Every year in the Fundamentals of Environmental Planning we talk about the problems with building in floodplains, and every year we seem to see a new mix of surprise problems and completely avoidable disasters. This year we have the flooding in Iowa (they call it "record" levels), which has received remarkable coverage by the Des Moines Register. They have published a map of the floodplains (above) that shows exactly what should have been anticipated (actually, worse things should be anticipated since the 100 year floodplains are rarely updated to reflect changes in the physical landscape). Their photo galleries and videos have been remarkable.
Iowa City is a lovely old city built along a river, and older buildings in the floodplains are simply part of the deal. Balancing historic preservation with environmental preparedness often means finding ways to perpetuate a campus like the University of Iowa's, knowing full well that its entire core is in the 100 year floodplain. Again, that's part of the deal. But new buildings in these areas are a baffling problem that are both costly and sometimes dangerous. Just take a look at this picture of the new Art Building at Iowa. When Des Moines built its baseball stadium in the confluence of two rivers, did they not know that it was a risky idea?
While some of this is simply natural - rivers flood, that's what they do - our land use patterns have exacerbated the problems in multiple ways. We've destroyed the natural wetlands upstream that could have absorbed more of this water. We've created more impervious surface, causing flashier flooding downstream. And, most unforgivably, we've built new expensive buildings in places where they are predictably at risk. To be clear, these are complex events with all sorts of contributing factors and problems, and flooding will always happen and will often come with some associated cost. But some of the problems are inexcusable and should have been avoided.
Lives are being shattered if not lost, and some degree of blame falls squarely on planners and designers that have encouraged this pattern of development. Perhaps the most upsetting part is that (like New Orleans) some of the students, homeowners, and other residents placed their trust in the agencies that allowed these patterns to unfold. Planners and designers keep letting the public down in ways that undermine the public trust. Even worse, the notion that these groups are watching out for the landscape itself is not in any way supported by these outcomes.
Here in the New Brunswick area we saw the "unpredictable" storm event of Hurricane Floyd in 1999 which created historic flooding. What could we do? It was unprecedented. Surely it would be another 100 or 500 years before we saw that again. Then, a few years later we had a nasty Nor'easter which matched or surpassed the historic flood levels. Maybe we should all learn to study odds a little better.