S.C. Code Ann. § 59-71-340

The State Comptroller is directed in any year to levy and the State Treasurer is directed to collect in any school district which does not levy adequate millage for that year, to provide debt service to become due on bonds sold with the provision authorized by Section 1 of 1973 Act No. 378, an ad valorem tax on all taxable property in the school district without limit as to rate or amount sufficient to pay the principal of and interest on the bonds as they become due, including all bonds and coupons paid by him pursuant to Section 2 of 1973 Act No 378. A notice of such tax levy shall be provided to the district board by March first.