Introduction

The Bonnet Carre' Spillway is a vital element of the comprehensive plan for flood control in the Lower Mississippi Valley. This multi-state plan, called the Mississippi River and Tributaries Project (MR&T;), provides flood protection for the alluvial valley between Cape Girardeau, Missouri, and the mouth of the river. Due to the wide expanse of the project and the complex problems involved, the plan contains an array of features. The MR&T; Project provides for levees to contain flood flows, floodways such as the Bonnet Carre' to redirect excess flows away from the Mississippi River, plus features such as channel improvement and river bank stabilization for efficient navigation and protection of the levee system. It also involves reservoirs and pumping plants for flood control drainage.

Floodways and flow distribution during major floods in the Lower Mississippi River Valley

The Bonnet Carre' Spillway is the southernmost floodway in the MR&T; system. Located in St. Charles Parish, Louisiana, the spillway protects New Orleans and other downstream communities during major floods on the Mississippi River. This protection is accomplished by diverting a portion of the flood waters into Lake Pontchartrain and thence into the Gulf of Mexico, bypassing New Orleans. This spillway was first opened during the flood of 1937, and seven times thereafter through 1997 to lower river stages at New Orleans.

The spillway is part of the Mississippi River Levee System. The spillway extends northward to Lake Ponchartrain.

The Bonnet Carre Spillway consists of two basic components: a control structure along the east bank of the Mississippi River and a floodway that conveys the diverted flood waters to the lake. The control structure is a mechanically controlled concrete weir which extends for over a mile and a half parallel to the river. Confined by guide levees, the floodway stretches nearly six miles to Lake Pontchartrain.

The spillway (highlighted in green) stretches from the Mississippi River, ,at right, northward to Lake Ponchartrain, on the left of the photo.

In addition to its flood control function, the project's nearly 8,000-acre floodway is the site of diverse and extensive recreational activities. Also of importance are the fish and wildlife benefits derived from the floodway's varied habitats and the introduction of fresh water and nutrients into the Lake Pontchartrain estuary.

The POC for this page:
Jim Addison, CEMVN-PA
Chief, Public Affairs Office
New Orleans, LA
504-862-2201
James.D.Addison@MVN02.usace.army.mil

Page last updated: 6 May 1999