For the purpose of aiding in the construction and maintenance by the United States of the projects approved by Congress by the River and Harbor Act approved August 26, 1937 for the construction of the intracoastal waterway from the Cape Fear River, North Carolina, to the Savannah River, Georgia (Rivers and Harbors Committee Document No. 6, 75th Congress, first session), of the Ashley River, South Carolina, project (House Document No. 449, 74th Congress, second session) and of the Shipyard River, South Carolina, project (Rivers and Harbors Committee Document No. 38, 75th Congress, first session) and any changes, modifications or extensions thereto and any tributaries thereof, the Governor and the Secretary of State may issue to the United States of America a grant or grants of a perpetual right and easement to enter upon, excavate, cut away and remove any and all of the land, including submerged lands, composing a part of the prism required for the channels, anchorage areas and turning basin, and their slopes and berms, as may be required at any time for 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 said 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 the land, including submerged land, composing a part of the spoil disposal area 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 said intracoastal waterway and any changes, modifications or extensions thereto and any tributaries thereof and of the Ashley River and Shipyard River projects, in so far as such lands, including submerged lands, are subject to grant by the State, such grant to issue upon a certificate showing the location and description of such rights of way and spoil disposal areas furnished to the Governor by the Secretary of the Army, any authorized officer of the Corps of Engineers of the United States Army or any other authorized official exercising control over the construction or maintenance of such projects.