S.C. Code § 5-21-20
Nothing in Section 5-21-10 contained shall apply to any debt contracted or to any note, bond, draft or obligation executed, indorsed or guaranteed by the city council of such city and approved and confirmed by a two-thirds vote of the whole of such city council, at a regular meeting thereof, for the purpose of (a) the establishment of a sewage system, (b) securing a supply of water or light for its public use, by contract or (c) the lease, purchase, construction or operation by the city council of any plant for waterworks or lighting purposes, one or both. For any of such purposes the city council may create debts and incur liabilities beyond the municipal income of the current year, upon the same being approved and confirmed by a two-thirds vote of the whole of the city council at a regular meeting thereof. But no purchase or construction of any such plant for waterworks or lighting purposes shall be made by the city council except upon a majority vote of the electors in such city who are qualified to vote on the bonded indebtedness of the city.
S.C. Code § 5-21-20