[StBernard] N.O. flood potential now a click away

[Westley Annis]

N.O. flood potential now a click away

By JOE GYAN JR.
Advocate New Orleans bureau 
Published: Jun 29, 2007 - Page: 9B 

To confirm she made the right call in buying a home in New Orleans after
moving there a few months ago, Karen Durham-Aguilera used a preliminary
version of the Web-based maps recently unveiled by the U.S. Army Corps of
Engineers to assess her risk of flooding from a “100-year’’ hurricane.

So who is Karen Durham-Aguilera?

She is the civilian director of the corps’ Task Force Hope, which is
overseeing the agency’s $5.7 billion hurricane protection system work in New
Orleans and southeast Louisiana in the aftermath of Hurricane Katrina.

With the corps’ long-anticipated release of the flood maps, residents in
Orleans, Jefferson, St. Bernard, Plaquemines and St. Charles parishes can do
what Durham-Aguilera did.

They can enter their addresses into a Google Earth program on a Web site —
http://nolarisk.usace.army.mil — to see where flooding can be expected, and
to what depths, in various parts of metropolitan New Orleans from a
hurricane that has a 1-in-100 chance of hitting the area each year.

During a demonstration of the Web-based flood maps at the corps’ New Orleans
District office June 20, a television cameraman’s eastern New Orleans
address that flooded during Katrina was plugged into the system.

When the results showed his Yardley Road address off Interstate 10 and
Bullard Avenue can expect no change in flooding, or that he could again
expect to be hit by 4 to 6 feet of flood water if a major hurricane strikes,
the cameraman simply said, “Time to move.’’

About 80 percent of New Orleans suffered catastrophic flooding during
Katrina, including eastern New Orleans, the Lower 9th Ward, Lakeview and
Gentilly. Neighboring St. Ber-nard Parish was completely inundated.

In addition to flooding, the “risk and reliability’’ analysis performed for
the corps by a 150-member team of scientists and engineers — the Interagency
Performance Evaluation Task Force — also projects loss of life and property
that could be expected to occur as a result of flooding.

In parts of eastern New Orleans, where hurricane protection levees have been
elevated to 20 feet along the Gulf Intracoastal Waterway since Katrina,
corps and task force officials said the improvements have decreased risk
only slightly.

They said the ability of those levees to withstand overtopping is
questionable because no structures are in place to prevent storm surge from
heading down the Intracoastal Waterway to the Industrial Canal. The corps
hopes to lessen that risk next year with the construction of a temporary
gate on the Intracoastal Waterway near the Paris Road bridge to Chalmette
and other temporary measures.

Only a 2-foot reduction in flooding and 4 percent drop in property losses
are anticipated in the Lower 9th Ward and in Arabi in upper St. Bernard
because of improvements made since Katrina, officials said. Some improvement
is expected in Chalmette, including a 2-foot drop in flooding and 8 percent
reduction in property losses, but more progress will require raising levees
and floodwalls as high as 28 feet along the Mississippi River Gulf Outlet
and the completion of gates on the channel to keep surge out of the
Intracoastal Waterway.

In Lakeview and City Park, a marked reduction in potential flooding is
expected because new floodgates on the 17th Street, London Avenue and
Orleans Avenue canals will block surge entering from Lake Pontchartrain.
Officials project an average 5‰-foot reduction in flooding, compared with
estimates of flooding from the same kind of storm before August 2005, and a
32 percent decrease in property losses.

The corps said its intent is not to “scare’’ anyone with the information,
but to share it so all can be better informed and prepared.

Joe Gyan Jr. is The Advocate’s New Orleans bureau chief.