Mississippi River flood fight operations update

Published March 5, 2018

Mississippi River flood fight operations update

NEW ORLEANS – The U.S. Army Corps of Engineers, New Orleans District has activated Phase II flood fight procedures today to monitor levees along the Mississippi River.

Closely coordinating efforts with the local levee authorities, the New Orleans District will begin daily patrolling of levees along the Mississippi River from Baton Rouge to Venice. Increased patrols help ensure our ability to respond quickly to any problem areas that may develop along the levee system because of the elevated water levels.  

In Phase II, construction projects within 1500 feet of the levee system that were previously permitted must be shut down.                   

Additionally, the Army Corps initiated phase I flood fight operations on the Lower Atchafalaya Friday, March 2, and on the Upper Atchafalaya today with levee inspections being conducted once a week.

Bonnet Carre’ Spillway
The Mississippi River and Tributaries project is designed to pass a flow of 1.25 million cubic feet per second downriver from the Bonnet Carre` Spillway. On March 8 the river is projected to reach that flow rate and it is the recommendation of the New Orleans District to operate the Bonnet Carre` Spillway.

Crews will be at the spillway this week to prepare for the operation of the structure. Site preparation includes crew readiness training, and maintenance and testing of mechanical features. St. Charles Parish closed Bonnet Carre` Spillway road Saturday and the ATV trails in the spillway were closed Friday afternoon.

Overbank Structure at the Old River Control Complex
The Army Corps opened six bays of the Old River Overbank Structure Feb. 28 when the Mississippi River was projected to reach the trigger of 52 feet at the Knox Landing gage.

The Overbank Structure, only operated during high water events, increases the Corps’ ability to relieve pressure from the Auxiliary and Low-Sill structures, helping to reduce the potential for structural damages as a result of diverting large river flows.

This opening is the 16th time the structure has been operated and only the fourth time since 1990. The Overbank Structure is one of three Old River Control Complex structures designed to implement the 70/30 distribution rate between the Mississippi and Atchafalaya rivers.

Morganza Floodway
Based on current Mississippi River forecasts and hydraulic modeling, the Army Corps does not anticipate operating the Morganza Control Structure during this high water event.

The operational trigger for the Morganza Control Structure is when river levels reach 57 feet at the structure with a forecast flow of 1.5 million cubic feet per second. The current forecasts show the river height reach 60 feet at the structure March 20 but the projected peak flow rate will be 1.4 million cfs. This rate of flow is within the design capacity for the Mississippi River levees between the Morganza Floodway and the Bonnet Carre’ Spillway. 

The safety of the public is the Army Corps of Engineers top priority. The Mississippi River and Tributaries System is designed to pass ‎high water events like we are currently experiencing. The Army Corps of Engineers will leverage all of its resources and work with our partners at the state, local and federal level to ensure this system performs as designed and safely passes the high water through the Mississippi Valley.




Matt Roe

Release no. 18-007