Editor's note: This post has been updated, after it was originally written prior to hurricane Isaac's landfall in New Orleans. Watch "Starting Point" at 7am on CNN for the latest on Isaac's track.
By "Starting Point" anchor Soledad O'Brien
The concrete is so clean on the Inner Harbor Navigation Canal/Surge Barrier that it looks like they poured it yesterday. But the roiling clouds above it made it clear why it's completion in May was critical. It's about to face its first test.
They call it "the wall." It's a two mile stretch of concrete that's designed to keep the waters from the Gulf of Mexico from flooding into Lake Borgne then inundating New Orleans neighborhoods like the Lower Ninth Ward. A surge that took that same path destroyed homes and left a trail of dead during Hurricane Katrina in 2005.
This massive post-Katrina effort by the Army Corps of Engineers with three 150' gates began in 2009. On Tuesday, the two doors were closed for the first time in anticipation of Hurricane Isaac.
"Last time the surge went into Lake Bourne and into the heart of the city," Col. Edward Fleming of the US Army Corps of Engineers tells me. "This wall is built to 26 feet high and we expect to see surge 8 to 10, maybe 15 feet."