More On MRGO

After my last post, I did a little research on the Mississippi River Gulf Outlet (MRGO as they call it down on the gulf). It’s a shortcut for river traffic from the Gulf of Mexico into the port of New Orleans which was completed in 1965. It allows for quicker traffic to New Orleans because it allows traffic to bypass the twists and turns of the Mississippi River, and it also allows larger ocean going vessels into the port. The levees along the canal were breeched during Hurricane Katrina at numerous locations causing extensive flooding in St Bernard Parish.

It turns out this particular canal has a bit of controversy to go along with it. Ever since it was first built, the MRGO has been the bane of environmentalists by contributing to the loss of thousands of acres of coastal marsh. But environmental impacts took the back burner after Katrina. Apparently LSU’s Hurricane Center did some modeling of Katrina and determined that the MRGO made the initial storm surge worse by 20% (about 3 ft) and increased the wave velocity from 3 feet per second to 8 feet per second. They contend this is why the levees failed so spectacularly rather than simply being overtopped. The Corps of Engineers contends that the levees would have failed like that anyway. (Which is an interesting contention in itself since they built the levees in the first place.)

There has been a drive to close the canal for years. Even the Corps of Engineers got on board and has been looking at the best way to close it since 1998. The local citizens of St. Bernard Parish certainly are ready to close it down. To quote the New Orleans Times-Picayune:

"It's over," declared Parish Council Chairman Joey DiFatta. "If the people of St. Bernard saw the Corps of Engineers out there dredging again, there would be some dead people on those dredges. Everybody in St. Bernard knows someone who died in that storm, and there are some very passionate feelings about that."

It’s an interesting study on the power of mother nature and one of her favorite mediums, water. The canal was originally 650 feet wide and is now approximately 1,500. It has silted in from 36 feet deep to as little as 21 feet in places since Katrina. That’s pretty typical of a river in flat open country like coastal Louisiana.

Rivers are dynamic and very active in this type of environment and they tend toward shallow, wide, and winding while humans prefer them deep, narrow, and straight. That’s the eternal battle between the U.S. Army Corps of Engineers and essentially every river in the country ever used for navigation (see also west Tennessee).