S.C. Code Ann. § 57-17-20

The governing body of any county may also open new public roads and widen or change the location of old public roads when, in its judgment, such change would be for the material interest of the traveling public. It may obtain the right of way for public roads or the drainage of public roads by gift or purchase or it may condemn the lands therefor and assess the compensation and damages therefor as is herein provided. It may call to its assistance a surveyor who shall survey and lay off such roads, under its direction, so that the grade shall not exceed seven and a half inches to the crown.