The necessity of the taking shall be determined as follows:
(1) A certificate of public convenience and necessity issued under s. 196.491 (3) shall constitute the determination of the necessity of the taking for any lands or interests described in the certificate.
(2) The petitioner shall determine necessity if application is by the state or any commission, department, board or other branch of state government or by a city, village, town, county, school district, board, commission, public officer, commission created by contract under s. 66.0301, joint local water authority under s. 66.0823, redevelopment authority created under s. 66.1333, local exposition district created under subch. II of ch. 229, local cultural arts district created under subch. V of ch. 229, housing authority created under ss. 66.1201 to 66.1211 or for the right-of-way of a railroad up to 100 feet in width, for a telegraph, telephone or other electric line, for the right-of-way for a gas pipeline, main or service or for easements for the construction of any elevated structure or subway for railroad purposes.
(3) In all other cases, the judge shall determine the necessity.
(4) The determination of the public service commission of the necessity of taking any undeveloped water power site made pursuant to s. 32.03 (3) shall be conclusive.