33 U.S. Code § -
(a) Definition of Great Lake
In this section, the term “Great Lake” means Lake Superior, Lake Michigan, Lake Huron (including Lake St. Clair), Lake Erie, and Lake Ontario (including the St. Lawrence River to the 45th parallel of latitude).
(b) Dredging levels
In operating and maintaining Federal channels and harbors of, and the connecting channels between, the Great Lakes, the Secretary shall conduct such dredging as is necessary to ensure minimal operation depths consistent with the original authorized depths of the channels and harbors when water levels in the Great Lakes are, or are forecast to be, below the International Great Lakes Datum of 1985.