Science Cafe: Five Feet High and Rising - Historical and Ecological Perspectives on the Bonnet Carre Spillway

On May 31, 2019, Governor Phil Bryant issued a disaster declaration for the State of Mississippi in response to adverse ecoogical impacts resulting from the opening of the Bonnet Carre spillway (BCS). Operated by the United States Army Corps of Engineers (USACE) to protect New Orleans from potential flooding, the BCS diverts Mississippi River flood waters into Lake Pontchartrain, which ultimately flow into the Mississippi Sound. These periodic openings of the BCS introduce significant amounts of freshwater, inorganic nutrients, and organic matter that immediately alter the physical, biological, and chemical properties within Lake Pontchartrain and local coastal waters. Since it was built in 1931, the BCS has been opened 14 times, with openings lasting between 13 and 75 days. Though it has been opened on average every seven years, the BCS has opened four times since 2016, and twice in 2019, which is unprecedented in its 88-year history. This talk will focus on the history of the spillway and will highlight some of the ecological impacts on our coastal and marine resources due to Mississippi River-borne flood waters.