159.43 Liberal construction.—Part II of this chapter, being necessary for the prosperity and welfare of the state and its inhabitants, shall be liberally construed to effect the purposes thereof; shall be, and be deemed, authority in addition to, and shall provide alternative methods for, any other authority provided by law for the same or similar purposes; and is supplemental to and not in derogation of any powers of any local agency otherwise conferred. The criteria and requirements of this part are applicable only to projects financed under authority of this part, except as otherwise expressly incorporated by references in other provisions of law.