The Mississippi River has been at flood stage for months. Levees and spillways keep most homes and businesses safe and dry from the flood waters, but the high water still creates headaches for levee districts and industries like oil and gas, and fisheries.
This week on the Coastal News Roundup, WWNO coastal reporter Travis Lux went to find out how the river creates problems we can’t always see. WWNO’s Tegan Wendland got the details.
The following transcript has been lightly edited:
TW: The river can be kind of out of sight, out of mind. We know it’s there, but unless we’re crossing it on a bridge we don’t really know what it’s up to. You went to find out some of the ways a high river affects the state
TL: Yeah, I think there are kind of three categories of impacts: government, economics, and the environment.
TW: Start with government. How do the state, local parishes, and levee districts deal with a high river.
TL: For starters, there’s lots of dredging. When the river gets high it brings a lot of sediment and the Army Corps steps up its dredging to keep the river clear. Then there are levees which need to be inspected. The Corps and local levee districts are out there inspecting them every day right now.
TW: They’re looking for leaks and seeps -- anything that would compromise the strength of the levees.
TL: Exactly. Crews are driving up and down the levee looking for leaks, seepage, barges that are parked incorrectly on the river. Or, maybe someone is digging too close to levee.
TW: Which is why army corps limits construction and development anywhere near the levee when the river is high.
TL: You basically can’t do any digging within 1500 feet of the river. That may not seem like a big deal, but can cause headaches for certain projects. The City of New Orleans actually has a number of projects on hold because of the high river. A lot of them are road paving projects -- but the big one is the Bourbon Street resurfacing project which is on pause until the river drops a few more feet.
TW: Then of course there’s the economic impacts. You talked to someone with the Louisiana Mid-Continent Oil and Gas Association (LMOGA) about how high water affects shipping and oil production.
TL: I talked to LMOGA President Tyler Gray. He represents oil and gas interests in the state, including a lot of the refineries between Baton Rouge and New Orleans.
GRAY: A refinery operates 24 hours a day, seven days a week. So when you have these delays or changes in receiving a product -- or exporting or moving a product out through the Mississippi River -- delays that cause the cutting of rates. Which affect the refinery’s bottom line.
TL: Ships slow down, so the refineries slow down, and that means less money. Less money, too, for shipping interests and ports.
TW: And then there are the environmental effects of a high river. What’s happening in the lake - and in the marshes and bays, especially when spillways are opened and some of that fresh Mississippi River water is diverted?
TL: For one, you can get algae blooms in Lake Pontchartrain. All that fresh water has nutrients that can cause algae to grow under the right circumstances. When the algae dies, it sucks oxygen out of the water which can kill fish.
TW: What about fisheries? Shrimp and oysters -- they like water with some salt in it. All of this fresh river water must change their habitats.
TL: I talked about this with Patrick Banks, Assistant Secretary of the Louisiana Department of Wildlife and Fisheries. He says it’s not a huge for most species.
BANKS: For the most part our fisheries go through a period of displacement where they simply move to more conducive areas. And that typically works just fine for the vast majority of our fisheries. The exception of course is oysters.
TL: Oysters can only survive fresh water for a certain period of time -- or else they die. That’s complicated by the fact that they can’t move as adults, so there’s been an effort to relocate many of them.
TW: The water has been high for a long time this year. It’s the third time in four years the Corps has opened Bonnet Carre Spillway to avoid flooding the city. We could continue to see high water events like this in coming years, and officials may need to take that into consideration in future.
TL: Yep, but that’s another story.
Support for the Coastal Desk comes from the Walton Family Foundation, the Greater New Orleans Foundation, the Foundation for Louisiana, and local listeners.