Rising water in the Mississippi River has state and federal agencies on alert as flooding is expected to get close to what south Louisiana saw in 2011, when both the Bonnet Carré and Morganza spillways were opened.
Long-range river forecasts call for the river to rise to 44 feet in Baton Rouge by Jan. 19 and to 17 feet in New Orleans by Jan. 9. The level in New Orleans will be kept to no higher than 17 feet by the opening of various spillways.
It’s unclear if either the Morganza or Bonnet Carré spillways will be opened this year, but a decision will be made about the Bonnet Carré by Jan. 9, said Mike Stack, chief of emergency management at the U.S. Army Corps of Engineers’ New Orleans district.
The trigger to open the spillway is hit when the river is flowing at 1.25 million cubic feet per second and is expected to rise, he said. Currently, the district is evaluating the forecasts and doing other preparation work to make that decision, he said.
“Right now, we see it’s certainly possible it will hit the Bonnet Carré trigger as soon as the 9th,” he said. “This river is rising very fast.”
The last time the spillway was opened in January was back in 1937, its first year of operation.
The Morganza Spillway into the Atchafalaya River Basin is always the second consideration and is opened when river levels reach 57 feet at the structure north of Baton Rouge and when there is a 10-day forecast of river water flowing at 1.5 million cfs, Stack said. Although the current forecast shows it’s likely the levels will reach 57 feet, forecasts so far aren’t showing the 1.5 million cfs flow will occur, although that can change.
“That one (decision) is further out, so it’s more uncertain,” Stack said.
In 2011, the river stage at Baton Rouge was expected to hit 47.5 feet but was kept at just 44.8 feet after the Corps opened a number of flood control structures.
Rising river levels have levee districts and the Corps conducting twice-a-week inspections, but it’s expected those will increase to daily inspections on the Mississippi River and Atchafalaya River levees next week.
In Baton Rouge, the city-parish Department of Public Works conducts the inspections along a 1.5-mile stretch of levee downtown, while the Pontchartrain Levee District picks up the levee inspections on the east bank just north of LSU.
Monica Salins, executive director of the Pontchartrain Levee District, said the district is preparing for this early high water, a situation not usually seen until the spring.
Some of those preparations include the twice-weekly inspections for any potential avenues for water to seep through levees, such as animal burrows.
“So far, so good,” she said.
In addition, crews are speeding the cleanup from last week’s Christmas Eve bonfires on the levee to have everything done by the time higher water levels require the expected daily inspections next week.
“It’s just going to be a monitoring game now, like in 2011,” Salins said.
To help maintain the strength of the levees, a number of restrictions are in place, including no construction within 1,500 feet of the levee and no vehicle access; they were widely followed during the bonfire preparations, she said.
“The residents understand and appreciate what that levee holds back,” Salins said.
One area that created more worry during the 2011 flood was at Duncan Point near Farr Park in Baton Rouge, where water seeping under the levee created sand boils and some soggy ground, and filled ditches in nearby neighborhoods. The area has been a potential worry point for years.
After the 2011 floods, an $8 million project increased the size and weight of the landward side of the levee to help push back against the pressure caused during high water.
“This will be a test of that construction,” Salins said.
In addition to human safety, state agencies are urging caution for animal safety as well, with some new warnings and restrictions.
The state Department of Agriculture and Forestry is urging livestock owners to monitor river levels and, if evacuations are recommended, to leave as early as possible to avoid road closures.
The high water is also prompting the state Department of Wildlife and Fisheries to close deer hunting season in parts of northeast and central Louisiana because of potential flooding. Starting at sunset Jan. 3, the season will close from east of U.S. 65 from the Arkansas state line to north of Vidalia and west of the Louisiana-Mississippi border. The season will be back on once floodwaters recede.
Unlike 2011, this river flood event is the result of heavy rainfall in the Arkansas, Mississippi and Ohio river valleys instead of snow melt, said Jeff Graschel, a service coordination hydrologist with the National Weather Service Lower Mississippi River Forecast Center.
Those areas have seen 5 to 10 inches more rain than normal in the past few weeks, and that water is making its way down the river systems and into the Mississippi River.
That additional water also will affect water levels in the Atchafalaya River, bringing flood situations that will look similar to the 2011 floods in the upper parts of the system but will not be as severe for areas such as Morgan City, Graschel said.
A number of parishes already have issued declarations of emergency in preparation for any assistance they might require, said Mike Steele, a Governor’s Office of Homeland Security and Emergency Preparedness spokesman. Some of the early declarations came from Concordia, East Carroll, Madison and West Feliciana parishes, but more are likely to follow, he said.
Steele said the office is working with both the incoming and outgoing governors’ staffs because some actions likely will bridge the two administrations.
Follow Amy Wold on Twitter, @awold10 .