As used in this act:

    (a) "Board" means a county board of commissioners.

    (b) "Local unit of government" means a city, village, township, or county.

    (c) "Political subdivision" means any agency or local unit of government of this state which now is, or after the effective date of this act becomes, authorized to levy taxes or empowered to cause taxes to be levied.

    (d) "Property rights" means the ownership of an easement over, or any other interest in, real property or water located in this state.

    (e) "United States" means the federal government, or any agency or instrumentality of the federal government.