The Corps’ Mississippi Valley New Orleans (MVN) did not open or close any bays on the Bonnet Carré Spillway (Mile 128.8 to 127.3 Above Head of Passes [AHP]) today (Tuesday, July 9, 2019).  The maximum flow above the Bonnet CarréSpillway today was approximately 1.220 million cubic feet per second (cfs) based on the flow measured at Red River Landing (Mile 302.4 AHP), with thecalculations and timing adjusted for the downriver flow at Bonnet Carré.  The most recent crest (maximum flow) above the Bonnet Carré occurred between June 16 to June 17 (2019) with a maximum discharge through the Bonnet Carré Spillway of 161,000 cfs.

The MVN will begin closing bays when the tile gauge at the Spillway structure reaches 21.0 feet.  Based on present forecasts this could happen the third week of July (July 23, 2019).  The National Weather Service’s Extended Streamflow Prediction forecasts stage levels to remain steady for the next 10 days and to then begins a slow and steady fall, projecting a reading of 14.6 feet on August 6, 2019.

Precipitation associated with the Invest 92L/Storm 92 could alter current stage predictions, model storm tracks continue to converge on a southwestern/southcentral Louisiana landfall.  The Consecutive Days Above Flood Stage Table issued today by the National Weather Service is attached.

BONNET CARRÉ SPILLWAY SECOND OPERATION 2019

The MVN manages the opening and closing of bays on the Bonnet Carré Spillway as a flood control structure to ensure the maximum flow at New Orleans remains at/or below the trigger point flow of 1.25 million cfs in accordance with the approved Bonnet Carré  Spillway Water Control Manual.  The stages below the Spillway will be artificially controlled by the flow diverted from the Mississippi River via the flood control structure.

 The MVN operated the Bonnet Carré Spillway from February 27 to April 11, 2019, prior to 2019 the Spillway had never been operated in back-to-back years (2018 and 2019).  The required opening of the flood control structure twice in the same year represents another historic first and the Great Flood of 2019 continues to be record setting. 

Days Above Flood as of July 9 2019.pptx