USCG: Extreme Low Water Advisory for Sector Upper Mississippi River

Marine Safety Information Bulletin #11-22

The Captain of the Port Upper Mississippi River has issued a Safety Advisory for all waters of the Upper Mississippi River (UMR) from Mile Marker (MM) 185.4 TO MM 109.9 as a result of extreme low water conditions. This safety advisory is needed to protect vessels and mariners from hazards associated with low water, including possible shoaling and decreased channel widths. This safety advisory is effective immediately with the following provisions as listed in the Waterways Action Plan (WAP) Upper Mississippi River Annex

During periods of low water as listed in the low water watch phase of the WAP (0’ to -2’) it is advised to take the following
precautions:

• Advise deep draft vessels to depart any areas of low water with a reminder to transit at a slow speed near fleeting areas to
  minimize impact.
• Place heavy barges in the middle of a tow and be aware of shifting channels.

During periods of low water as listed in the low water action phase of the WAP (-2’ to -3.25’) it is advised to take the following
precautions:

• Be aware of shifting channels, emergency dredging may be required at some locations.
• Consider restrictions on single skin barge movement.
• Recommend all vessels reduce draft to 9 feet or less.

During periods of extreme low water as listed in the WAP (-3.25’ and below) it is advised to take the following precautions:

• Be prepared for severe restriction of navigation if conditions warrant.
• Fleeting may continue if conditions warrant.

Proactive risk mitigation strategies should be utilized to safely navigate in low water conditions. Operators should closely monitor river gauge readings while transiting pools and river systems. Owners, operators and port captains preparing barges must be mindful of the drafts, particularly anticipated under keel clearance, to ensure a safe transit.

To receive the latest information, monitor marine VHF channels 14 and 16, the Upper Mississippi River Port Directory at https://homeport.uscg.mil/port-directory/upper-mississippi-river-(st-louis). Hazardous conditions and marine casualty notifications should be made to the Western Rivers Command Center at (314) 269-2332 or (314) 269-2463 – these numbers are continuously
monitored.

//signed//

R. G. CHERKAUER
Lieutenant Commander, U. S. Coast Guard
Chief, Waterways Management Division