The U.S. Army Corps of Engineers (USACE) continues working to restore authorized channel dimensions along the Mississippi River Ship Channel (MRSC). The USACE is working with the owners of the previously identified obstructions in the Venice Corridor to document accurate depths over the pipelines and utility cable. The concern regarding these obstructions will continue to delay the mechanically deepened channel being opened up to deeper vessel traffic until accurate depth of cover surveys provide integrity to the decision-making process. The dustpan dredges are currently working to maintain federally authorized channel dimensions on the Crossings, which remain 45 feet deep by 500 feet wide. The USACE expects to commence Phase 2 of the MRSC deepening to 50 feet at Fairview Crossing (Mile 115 Above Head of Passes [AHP]) in October (2021).
DUSTPAN DREDGES WORKING ON THE CROSSINGS ABOVE NEW ORLEANS:
WALLACE McGEORGE: The industry dustpan dredge WALLACE McGEORGE continues dredging full channel dimensions (500 feet) at Red Eye Crossing (Mile 224 AHP). The dustpan began dredging on the Crossings on May 20, 2021, then sought safe harbor from Hurricane Ida on August 28 and returned to work at Red Eye Crossing on September 2, 2021.
JADWIN: The government dustpan dredge JADWIN continues dredging full channel dimensions (500 feet) at Belmont Crossing (Mile 154 AHP). The JADWIN began work on the Crossings on June 24 and sought safe harbor from Hurricane Ida on August 28 and returned to work at Belmont Crossing on September 2, 2021.
CUTTERHEAD DREDGE(S) IN THE HOPPER DREDGE DISPOSAL AREA (HDDA):
ILLINOIS: The cutterhead dredge ILLINOIS (Great Lakes Dredge and Dock) completed work under Hopper Dredge Disposal Area Cutterhead Rental Contract #1-2019 at 2146 hours last night. The dredging operations removed and beneficially utilized approximately 12.0 million cubic yards (mcy) of material from the HDDA. The Coalition estimates the 12 mcy would restore approximately 1,000 acres of new land in the environmentally sensitive birds-foot delta within the West Bay Receiving Area (Below Venice, LA).
The two 12-hour closures needed to remove the submerged dredge pipeline have been rescheduled to the following dates: September 14; September 19 and (possibly) September 21 (2021). GLDD confirmed being ready for the first closure on September 14, 2021.The Ship Channel will be closed to all vessels from Mile 2.0 Above Head of Passes (AHP) to Mile 0 (Head of Passes) during the two scheduled 12-hour closures (0600 hours to 1800 hours).The third closure is scheduled only as a back-up date and should not be needed.
CUTTERHEAD DREDGE(S) IN THE HOPPER DREDGE DISPOSAL AREA (HDDA):
On days of closures: all vessels will be restricted from transiting between Mile 2.0 AHP and Mile 0 (Head of Passes) from 0600 to 1800 hours. Vessels intending to arrive or depart the Mississippi River on the day of a closure must arrive at Pilottown (outbound) no later than 0400 hours or arrive Southwest Pass Entrance Light (inbound) no later than 0330 hours.
The U.S. Coast Guard’s updated Marine Safety Information Bulletin (MSIB) on the pipeline removal operations with scheduled closure dates and details is attached.
MISSISSIPPI RIVER STAGE UPDATES:
The Carrollton Gauge (New Orleans) reading at 0700 hours today was 4.24 feet with a 24-hour change of + 0.25 feet. The National Oceanic and Atmospheric Administration’s (NOAA) National Weather Service Extended Streamflow Prediction (28-Day) for the Carrollton Gauge issued today forecasts stages will slowly rise to 5.4 feet by September 15 and then begin a slow fall to 2.4 feet on October 9 (2021). The highest crest recorded on the Carrollton Gauge in 2021 to date is 15.44 feet at 1700 hours on April 16, 2021.
The Carrollton Gauge crest attributed to the precipitation and coastal storm surge from Hurricane Ida was recorded at 1400 hours on Sunday, August 29, 2021 with a reading of 11.36 feet.
The Baton Rouge Gauge reading at 0800 hours was 12.91 feet with a 24-hour change of + 0.93 feet. The coastal surge crest recorded at Baton Rouge driven by Hurricane Ida was 17.35 feet at 0200 hours on August 30, 2021. The National Oceanic and Atmospheric Administration’s (NOAA) National Weather Service Extended Streamflow Prediction (28-Day) for the Baton Rouge Gauge issued today forecasts stages will slowly rise to 15.7 feet on September 15 and then begin a slow fall down to 4.1 feet on October 9 (2021). A reading of 4.1 feet on the Baton Rouge gauge would present some low water advisories and restrictions – of course all stage forecasts are actively updated daily and precipitation can greatly change these predications.
MISSISSIPPI RIVER STAGES DRIVEN BY HURRICANE IDA:
Saturday August 28, 2021 at 1400 hours the Carrollton Gauge (New Orleans) reading was 4.72 feet (pre-Hurricane Ida storm surge).
Sunday August 29, 2021 at 1400 hours the Carrollton Gauge crested at 11.36 feet, driven by precipitation and coastal surge from Hurricane Ida.
Monday, August 30, 2021 at 1400 hours the Carrollton Gauge reading was 6.23 feet as the storm surge began to recede.
Tuesday, August 31, 2021 at 1400 hours the Carrollton Gauge reading was 4.93 feet as the coastal surge and related precipitation receded and stages returned to pre-Ida levels.
