Neither this chapter nor anything herein contained is or shall be construed as a restriction or limitation upon any powers which the authority might otherwise have under any laws of this state, and this chapter is cumulative to any such powers. This chapter does and shall be construed to provide a complete, additional, and alternative method for the doing of the things authorized thereby and shall be regarded as supplemental and additional to powers conferred by other laws.
SDCL 11-11-183