Corps officials could announce historic reopening of spillway Thursday

Corps officials could announce historic reopening of spillway Thursday
FILE: An U.S. Army Corps of Engineers airboat operates in the Bonnet Carre Spillway (Source: John Snell)

NEW ORLEANS (WVUE) - Mississippi River water at the Carrollton guage is on the rise again, prompting the Army Corps of Engineers to call a news conference Thursday (May 9) to discuss a possible - and historic - reopening of the Bonnet Carre Spillway.

The rising river has created many new concerns. The spillway has been closed for more than a month now, but you would never know it by all the water rushing through the pins. The river is now 16.67 feet at the Carrollton gauge, and the Corps has been in flood fight mode for 195 days, the most since 1973.

“The river is changing, that’s not news, and we should pay close attention to what that means for us,” said Mark Davis with the Tulane Bywater Institute.

Though the level is rising, the real indicator of whether the spillway will be reopened is the river’s flow. Corps officials use one and a quarter million cubic feet per second as their trigger - something that occurred for this year’s previous opening Feb. 27 when the Carrolton guage read 16 feet.

“It’s how long the river has been up that is unusual,” said Davis.

All that high water is putting pressure on local river levees.

“Until the levees are loaded with high water, you don’t know what will or won’t be leaking,” said H.J. Bosworth with Levees.org.

Corps officials also try and limit spillway openings to minimize the impact of invasive freshwater species entering the Lake Pontchartrain basin. One of those impacts could be harming marine life. A number of dead dolphins have been showing up recently in coastal Louisiana and Mississippi.

St. Bernard Parish President Guy McInnis says they have documented 26 dolphin deaths in the past two months, and most of the animals had freshwater lesions. Though Louisiana Wildlife and Fisheries officials have not made a direct link to the influx of fresh river water, officials in coastal Mississippi have after conducting a number of dolphin necropsies.

“Trillions of gallons have come down from the Bonne Carre Spillway. That has changed the habitat, the food source and all sorts of changes for these animals,” said Moby Solangi with the Institute of Marine Mammal Studies in Mississippi.

Even those concerned about the fisheries say if an opening is meant to prevent flooding, it has to be done within the law.

“There are reports that dolphins and turtles might be affected. You can do it for public safety, but if you do it for less urgent reasons, then you may start bumping into other legal barriers that you must think through,” said Davis.

McInnis says he’s also concerned about the impact of fresh river water on oyster fisheries, and he’s asking the state to come up with more definitive answers.

We reached out to the state and were directed to the National Oceanic and Atmospheric Administration, or NOAA. So far, we have not heard back from them.

Copyright 2019 WVUE. All rights reserved.