SDCL § 9-40-4: Utility facilities outside municipal limits.

Every municipality may procure a supply of water, electricity, or gas and may dispose of sewage outside its corporate limits, and for such purposes may construct, operate, and maintain outside its corporate limits, as a part of any such system, dams, reservoirs, intakes, spillways, conduits, or other devices to gather and store surface, flood, or other waters, pipelines, poles, wires, and cables for the transmission of water, electric current, and gas, and sewer mains, outlets, and treatment and disposal plants.