Flood Control Goes Greek
Saturday, November 24, 2007
A working-class community in Prince George's County that has flooded four times in the past four years has put a technology more than 2,000 years old to work in a new $6 million pumping station that residents hope will keep their little town dry.[an error occurred while processing this directive]
The design, known as an Archimedes screw for the 3rd century B.C. Greek mathematician credited with conceiving it, employs a massive, slowly turning screw to lift a huge quantity of water up a short distance. The new station in Edmonston uses three of the screws to raise water the 20 feet necessary to get it up and out of the town and into a levee system that runs along the Anacostia River.
The technology has been used to shore up the dikes and levies of the low-lying Netherlands for years but is relatively uncommon in the United States. An engineering consultant working on the project thinks the Edmonston's station is probably the largest such Archimedes screw pump on the East Coast and one of the most powerful in the nation, capable of lifting 250 million gallons of water a day.
Edmonston, which borders Hyattsville and Bladensburg, is essentially at the bottom of a geological basin along branches of the Anacostia. Levees built in the 1950s by the U.S. Army Corps of Engineers keep the swelling river out of the town and neighboring communities. But they also form a barrier that prevents stormwater that pools in the town from flowing out and into the river.
A pumping station was built in Edmonston when the levee was constructed, but it was small even when it was first unveiled, designed to flush the town of water from the kind of flooding that might occur every two years. Anything more, and Edmonston residents were out of luck.
Since then, the Edmonston section of Prince George's has become more urban, covered with acres of parking lots and flat-roofed warehouses that collect water -- which have channeled more and more stormwater into the 1,500-resident town.
The pump has also aged. It's a traditional design for providing flood control, with a small rotating impeller that spins quickly, lifting water up a vertical pipe. But because the fan spins so fast, it can short out or get clogged with branches. It has also had a tendency to freeze up when the water flowing in becomes icy.
In December 2003, a hard, fast rain hit melting snow and swamped the town. "Town hall was full of people yelling and yelling," Mayor Adam Ortiz said.
Edmonston flooded again July 4, 2005, and in October 2005.
When the water rose once more in 2006, 86-year-old Mary Temarantz declared she'd had enough. The water poured in her windows and doors so quickly that she had to be evacuated by boat. After more than four decades in Edmonston, she decided to move.
"When I get that house in order, I'm getting out of there," Temarantz said shortly after the flood.
But, impressed with Archimedes and his screw, she has decided to stay put.