The rising Mississippi River crested Monday in Baton Rouge at a slightly lower than expected level of 43.3 feet, but the high water is expected to stick around for a while.
Forecasting how long the river will remain above flood stage is difficult because there are several factors that come into play, from the opening of floodgates at the Bonnet Carre spillway near New Orleans to the amount of water that has been stored in parts of the flood plain.
“All that water that went into storage needs to come out,” said W. Scott Lincoln, senior hydrologist with the National Weather Service Lower Mississippi River Forecast Center.
According to long-range forecasts, water levels at Baton Rouge aren’t expected to get below 43 feet until Saturday. The river will continue to slowly drop over the coming weeks until it’s below flood stage of 35 feet in Baton Rouge sometime during the second week of February.
“The good news is we’re basically cresting today,” Lincoln said. That crest level will continue for a few days, he said, but “we are about over the hump.”
A new long-range forecast from the National Weather Service Lower Mississippi River Forecast Center will be available on Wednesday with updated information. As more information arrives, forecasters will have more precise predictions of water levels.
“Usually, when it gets this high, it doesn’t fall that fast,” Lincoln said. “So much of the flood plain is just filled with water. There’s lots of water that has to work its way out.”
The U.S. Army Corps of Engineers opened the Bonnet Carre spillway on Jan. 10, and as of Monday, 210 of the 350 bays were open.
Levee officials will continue watching for any damage caused by the high water and remain vigilant about keeping vehicles off the levees.
Monica Salins, Pontchartrain Levee District executive director, said patrols and cameras of the levees will remain as the water starts to fall to make sure people stay off the levees. Of special concern is the temptation that muddy ground on the river side of the levee can have for people who want to run four-wheelers or trucks.
So far, she said recently, people have been good about keeping vehicles off the levees to minimize any potential for damage.
“Everyone’s been so cooperative and so understanding,” she said recently.
The Pontchartrain Levee District monitors the Mississippi River levees starting just north of LSU and running south through the six parishes of East Baton Rouge, Iberville, Ascension, St. James, St. John the Baptist and St. Charles.
The city-parish has authority over the approximately 1.5 miles that run through downtown.
On the Atchafalaya River, the river at Morgan City is still rising and reached 7.8 feet Monday afternoon. The river was expected to continue to rise to a crest of 8 feet by Saturday morning, about a half foot lower than was expected last week.
Follow Amy Wold on Twitter, @awold10.