S.C. Code Ann. § 5-3-155: Rules for annexation of certain properties by municipalities.

An area in this State located more than twelve miles from the Atlantic Ocean, which is a peninsula being predominately industrial in character, separating a freshwater reservoir from a body of brackish water subject to tidal influences, and created by the construction of a manmade canal and manmade dam, may be annexed by a municipality only under the provisions of Section 5-3-150.