In areas that will experience backwater flooding, it’s estimated that an additional 22,500 people and 11,000 structures could be affected, Jindal said.
Although these are rough estimates, Jindal said, they should give parish officials and residents a better idea of the response needed.
At the same time, it’s expected the Morganza Spillway opening could reduce high water flowing past Baton Rouge by 1.5 feet from the expected crest of 47.5 feet, said Tom Holden, deputy district engineer for programs and project management with the U.S. Army Corps of Engineers.
The trigger for opening the Morganza Spillway is when 1.5 million cubic feet per second of water is flowing in the Mississippi River by the Red River Landing. Right now, that flow is 1.36 million cubic feet per second, Jindal said.
“We expect to reach that trigger on Saturday or Sunday,” Jindal said, adding that a decision on opening the spillway could be made from Saturday to Tuesday.
Jindal repeated that people should not wait to prepare.
“There’s no reason for folks to delay,” Jindal said.
Corps computer models show that when the spillway is opened, about 3 million acres within the Atchafalaya River basin will be flooded. Of that land, Jindal said, about 18,000 acres are used for agriculture.
On Tuesday, the state began pushing the U.S. Department of Agriculture to officially classify the expected opening of the Morganza Spillway as a “natural disaster,” clearing the way for crop insurance payments.
The USDA crop insurance program generally does not pay for damage from “manmade” disasters.
Louisiana Agriculture and Forestry Commissioner Mike Strain sent a letter on Tuesday to Louisiana’s congressional delegation urging the group to contact USDA officials “to make them aware of the impending crisis.”
Strain said damage should be considered the result of a natural disaster, because flooding will occur regardless of whether the spillway is opened and because failure to open the spillway could lead to more-severe flooding down river.
Farmers in the Morganza Spillway are working to the last minute to harvest what they can, mainly wheat at this time of year, Strain said.
In East Baton Rouge Parish, city-parish officials are continuing to prepare the levees, residents, businesses and industries for the high water that’s coming down the Mississippi River.
The levees have been surveyed to get more-detailed heights, sandbags are being placed in low areas.
Starting today, Department of Public Works employees will install temporary water-filled bladders that will be anchored in place to provide an additional 18 inches of protection, said Jim Ferguson, chief engineer for DPW.
Although the current river forecast is for the water to get as high as 47.5 feet, the levees are currently between 47 and 51 feet along the two-mile section the city-parish has authority over, he said.
The levees are being inspected every day and by Saturday the inspections will be done twice a day, Ferguson said.
Vehicles are prohibited on or near the levees, and people are asked to avoid the levees for sightseeing. If people do walk up to see the water, they’re asked to avoid walking on the grass and instead use areas that are already paved, he said.
“Foot traffic, as ridiculous as it sounds, could cause problems,” Ferguson said.
There will be high water on the levees for an extended period of time and any indentation — even from foot traffic — could create weak points, he said.
“We have cameras set up on the levees, some you can see and some you can’t,” Ferguson said.
As the city-parish prepares, it’s also important for parish residents to prepare as well, said JoAnne Moreau, director of the Mayor’s Office of Homeland Security and Emergency Preparedness.
“Basically, this is a very slow-moving hurricane,” she said, and people should prepare themselves and their families the same way they would for an incoming storm.
The corps and Jindal have repeatedly said there’s no expectation of water overtopping the levees or breaking through. A breach in the levee is the worst-case scenario because overtopping could be addressed quickly, said Bryan Harmon, deputy director of Department of Public Works.
“A true failure would be the problem,” Harmon said.
The city-parish has met with industry, medical community, nursing homes, the school board and East Baton Rouge Parish Recreation and Park Commission about preparedness plans, he said.
“It’s not our intent to incite fear, but it’s important to be aware,” Harmon said.
A meeting for downtown property owners to discuss the rising Mississippi River has been called for 9:30 a.m. Thursday in the Governor Room of the Hilton Baton Rouge Capitol Center, 201 Lafayette St.
The Mayor’s Office of Homeland Security and Emergency Preparedness will host the meeting and downtown residents and business owners are encouraged to attend the informal meeting, which will include representatives from the Department of Public Works, said Davis Rhorer, executive director of the Downtown Development District.