This update details the present status and efforts to recover and reopen the Mississippi River Ship Channel (MRSC) to limited or restricted vessel traffic. There are no dredges working, but the U.S. Army Corps of Engineers and the National Oceanic and Atmospheric Administration (NOAA) work to coordinate government survey equipment with contracted survey vessels to perform prioritized surveys across multiple channels impacted by Hurricane Ida. NOAA is also actively conducting overflights to collect aerial Emergency Response Imagery posted in Big Data files across a large portion of the area impacted by Hurricane Ida. Combined survey data will be utilized to make informed decisions when reopening the channel and deploying dredges and equipment. Ship traffic will be most likely limited to daylight transits only and the possibility remains that draft restrictions might also be required.
The efforts to recover the Ship Channel are focused upon channel surveys to ensure depth and identify possible obstructions including a number of barges and/or vessels that are reported either submersed or along the bank or river batture. The recovery efforts are also being impacted by the inability to move equipment, pilots, boat and dredge crews, and key maritime personnel to be able to transit downriver beyond the breech at Alliance (LA) that has cut off Highway 23 as the only the road to Venice.
The downed powerlines at Mile 107 Above Head of Passes, that cross the Ship Channel just above the Huey P. Long Bridge, have effectively split the Ship Channel into two halves. Vessels cannot transit through the area until the powerlines are removed. A MSIB was issued by the U.S. Coast Guard (USCG) that established a Temporary Safety Zone through this area.
TIMELINE:
Saturday, August 28, 2021 at 1400 hours:
The U.S. Coast Guard enacted Port Condition Zulu for all vessels from Mile 167.5 Above Head of Passes (AHP) to Mile 20 Below Head of Passes.
Saturday, August 28, 2021 at 2200 hours:
The U.S. Coast Guard enacted Port Condition Zulu for all vessels from Mile 303 AHP to Mile 20 BHP.
PORT CONDITION ZULU established full channel closures on the Ship Channel as detailed below, Port Condition Zulu is still in effect for vessels without an approved waiver from the USCG.
PORT RECONSTITUTION and INFORMATION REQUEST:
Monday August 30, 2021 at 1800 hours:
The U.S. Coast Guard issued a MSIB requesting input concerning priority vessel movement requests and updates from Regulated Waterfront Facilities in preparation of a conditional reopening of the Ship Channel.
TEMPORARY SAFETY ZONE:
Tuesday August 31, 2021 at 1330 hours:
The U.S. Coast Guard issued a MSIB to establish a temporary safety zone to prevent vessels from transiting in the reach of the Ship Channel near the downed power lines that cross the Ship Channel at approximately Mile 107 AHP. The following quote is reproduced is reproduced from the attachedMSIB:
“This safety zone will be implemented on the Lower Mississippi River between Mile Marker 105 (MM 105) and MM 108 AHP and is needed to protect persons and vessels from the safety hazards associated with the electrical transmission lines posing a threat of electrical transmission lines posing a threat of electrical shock present in the waterway.”
TIMELINE 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 storm surge from Hurricane Ida. The increase of 6.64 feet at the Carrollton Gauge in 24-hours shows the dramatic impact from Hurricane Ida with a water level spike of nearly 2.5 times the existing stage level in a one-day period.
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 storm surge and related precipitation receded, and stages returned to pre-Ida levels.
This morning (Wednesday, September 1, 2021) at 0800 hours the Carrollton Gauge reading was 4.89 feet with a
24-hour change of -0.53 feet.
COASTAL DATA INFORMATION PROGRAM:
The attached document details multiple sensors including the reading that wave buoys at the entrance of Southwest Pass peaked (CDIP 256) documented a maximum height (Hmax) of 47 feet and significant wave height of 26 feet (Hs) which is the average of the highest one-third of waves measured from trough to crest.
