SDCL § 9-43-78: Calculation of special assessments--Property outside municipal boundaries.

After investigation by the governing body to determine the amount of benefit from construction of the local improvement to the lots and tracts fronting or abutting the improvement, the amount to be assessed against each lot for any local improvement for which special assessments are to be levied may be determined by dividing the total cost of the improvement by the number of feet fronting or abutting the improvement, and the quotient may be assessed per front foot upon the property fronting or abutting the improvement. If any of the property assessed is outside of municipal boundaries, the amount levied and assessed may not be collected unless the property has been annexed into the municipality.