More on the "deadly funnel"-- MRGO

The MRGO channel to the south and the Gulf Intracoastal Waterway to the north create a funnel from the Lake Borgne area into the much smaller Industrial Canal in New Orleans.

That funnel effect, caused by the water channels and the levee systems built along the channels' banks, can direct a large amount of water into upper St. Bernard and New Orleans.
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"The only way to describe it is a deadly funnel, and this year it proved its deadliness," he said.

Short-term solutions involve finding a way to close off the intersection of the Gulf Intracoastal Waterway and the MRGO. Long term, he said, engineers should start looking at ways to build a curving structure that can block the funnel action before it affects the Lake Borgne area.

"Blocking one channel won't help. You have to block the throat," he said.

Computer models show that the funnel effect can increase the storm surge elevation by 20 to 40 percent.

Without that magnification, Katrina's storm surge wouldn't have flooded nearly as much of St. Bernard and wouldn't have caused the 9th Ward flooding, he said.

People in St. Bernard have been saying that the MRGO is dangerous for years. As usual, no one wanted to listen. Remember always that the Corp of Engineers first obligation is to navigation, not flood control Always has been.