S.C. Code Ann. § 3-5-80

For the purpose of determining the lands, easements and property necessary for the uses herein set out, the South Carolina Department of Health and Environmental Control or the United States Government, or the agents of either, may enter upon any lands along the general line of the rights of way for the purposes of locating definitely the specific lines of such rights of way and the land required for such purposes and there shall be no claim against the State or the United States for such acts as may be done in making such surveys.