Bayou St. John
Sector Gate

The water flow from Lake Pontchartrain into Bayou St. John is critical to the health of many species that call it home

At Lake Pontchartrain

The Bayou St. John Flood Control Structure is located at the mouth of the bayou and Lake Pontchartrain. The purpose of the structure is to prevent storm surge from Lake Pontchartrain from entering the bayou which could lead to flooding in the surrounding neighborhoods.

The structure’s components include one sector gate and three sluice gates that allow tidal exchange between the lake and the bayou. Given that Bayou St. John is designated as an Historic and Scenic Waterway, the Flood Protection Authority worked with the U.S Army Corps of Engineers and the Louisiana Department of Wildlife and Fisheries to design and construct the structure so as not to impact the ecological health of the bayou.

Operation & Maintenance


The Flood Protection Authority is responsible for the structure’s operation and maintenance. Flood Authority crews perform maintenance once per week and monitor the water level in the bayou. Water levels determine when the structure can be opened and closed. The Flood Authority works in cooperation with the New Orleans Sewerage and Water Board to allow for storm water drainage when necessary. The health of the lagoons in New Orleans City Park rely on the bayou’s waterflow, therefore, the Flood Authority communicates with Park staff regarding opening and closing the structure. The Louisiana Department of Wildlife and Fisheries and the Pontchartrain Conservancy provide the Flood Authority with information about the bayou’s water quality and invasive species which can be harmful to the bayou’s ecology. These data are used to aid decision making about opening and closing the structure.