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 (Tuesday, June 18, 2019).  The maximum flow above the Bonnet Carré Spillway today was 1.25 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.  The immediate crest (maximum flow) above the Bonnet Carré has apparently passed, the records now show it occurred from June 16 to June 17 (2019).

The MVN reports that the Midwest and central U.S. rain forecasts have begun to influence stage predictions, indicating a moderate reduction in flow through June 29th, and then a flat prediction through the end of the forecast on July 9th.

The operation of the Morganza Floodway (Spillway) at Mile 280 AHP has been postponed indefinitely:

“The opening of the Morganza Floodway has been postponed indefinitely.  Operation of the structure does not appear necessary, as long as the current forecast holds.  The crest at Morganza is was June 15th-16th.”  

                                                                              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

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 management 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.