S.C. Code § 3-5-30
The Governor and Secretary of State may issue to the United States of America a grant or grants within such limits as above specified of a perpetual right and easement to enter upon, excavate, cut away and remove any and all of the land raised above water as mentioned in Section 3-5-20, including submerged land, composing a part of the prism required for the channels, anchorage areas and turning basin, their slopes and berms, as may be required at any time for the construction and maintenance of said intracoastal waterway from Winyah Bay, South Carolina, to the State boundary line in the Savannah River and any changes, modifications or extensions thereto and any tributaries thereof and for the Ashley River and Shipyard River projects and to maintain the portions so excavated and the channels, anchorage areas and turning basin thereby created as a part of the navigable waters of the United States and a further perpetual right and easement to enter upon, occupy and use any portion of such land, including submerged land, composing a part of the spoil disposal areas not so cut away and converted into public navigable waters, as aforesaid, for the deposit of dredged material and for such other purposes as may be needful in the construction, maintenance and improvement of such intracoastal waterway and any changes, modifications or extensions thereto and any tributaries thereof and the Ashley River and Shipyard River projects, the grant or grants to issue upon a certificate furnished to the Governor by some authorized official of the United States as provided in Section 3-5-10.
S.C. Code § 3-5-30