S.C. Code Ann. § 6-21-150

In the event of the acquisition by purchase or condemnation of any works already constructed the governing body, at or before the time of the adoption of the ordinance or resolution described in SECTION 6-21-160, shall cause to be determined what repairs, replacements, additions and betterments will be necessary in order that such works may be effective for their purpose, and an estimate of the cost of such improvements shall be included in the estimate of the cost required by SECTION 6-21-140 and such improvements shall be made upon the acquisition of the works and as a part of the cost thereof.