The Economist reports on some of these new technologies and techniques, including some that use the power of water itself to prevent levee breaches.
"The largest of the new devices is designed to block deep breaches. The Portable Lightweight Ubiquitous Gasket (PLUG) is a sausage-shaped balloon made of polyester and PVC, and fitted with motorised pumps. When dropped into a river (usually by helicopter), PLUG's pumps switch on automatically and begin forcing water into the balloon through a valve. The air thus displaced is expelled through a second valve until the device is 80% full, at which point the pumps shut themselves down."