Nothing in this chapter or chapter 5-18A, 5-18B, 5-18D, or 5-21 may be so construed as to prevent counties or townships from constructing or maintaining the county highway system and any secondary highways by means of drags, road planers, tractors, and other approved mechanical devices owned by said counties or townships. Nothing in this chapter or chapter 5-18A, 5-18B, 5-18D, or 5-21 may be construed to prevent the construction of dams in connection with water conservation projects if the cost of materials used does not exceed the total cost of twenty-five hundred dollars.
SDCL 5-18C-5