"With New Orleans in ruins, hydrological engineers are looking to new technologies to bolster aging earthen levee systems," Defense Tech pal John Gartner reports in today's Wired News.
The Army is currently testing products that can temporarily raise the height of levees to determine if they can be assembled faster than the usual defense of filling and stacking sandbags.
The Rapid Deployment Flood Wall from Geocell Systems is a series of interlocking sections of plastic that are filled at the scene with sand or soil and can be layered as high as necessary.
The Hesco wall is a metal basket with fabric sides that is filled with soil. Hesco walls can be folded flat for easy shipment, according to Hesco Bastion director of operations Jared Lyons, who said his products are being used to protect against floodwaters in Texas and Florida.
The Portadam system is a series of metal rods that are bolted together and do not have to be filled with soil...
But so far, at least, the problem of holding back floodwaters has progressed little beyond the ancient and time-consuming technique of piling on more dirt.
THERE'S MORE: "It occurred to me that there might be a way to use superabsorbent polymers to form self-building flood protection barriers or to slow the flow through a breach," says reader KP, a CalTech Ph.D. candidate in engineering. "Sure enough, a quick search reveals a couple of solutions already out there."
http://www.finetech.bz/pages/4/page4.html?refresh=1092815632729
http://www.protectionconnect.com/sandless.html
As best I can tell the mechanism of swelling is osmotic pressure, so these bags would not perform as well for seawater as they would for fresh water. Also, its not clear how well the bag contents would resist deformation due to water pressure. Neverthless, reducing the mass logistics of a flood wall by a factor 10,100, or 1000 is a big deal, and I expect that an imaginative individual could find a way to make it work.
