The Corps’ Mississippi Valley New Orleans (MVN) did not open any bays on the Bonnet Carré Spillway (Mile 128.8 to 127.3 Above Head of Passes [AHP]) today (Thursday, June 6, 2019). The maximum flow above the Bonnet Carré today was 1.225 million cubic feet per second (cfs) based on the flow measured at Red River Landing (Mile 302.4 AHP), with the calculations and timing adjusted for the downriver flow at Bonnet Carré.
UPDATE: The operation of the Morganza Floodway (Spillway) at Mile 280 AHP has been postponed indefinitely:
“NEW ORLEANS – Based on the current forecast, the Corps will not operate the Morganza Floodway on June 9 and does not have an expected operating date. Future weather events could impact Mississippi River levels and the Corps will continue to monitor the forecast daily as conditions can change. Operation of the structure will be a consideration until the Mississippi River crests and begins to fall. The expected crest at Morganza is on or about June 15, but it will then remain high for two weeks or more. The Army Corps of Engineers only intends to operate the structure when needed as to not put additional water into the Atchafalaya Basin.”
The predicted crest above both Spillways is forecast to occur between June 16 to June 26 (2019).
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|
|5/18/19||16.80 feet||0||138||N/A||127,000 cfs|
|5/19/19||16.90 feet||10||148||N/A||142,000 cfs|
|5/20/19||16.80 feet||0||148||N/A||148,000 cfs|
|5/21/19||16.80 feet||20||168||N/A||161,000 cfs|
|5/22/19||16.80 feet||0||168||N/A||161,000 cfs|
|5/23/19||16.80 feet||0||168||N/A||158,000 cfs|
|5/24/19||16.70 feet||0||168||N/A||155,000 cfs|
|5/25/19||16.70 feet||0||168||N/A||155,000 cfs|
|5/26/19||16.60 feet||0||168||N/A||152,000 cfs|
|5/27/19||16.60 feet||0||168||N/A||157,000 cfs|
|5/28/19||16.60 feet||0||168||N/A||157,000 cfs|
|5/29/19||16.60 feet||0||168||N/A||149,000 cfs|
|5/30/19||16.60 feet||0||168||N/A||145,000 cfs|
|5/31/19||16.50 feet||0||168||N/A||140,000 cfs|
|6/1/19||16.50 feet||0||168||N/A||140,000 cfs|
|6/2/19||16.50 feet||0||168||N/A||140,000 cfs|
|6/3/19||16.50 feet||0||168||N/A||140,000 cfs|
|6/4/19||16.40 feet||0||168||N/A||138,000 cfs|
|6/5/19||16.40 feet||0||168||N/A||136,000 cfs|
|6/6/19||16.50 feet||0||168||N/A||142,000 cfs|
The stages below the Spillway(s) will be artificially controlled by the flow diverted from the Mississippi River through the open flood control structures.
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 cubic feet per second (cfs) in accordance with the approved Bonnet Carré Spillway Water Control Manual. The stages at the Carrollton Gauge are expected to remain steady cresting at approximately 16.7 feet based on the operation of the flood control structure(s).
The Morganza Floodway Structure is operated based on a trigger point flow of 1.5 million cubic feet per second at Red River Landing and under stage conditions designed to protect the flood control structures.
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.