Environmental Engineering Reference
In-Depth Information
only a few of eight basic steps—such as getting flood insurance or putting together a
disaster evacuation plan—to protect themselves.
In the spring of 2007, New York was deluged in a series of vicious stormbursts; one,
in April, saw seven inches of rain fall in hours, the biggest precipitation measured there
since 1882. If coupled with a nor'easter storm or a hurricane,
extreme looding could
hit
the city once every forty-three years by the 2020s, once every nineteen years by the
2050s, and once every four years by the 2080s, the DEP predicts.
To help absorb more precipitation, New York has begun to restore wetlands, promote
green roofs and bigger tree pits, and build porous “green-streets,” which allow storm-
water runoff to filter into the ground. But these are incremental steps. The city relies on
an old, already overburdened sewer system and a few catch basins and inflatable flood
barriers.
Its lood maps
,
which show areas prone to hazardous flooding, are outdated,
and the city has no major flood defenses, large catchments, or storm-surge barriers.
Hurricane Katrina no one would listen to a bunch of academics,” said Dr. Malcolm
Bowman, a professor of physical oceanography at the State University of New York at
Stony Brook. “Now a few people in the city government are returning my calls.” Hur-
ricane Katrina, he said, was “a warning to other cities of what kind of disasters could be
in store. A temperature shift will change our world, and we'd better be prepared for it.”
With higher sea levels, he said, weak storms of the future will be as destructive as severe
storms are today.
To defend against the catastrophic flooding of New York City, Bowman and his col-
leagues at Stony Brook's Storm Surge Research Group have proposed building three
enormous storm barriers, thirty-five feet high and up to a mile long, to provide “a circle
of protection” from surging ocean waves.
In England, the Thames River is outfitted with giant swinging floodgates; in Italy, the
Venice lagoon is defended by inflatable gates that rise from the seafloor; in Holland,
massive swinging barriers protect Rotterdam from the North Sea.
The enormous gates that Bowman suggests for New York have not been designed yet
but are likely to be swinging metal structures, with navigation locks to allow boats and
water to flow through. They would be placed at the Verrazano Narrows (the gateway
to New York Harbor), the upper reaches of the East River (where it joins Long Island
Sound), and across the Arthur Kill (a stretch of water between Staten Island and New
Jersey).
A similar scheme, designed by
Halcrow Group Ltd.
,
a British infrastructure con-
sulting firm, calls for a single five-mile-long barrier to be built between Sandy Hook,
New Jersey, and the Rockaway Peninsula, in Queens. A third floodgate plan, from New
York-based engineers
Parsons Brinckerhof
, envisions a wall that lies flat on the bed of
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