Sinking Louisiana: Modeling For Change

Jun 14, 2019

Louisiana’s Coastal Master Plan is the state’s guide for restoring its disappearing coastline and defending cities from rising seas. It includes things like levees and rebuilding marshes. But how does the state decide where to build projects? How does it decide what kind of project to build? And how is climate change considered?

All month long, WWNO is teaming up with Louisiana Public Broadcasting to bring you a special series called Sinking Louisiana. This week, WWNO’s Travis Lux talks talks with Bren Haase, Executive Director of the state’s Coastal Protection and Restoration Authority (CPRA), about how the state makes big decisions that impact lots of people. They spoke at the CPRA headquarters in Baton Rouge.

You can listen to the radio version of the interview here:

You can also watch an extended video version of the interview here:

The following transcript of the radio interview has been edited for clarity:

Q: I want to talk about how the state makes decisions for coastal projects. How does the state decide what to put where? How do you decide to put a levee over here, a marsh over there, or a barrier island over here?

It really starts with the universe of projects, honestly. And which projects are proposed. As we’re developing the Master Plan, we put a public call out for projects. People have different ideas -- maybe they want a levee here or a marsh there. We then go through a pretty rigorous evaluation process of each of those projects.

It really comes down to two basic things: how well will a risk reduction project reduce risk in terms of storm surge flooding for our coast, and how well would a marsh creation project or ecosystem restoration project result in more land for coastal Louisiana for the future.

Q: Next door [to the CPRA headquarters] there’s a big building called the Center for River Studies. It’s got a huge model of the lower Mississippi River, the size of two basketball courts. It was really expensive -- more than $2 million. What is that going to be used for? Is that going to be used to help make decisions about where to put projects?

There’s really two main purposes for that building. One, it’s a great outreach and education tool about the issues facing coastal Louisiana. Two, it’s also a technical tool for evaluating projects. That model over there is a small scale, scaled-down version of the lower Mississippi -- essentially from Donaldsonville all the way to the Gulf of Mexico. In that river we can control water levels, flow, and mimic the actual flow in the real river.

And probably most importantly, there’s some simulated sediment particles that we can inject into the model -- into the river -- and see how that sediment reacts to things like a potential diversion project, different dredging schemes in the river, that kind of thing. It’s another tool that we can use to understand how managing the river in certain ways can help preserve the coast and help rebuild our coastal wetlands.

Q: Why do we need a physical model anyways? The Master Plan is full of all these maps and pictures of what the landscape will look like, so we’re clearly capable of visually projecting what the landscape might look like without a physical model. It’s cool and swanky, but why do we need it?

It is cool, it is swanky, but there is some real technical need for it. It’s another way of confirming what we see in nature and what we see coming out of those computer models. It’s always good to have two answers to the same question -- or redundant answers -- to the same question. That’s really kind of the theory here.

Q: Looking at the master plan, are there any specific projects or approaches to the plan that are in response to climate change? Or that are meant to address climate change in particular?

I would say the whole plan is an adaptation plan. And that adaptation is in response to climate change. I don't think there’s any one project in particular that is designed to deal with climate change issues in Louisiana. I think the whole suite of projects and the whole plan really is an adaptation plan for a changing coast. Some of that change of course is going to be the result of climate change.

You can view extended interviews from the Sinking Louisiana series online at LPB.org/sinking.

Support for the Coastal Desk comes from the Greater New Orleans Foundation, the Walton Family Foundation, and local listeners.