03/21/2017

We live in a world of constant change. Everything we do changes the world that existed the moment before we did it. That includes flood plains, which people across south Louisiana have learned a good bit about over the past year as a result of flooding that has affected us.

The recorded rainfall across south Louisiana and Mississippi on the first day of the Great August Flood of 2016.
The big one was the August flood of last year that wreaked havoc from southwest Louisiana into southeast Mississippi. We quickly learned that we were not prepared to deal with the effects of years of rapid growth and decades of thinking about flood control in terms of keeping water in rivers.

The hardest hit areas in that flood were the areas that had experienced the most growth. In hindsight, it seems so logical. After all, early settlers and development in regions took place on the high ground, particularly in low-lying southwest Louisiana. Development that followed was toward those low areas where those before them had opted not to settle or build.

When the deluge struck in August, we learned hard lessons about hydrology and construction. Water not only finds its level, it finds its way. It is indifferent to what may stand in the way of it getting there.

Flood protection strategies that focused on keeping river water out of communities were revealed to be traps that kept rain water in those same communities, particularly in the Baton Rouge region. People whose homes and/or businesses were hit by the floods in Louisiana last year (the Shreveport/Bossier area was hit by Red River flooding in the first part of the year and the Monroe area was hit by flood producing storms in the spring) now have an idea of the ordeal that those driven from their homes by Katrina and Rita went through just over a decade ago.

Flooding in northwest Louisiana, spring 2016.
This is not the end of it.

As the atmosphere continues to warm, the air holds more humidity. The seas are warming, as well, meaning more moisture is evaporating into the atmosphere. It’s a recipe for more severe weather like we experience in 2016.

On the other hand, some of the post-flood recovery has involved repeating the very mistakes that made the floods so devastating. Since the floods in the Lafayette area, more ‘slab on grade’ homes have sprung up many in or next to subdivisions that flooded last year.

Flooding in south Louisiana, August 2016.
Just because an area did not flood last year does not mean that it won’t flood next year. The basic rule of flood plains is that everything built in them — from parking lots to homes to commercial developments — changes them because each structure or project alters the ability of the ground to absorb water. And when wanter can’t get into the ground, it’s going to move to a point where it can.

For decades the efforts in south Louisiana has been to quickly move the water out. As we learned last year, sometimes there is too much water to move out. We also learned that there is nothing you can do to speed the removal of the water when the ground is flat and saturated. Water from the Vermilion River in Lafayette stayed in some homes and subdivisions for weeks after the rains stopped.

Grasshopper Mendoza

Steve Picou
Steve Picou and Grasshopper Mendoza have first-hand experience dealing with the impact of water. Their New Orleans home flooded after the federal levees failed in the wake of Hurricane Katrina. They’ve been part of the great conversations that sprang up in New Orleans about how to rethink the city’s relationship with water. It’s a conversation that should be taking place all across south Louisiana as we confront the elements of climate change — warming temperatures, sea level rise, land subsidence, increased severity of severe storms.

In the face of this existential threat to life as we have known it in south Louisiana, as Steve says in the interview, “we must must adapt or move, or both.” The status quo is not an option. It’s already gone.

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Thanks to Matt Roberts, AOC’s Community Programming Director for help locating the music used in this segment.

Guest UserMarch 21, 2017Comment