nice locations... Great collections


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## diablo234

Since wetland restoration plays a huge part in reducing storm surge and flooding I thought I should post this video.






Basically they are using recycled plastic materials to create new marshland. The material will float on the surface of the water and the roots from the plants will then eventually anchor the plants to the ground.


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## diablo234

Some photos of the new completed flood control devices in the New Orleans area, along with an accompanied article explaining how these new structures should protect the city against any 100 year flood/storm surge event.



















*Seabrook Floodgate Complex*



















*Lake Borgne Barrier*





































*The Gulf Intracoastal Waterway West Closure Complex south of New Orleans*

*NOLA.com: Upgraded metro New Orleans levees will greatly reduce flooding, even in 500-year storms*



> Metro New Orleans approaches the busiest period of the 2013 hurricane season with the best flood control system of any coastal community in the United States: A $14.5-billion network of levees, floodwalls and pumps that nearly eliminates flooding for most so-called 100-year events and substantially reduces flooding from much larger hurricanes.
> 
> But that system has serious limitations, officials say. And the region's natural defenses, the wetlands that once gave it miles of surge-absorbing marshes, have never been as decimated. That's why officials are asking residents to respect the remaining storm risk as the area enters the six-week window, peaking Sept. 10, during which most of its past storms have made landfall.
> 
> Key engineers involved in the design of the improved levee system have good and even better news: The massive system offers near-complete protection from flooding from so-called 100-year storm surge event, one with a 1 percent chance of occurring in any given year. The improved levees also offer a significant reduction in flooding from the much more damaging 500-year surge event, one larger than Hurricane Katrina, according to computer modeling by the U.S. Army Corps of Engineers.
> 
> ...............


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## ChasingCars

As mentioned numerous times, The Netherlands is a country that (as its very name suggests) is low, flat and therefore very prone to floods. Actually, the whole western part of the country (which is by far the most densely populated area with over 8 million people) is in fact a large river delta, in which some of Europe's largest rivers meander their way into the North Sea. 
Most important rivers are the Rijn (Rhine), Maas (Meuse) and Schelde (Scheldt) rivers, all spreading into multiple branches, flowing into the North Sea.
This means that the threat of flooding is coming from two sides: from the North Sea in case of a storm surge, but also from rivers, mostly in case of excessive rainfall or melting snow anywhere in their drainige basins.
For decades, Dutch civil engineers were in a constant 'fight' against the water, resulting in building dikes and dams. But as water levels are rising every year, these dams had to be higher and higher, making the cost of building dams, acquiring extra land and so on to explode.
Some years ago, the idea of 'fighting' against the water became old-fashioned. Engineers began to realize that they would ultimately lose the battle, as dikes simply cannot be enlarged forever.
Thus, they came up with a new plan, which (in short) consists of two main parts:
1. giving rivers more space by widening and dredging rivers and by creating spill area's that can be flooded temporarily to accommodate excess water without causing large damage or force lots of people to evacuate;
2. Strengthen dikes when necessary, for instance at locations where there is no room for widening rivers like in built up area’s such as the city of Rotterdam.
Currently, there are works going on at dozens of locations spread all over the country where extra room is created for rivers. These works are carried out under a national program that is called ‘Ruimte voor de Rivier’ (Room for the River).
For more information on this program you can take a look at the program’s website: http://www.ruimtevoorderivier.nl/english/


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