All acts and proceedings had prior to January 1, 1975, and all contracts, expenditures and acquisitions made prior to January 1, 1975, by any consumers power district of the state where the consumers power district jointly with others contracted for the construction, building, alteration, extension, improvements, or the leasing of any power plant or system are in all things legalized, cured, and declared valid.
SDCL 49-37-9.1