S.D. Codified Laws § 49-34A-46
Any electric utility with facilities within the boundaries of a municipality, as they exist from time to time, which has a municipally owned electric system serving over fifty percent of the customers in the municipality, may, at the option of the municipality, pay to the municipality an amount to be agreed upon by the electric supplier and the governing body of the municipality. If the parties have not agreed on the amount on or before May first following the calendar year from which the amount is to be paid, the amount to be paid shall be four percent of the total gross revenue collected by the electric supplier from the sale of power delivered to structures and electric service outlets situated within the municipality during the year for which the amount is paid. The tax imposed by a municipality pursuant to this section may be passed on to the purchaser. Any revenue received by the electric utility from the tax imposed by a municipality pursuant to this section that is separately stated on the invoice, bill of sale, or similar document is not considered gross receipts as defined in chapter 10-45, 10-46, or 10-52.
SDCL 49-34A-46