"I wanted to be a rain salesman,"

First line of a poem by John Engman called Work in his collection entitled Temporary Help (1983). We are a ways from the rain production business, but we are definitely in the flood prevention and control occupation. With 100,000 miles of levees in the United States, flooding starts and stops with the condition and backup plans associated with our levee system. Levees fail for many reasons, not all of them associated with storms such as Hurricane Katrina - - the sheer size of the system makes periodic inspections an impossible task. This is why the backup plan is so important.

A slew of new technologies have been recently released to help with the backup part and replace the ancient method of throwing sand bags and rocks on and into levee breaches. They have two elements is common - - they all use water itself to help stem the flood and they all have clever acronyms.

The first is called PLUG - - for Portable Lightweight Ubiquitous Gasket. The PLUG is a sausage-shaped balloon made out of polyester and PVC. When dropped into a river by helicopter, PLUG’s pumps switch on automatically and begin forcing water into the balloon through a value. The air thus displaced is expelled through a second value until the device is 80% full, at which point the pumps shut themselves down. Filled thus far, PLUG is still buoyant and will float wherever the current carries it. If it has been dropped in the right place that will be towards the breach it is designed to fill. If all goes well - - the failed levee should have a PLUG, so to speak.

The second technology is called REPEL – for Rapidly Emplaced Protection for Earthen Levees. It has the same material as the PLUG. REPEL is laid out flat on a levee that is in danger of being overtopped - - with a series of tubes that sit on top of it and can be pumped full of water in a manner similar to PLUG. The weight of the tubes holds the protective layer in place, while the gaps between the tubes permit the overspill to escape. Some flooding from the overspill results - - but not as much as if the spill were allowed to erode and destroy the levee itself.

The third technology is called REHAB - - for Rapidly Emplaced Hydraulic Arch Barrier, made from the same material as the over two technologies. The REHAB system can be put in place around a plugged breach to keep it sealed and dry once the PLUG has been removed. First, the arch is filled with air and floated to the desired location. Then, once it is in place, it is partly flooded and allowed to sink to the riverbed around the breach, making a tight seal. This done, a second set of pumps evacuates the gap between the arch and the PLUG, allowing workers access to the site.