The intriguing thing about a conference chock full of present and former officers from the Army Corps of Engineers is that you get all the data you need, but you have to connect the dots yourself. At sessions focused on Hurricane Katrina during the Ecumenical Patriarch's Eighth Religion, Science and the Environment Symposium, Army Corps scientists and engineers, including Chief of Engineers Lt. General Robert Van Antwerp, gave the audience in New Orleans some sobering facts:
1. During the spring peak, the Mississippi River at New Orleans can handle only 1 million of the 3 million cubic feet/second of the water that comes down the river. At peak, two-thirds of the river finds another outlet to the Gulf.
2. 50 percent of the wetland-creating silt that once flowed down the river is today clogging up federal dams like Ft. Peck on the Upper Missouri. Not only is it eliminating more than half of the value of those dams as hydroelectric projects it is also making it virtually impossible for wetlands restoration to compensate for the gradual rise of sea level in south Louisiana.
3. During spring floods two years ago, if levees on the Upper Mississippi had not broken, the river would have crested at St. Louis -- more than 10 feet above the levee at the Gateway Arch -- and a second major American city would have been lost to flooding.
4. To protect the entire Gulf Coast from even routine hurricane damage is not possible. Nor is it possible to secure New Orleans against a worst-case storm.
What the Corps didn't (or wasn't allowed) to say, was what these facts mean:
1. The Mississippi River is seeking a shorter path to the sea, and New Orleans is no longer where the Big Muddy wants to end up. Effectively, the Atchafalaya to the west is where the river tries to go every spring. Eventually it will get there.
2. We need to manage the Upper Missouri dams to get the sediment out of them and back into the river. If we don't, we will soon have neither usable dams nor a defensible Southern Louisiana.
3. The entire levee system has given the Mississippi a case of atherosclerosis that causes it to flood now in even relatively ordinary water years. The engineers need to back off and dramatically expand the unleveed floodplain. Low-lying human habitations need to be moved to higher ground except in the biggest cities. Otherwise, if the levees protecting soybean fields hold, St. Louis dies. If cotton doesn't get flooded, New Orleans does.
4. The Gulf Coast needs a three-tiered system of protection, in which restored barrier islands protect coastal wetlands and cypress forests, coastal wetlands and cypress forests protect levees, and levees protect communities. Nothing else will work -- and this means that the Corps, the shipping community and the oil and gas industry all need to get out of the nature-destruction business and into the habitat-restoration business. Oil and gas operators, for instance, could do most of their work with hovercraft designed and manufactured in Louisiana but, because they aren't required to, they instead keep dredging channels that destroy wetlands and funnel storm surge right into New Orleans and other coastal communities like Houma.
You can imagine that if these were the unstated conclusions that flowed from the presentations made by the Army Corps of Engineers, then the papers delivered by scientists, who can be blunter about harsh realities of low-lying coastal areas in a global-warming world, were much harsher. We saw complex computer models that showed that, as we build up levees around New Orleans, unless we restore wetlands, all those levies do is shift the storm surge and flooding north into Mississippi.
Katrina was widely described as a "man-made disaster, not a natural one." And the voices of the religious leaders at the symposium were powerful -- but not powerful enough. Four years after Katrina, with a new Administration, things are better. But the necessary sea change in the way we protect the communities of the Gulf Coast still hasn't happened.
As General Van Antwerp said, it's not like we don't understand: "The river's going to do what the river's going to do." We ought to work with it, not against it. But changing our habits still comes too hard. When will we accept that only by protecting nature can we protect ourselves?