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 (Thursday, July 11, 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 has no plans to open additional bays in response to the impact of Tropical Storm Barry.  Precipitation and potential storm surge associated with Tropical Storm Barry are expected to increase the river stages for a quick spike, but the stages are expected to return to their pre-storm level promptly (approximately 16 feet).  The current estimates indicate this rise will start late tomorrow afternoon (Friday, July 12, 2019) increasing from near 16 feet to 19 feet by the afternoon of Saturday, July 13, 2019 and then beginning to return to near present levels.  Tropical Storm Barry’s track and intensity will determine exactly how high this spike is, yesterday’s forecast indicated this spike would reach 20 feet.   

The MVN intends to begin closing bays when the tile gauge at the Spillway structure reaches 21.0 feet, present forecasts predict this to occur by the end of next week.

 

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 79,000 cfs
5/11/19 16.80 feet 10 70 N/A 83,000 cfs
5/12/19 16.80 feet 0 70 N/A 86,000 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 122,000 cfs
5/16/19 16.60 feet 0 138 N/A 124,000 cfs
5/17/19 16.60 feet 0 138 N/A 127,000 cfs
5/18/19 16.80 feet 0 138 N/A 142,000 cfs
5/19/19 16.90 feet 10 148 N/A 148,000 cfs
5/20/19 16.80 feet 0 148 N/A 161,000 cfs
5/21/19 16.80 feet 20 168 N/A 161,000 cfs
5/22/19 16.80 feet 0 168 N/A 158,000 cfs
5/23/19 16.80 feet 0 168 N/A 155,000 cfs
5/24/19 16.70 feet 0 168 N/A 158,000 cfs
5/25/19 16.70 feet 0 168 N/A 158,000 cfs
5/26/19 16.60 feet 0 168 N/A 159,000 cfs
5/27/19 16.60 feet 0 168 N/A 158,000 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 141,000 cfs
6/1/19 16.50 feet 0 168 N/A 143,000 cfs
6/2/19 16.50 feet 0 168 N/A 135,000 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 138,000 cfs
6/7/19 16.60 feet 0 168 N/A 138,000 cfs
6/8/19 16.60 feet 0 168 N/A 144,000 cfs
6/9/19 16.50 feet 0 168 N/A 146,000 cfs
6/10/19 16.60 feet 0 168 N/A 146,000 cfs
6/11/19 16.60 feet 0 168 N/A 147,000 cfs
6/12/19 16.60 feet 0 168 N/A 147,000 cfs
6/13/19 16.60 feet 0 168 N/A 144,000 cfs
6/14/19 16.60 feet 0 168 N/A 147,000 cfs
6/15/19 16.60 feet 0 168 N/A 150,000 cfs
6/16/19 16.50 feet 0 168 N/A 146,000 cfs
6/17/19 16.70 feet 0 168 N/A 147,000 cfs
6/18/19 16.60 feet 0 168 N/A 142,000 cfs
6/19/19 16.50 feet 0 168 N/A 137,000 cfs
6/20/19 16.40 feet 0 168 N/A 131,000 cfs
6/21/19 16.40 feet 0 168 N/A 130,000 cfs
6/22/19 16.35 feet 0 168 N/A 124,000 cfs
6/23/19 16.20 feet 0 168 N/A 115,000 cfs
6/24/19 16.10 feet 0 168 N/A 116,000 cfs
6/25/19 16.10 feet 0 168 N/A 110,000 cfs
6/26/19 16.10 feet 0 168 N/A 108,000 cfs
6/27/19 16.00 feet 0 168 N/A 108,000 cfs
6/28/19 15.95 feet 0 168 N/A 106,000 cfs
6/29/19 15.95 feet 0 168 N/A 106,000 cfs
6/30/19 15.95 feet 0 168 N/A 106,000 cfs
7/1/19 15.95 feet 0 168 N/A 110,000 cfs
7/2/19 15.95 feet 0 168 N/A 108,000 cfs
7/3/19 15.95 feet 0 168 N/A 104,000 cfs
7/4/19 15.95 feet 0 168 N/A 103,000 cfs
7/5/19 15.95 feet 0 168 N/A 102,000 cfs
7/6/19 15.95 feet 0 168 N/A 106,000 cfs
7/7/19 15.95 feet 0 168 N/A 109,000 cfs
7/8/19 15.95 feet 0 168 N/A 112,000 cfs
7/9/19 15.95 feet 0 168 N/A 112,000 cfs
7/10/19 15.95 feet 0 168 N/A 112,000 cfs
7/11/19 16.10 feet 0 168 N/A 115,000 cfs

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.