Upon the conveyance to the United States, free of cost, title to the land occupied by what is known as the "Kyle and Young Canal" and the "Morrison Landing extension" of the same, on the Oklawaha River, in the State of Florida, together with title to a strip of land on the east side of said canal of such width as in the judgment of the Secretary of the Army may be required for the future widening of said canal and extension by the United States, the said canal and extension shall become a free public waterway of the United States in place of the natural bed of the river.