A metropolitan municipal corporation shall have the power to perform any one or more of the following functions, when authorized in the manner provided in this chapter:
(1) Metropolitan water pollution abatement.
(2) Metropolitan water supply.
(3) Metropolitan public transportation.
(4) Metropolitan garbage disposal.
(5) Metropolitan parks and parkways.
(6) Metropolitan comprehensive planning.
[ 1974 ex.s. c 70 § 3; 1965 c 7 § 35.58.050. Prior: 1957 c 213 § 5.]