A group of south Louisiana fishers and charterboat captains have complained that the state's master plan for the coast puts too much emphasis on sediment diversions. These projects would funnel Mississippi River sediment into targeted areas to help rebuild dying marsh. There are good arguments for diversions. But diversions will change the way we use the coast, and change isn't easy. Hence the diversion opponents who have taken their arguments public.
How to fairly convey the costs and benefits of diversions? First rule: don't use debate vocabulary if you don't want to debate. My attempt at a fact sheet tries to avoid false equivalencies, "myth vs. fact" formats, and other score keeping gambits. A focus on common sense questions makes a more credible case.
Sediment Diversions & Louisiana's Coast
You've probably heard that river diversions can rebuild the dying wetlands our coastal communities depend on. Most scientists agree, as do most Louisiana residents. Others say diversions aren't the answer. Having trouble figuring it out? Read on.
Are sediment diversions a good idea? Thirty years of research says that diversions of Mississippi River sediment can build healthy wetlands in south Louisiana. We see the proof at Wax Lake, where a diversion of the river is building land right now. People who know the coast have long said that we can save our communities if we use the river right. In fact, diversions are widely seen as the only way to secure our coast's long-term future.
Do we know how to do this? Sediment diversions are big projects, and we will have to build in room to learn some things as we go. But we have decades of research from Louisiana and around the world to help us, so we won't be starting from scratch. We have another advantage as well. Modern diversions seek to safely copy the natural process that built our coast in the first place, so we'll have Mother Nature on our side.
Are there other alternatives? Dredging sediment and delivering it with pipelines works for areas that are far away from sediment rich rivers. But the land created doesn't last as long or support as many plant, animal, and fish species as land created by diversions. Bottom line: we need to use both diversions and pipelines—not one or the other.
How big will diversions be? Diversions have to be big enough to build marsh, yet manageable enough to coexist with our communities. To strike the right balance, diversions would only run at their maximum flows during major floods, like the one that occurred in 2011. This will help bring in the sediment our coast desperately needs. The rest of the time, diversions would run at smaller flows or be turned off.
What about fisheries? Diversions will move saltwater fisheries further south, where they would normally be if our coast weren't losing land so fast. Having saltwater fisheries as far inland as they are today is good for fishers, because it cuts their travel time. For the rest of us, having salt water in upper Barataria and other inland areas isn't good because it's proof that our coast is washing away.
How can we help fishers make the transition? The new diversions will not be on line for at least five to ten years. That's enough time for the state and federal governments to work with affected fishers to help them adjust. If we don't get sediment diversions built in the meantime, the wetlands will die and we'll all lose—fishers, farmers, families—the two million residents who call south Louisiana home.