Lower Mississippi River (LMR) Dredging Update 123015

Members,

The National Weather Service’s (NWS) Extended Streamflow Prediction (28-Day Mississippi River Forecast) released this afternoon (Wednesday, December 30, 2015) projects a crest of 17 feet on the Carrollton Gauge on January 9, 2016.  The 28-Day Forecast shows 17 feet on the Carrollton Gauge from January 9 to January 27, 2016.  The NWS’s predictions are based on the anticipated opening of the Bonnet Carre Spillway (presumably on January 9, 2016). 

However, the Corps’ Operation Manual for opening the Bonnet Carre Spillway is based on a flow of 1.25 million cubic feet per second (cfs) passing New Orleans.  Historically, this trigger point is reached when the Carrollton Gauge reads approximately 17 feet.  Although, the Corps is not ready to announce the opening of the Bonnet Carre Spillway the flow passing New Orleans yesterday (Tuesday, December 29, 2015) was recorded at approximately 820,000 cfs with a corresponding stage level of about 12.25 feet on the Carrollton Gauge.

The NWS predicts that the stage level at Donaldsonville will crest on January 20, 2016 at 32 feet and then begin to slowly fall, the gauge at Donaldsonville is  at Mile 137.6 AHP and the Bonnet Carre Spillway extends from Mile 128.8 to Mile 127.3 AHP.

Best Regards,

Sean