Although early in the flood season, the Mississippi River is rising and has already overtaken Spillway Road in Norco.
Fast rising waters swollen by December’s heavy rain from north of the Mississippi River Valley are pouring into the spillway, said U.S. Army Corps of Engineers spokesman Matt Roe. The road was closed Jan. 4.
The river reaching 15 feet at the Carrollton Gauge prompted the Corps in New Orleans to step up to daily inspections of the river levees.
Roe said the National Weather Service forecast the river remaining above 15 feet through Jan. 25, and expected to crest at 15.5 feet on Jan. 21. The level has to reach 17 feet high to trigger opening the Bonnet Carre’ Spillway.
“However, river conditions are changing daily and may result in extending the flood fight inspections,” Roe said.
Increased patrols help ensure the Corps and levee districts’ ability to respond quickly to any areas of concern that may develop along the levee system because of the elevated water levels, he said.
Roe also emphasized when the river is above 11 feet at the Carrollton Gauge all work within 1,500 feet of the levee must be suspended unless a waiver is granted by the Corps of Engineers and levee district. However, when the river is above 15 feet, all work is suspended.
The Phase II activation applies to the levees along the river from Baton Rouge to Venice.
“We’re always prepared, but right now, there’s no indication we’ll need to open up anything” – Chris Brantley
On Thursday at 9:30 a.m., the Corps will practice removing and replacing up to 20 needles on the weir as a practice exercise.
Rising waters from rain and melted snow typically comes in March to early June, he said. But the Corps is keeping an eye on weather conditions.
Though the recent flooding locally as result of heavy rain has led some to speculate the Bonnet Carre Spillway could be opened for the second consecutive year, there are no plans to do so at this time.
Chris Brantley, the spillway’s project manager for the U.S. Army Corps of Engineers, said the decision to open comes when the river is flowing past the spillway toward New Orleans at a rate of 1.25 million cubic feet per second. Brantley said the current rate stands at 1.1 million.
“We’re always prepared, but right now, there’s no indication we’ll need to open up anything,” Brantley said. “There’s a little more capacity right now. Now if it fills to capacity and there’s the potential for more water to come, that’s what they’ll look at and then you’ll have the potential to open it. But we’re not sure right now that we’ll have a lot more water coming.
“The river is high, a high discharge, but that may not necessitate it being opened.”
The spillway has been in existence for 91 years but has only opened 12 times in that time. It has been opened two times in the past three years and four times total since 2008. The most recent occasion came on March 8 of last year, and prior to that openings in 2016, 2011 and 2008. Last year’s opening saw roughly half of the spillway’s 350 bays opened. The last time all bays were opened came in 1983.
Bonnet Carre Spillway
- The spillway was built in 1931. Congress authorized construction of the structure after the historic 1927 Mississippi River flood to divert flooding from populated areas like New Orleans.
- The spillway consists of two basic components: a control structure along the east bank of the Mississippi River and a spillway that conveys the diverted floodwaters to Lake Ponchartrain.
- The spillway is nearly 8,000 acres.