Real property which would be exempt from taxation under this act if the property was used by the lessor and which is leased, loaned, or otherwise made available to a municipal water authority created under Act No. 196 of the Public Acts of 1952, being sections 124.251 to 124.262 of the Michigan Compiled Laws, whose members consist solely of a political subdivision, a combination of political subdivisions, or a combination of 1 or more political subdivisions and the state, and which is used to carry out a public purpose itself or on behalf of a political subdivision, a combination of political subdivisions, or a combination of 1 or more political subdivisions and the state is exempt from taxation under this act.