Flash-Flood Fix for the 21st Century: Mechanized Sandbags

That was the nightmare at One Kensington Gate, a 96-unit co-op in Great Neck, Long Island, built on low ground. A recent flood heavily damaged 18 most late-model cars, and cost the co-op between $15,000 and $20,000 in pumping and cleaning costs. And the floods are becoming more frequent: Board president Ira Litt counts two in two years, as opposed to only eight since he became a tenant-shareholder in 1973. He blames the increase on Nassau County's aging and inadequate network of storm drains that don't pull water underground but instead allow it to cascade into the co-op's upper and lower garages "like a waterfall, two- to four-feet high. Whenever there's a major storm," Litt says, "normally we're putting sandbags out — but some are flash floods and you can't do anything about [them]."

Shareholders didn't like the perennial flooding dragging down the value of their apartments, and the co-op's budget was being battered, with non-resident parkers starting to reconsider their $200-a-month parking fees in the 100-space garage.

That's when former board member Mort Hans, a retired engineer, found a flood-control product called FloodBreak, made by a company in Splendora, Texas. Hans wanted a solution that would outperform sandbags but would not involve the construction of a new, higher street. It looked like FloodBreak — which erects a gate to stop the flow of floodwaters automatically, without the need for human intervention and without utilizing an external power source — might do the trick.

FloodBreak (seen at right) amounts to a hollow, extremely strong aluminum wafer that lies flat between walls leading to the entrance of a property. Mounted within the aluminum wafer is a grating with rods that extend out and down when floodwaters cause the entire assembly to rise, locking it into place and creating a secure barrier, sealing the entryway.

"If you don't have a flood condition," says property manager Michael Einsidler, a principal at Einsidler Management and Northeast representative for FloodBreak, "the water will flow out of the grate, but it won't push the gate up. If the water has no place to go, it will pick up the gate." He notes that in order for FloodBreak to work, it must be positioned between walls high enough to contain floodwaters.

The location of the device is crucial, because the surrounding topography must be carefully mapped so that water doesn't find a way around the barrier. The board of One Kensington Gate found itself paying not only for an engineer to work out exactly how to anchor the device in the driveway, but for a geologist to map the flood plain on which the building sits. The complete cost, once the gate is fully installed and operational, will be about $125,000, which is being drawn from the co-op's reserves.

Adapted from Habitat March 2008. For the complete article and more, join our Archive >>