The Corps’ Mississippi Valley New Orleans (MVN) did not open any additional bays on the Bonnet Carré Spillway yesterday (Thursday, May 16, 2019) and has no plans to open any today (Friday, May 17, 2019).
The MVN manages the opening and closing of bays to ensure the maximum flow at New Orleans remains at/or below the trigger point flow of 1.25 million cubic feet per second (cfs). The MVN will continue to oversee the operation of the Spillway as a flood control structure in accordance with the approved Bonnet Carré Spillway Water Control Manual.
The maximum flow above the Spillway today was 1.30 million cfs based on the flow measured at Red River Landing, with calculations and timing adjusted for downriver at Bonnet Carré. The MVN indicated that the operation of the Spillway is expected to continue “well into June.”
BONNET CARRÉ SPILLWAY SECOND OPERATION 2019
|DATE||CARROLTON GAUGE (NEW ORLEANS)||BAYS OPENED TODAY||TOTAL NUMBER OF BAYS OPEN||TOTAL NUMBER OF BAYS CLOSED||SPILLWAY DISCHARGE CUBIC FEET PER SECOND (cfs)|
|5/10/19||17.25 feet||60||60||N/A||78,000 cfs|
|5/11/19||16.80 feet||10||70||N/A||82,000 cfs|
|5/12/19||16.80 feet||0||70||N/A||79,000 cfs|
|5/13/19||17.00 feet||58||128||N/A||116,000 cfs|
|5/14/19||16.75 feet||10||138||N/A||127,000 cfs|
|5/15/19||16.70 feet||0||138||N/A||127,000 cfs|
|5/16/19||16.60 feet||0||138||N/A||122,000 cfs|
|5/17/19||16.60 feet||0||138||N/A||122,000 cfs|
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.
The MVN advised that the flow conditions have stabilized and that additional bays will most likely not be opened until Sunday or Monday (May 19th or 20th). Present conditions and updated forecasts for the Carrolton Gauge indicate the stage will remain at approximately 16.6 feet until May 24, 2019 before beginning a slow fall. The stages below the Spillway will be artificially controlled by the flow diverted form the Mississippi River through the open flood control structure and into Lake Pontchartrain.
The MVN predicts the crest above the Spillway will occur between May 21 and May 27 (2019).