S.C. Code § 49-19-2310
To maintain and preserve the ditches, drains, or other improvements made pursuant to this chapter and to repair and restore them when needed and for the purpose of defraying the current expenses of the district the board of supervisors may upon the completion of the improvements and on or before the first day of October in each year thereafter levy an assessment upon each tract or parcel of land within the district to be known as a "Maintenance Tax." The Maintenance Tax shall be apportioned upon the basis of the net assessments of benefits accruing for original construction, shall not exceed ten per cent thereof in any one year and shall be certified to the county treasurer of each county in which lands of the district are situate at the same time as the annual installment tax is certified but in a separate column under the heading Maintenance Tax. The county treasurer shall demand and collect the Maintenance Tax, make return thereof and receive the same compensation therefor and be liable for the same penalties for failure or neglect so to do as is provided for the annual installment tax.
S.C. Code § 49-19-2310