Whenever it shall be necessary for or in connection with any improvement or work authorized by this act, to enter upon any public property, or property held for any public use, or acquire any easement or rights therein, such sanitary district shall have the power so to do, and when necessary for such purpose may avail itself of any Eminent Domain laws of this state, and may enter upon, use, widen, elevate, and improve any street, highway, wharf, levee, or other property, necessary in furtherance of said purposes: Provided, the former use of any such public property, or property devoted to public use, shall not be unnecessarily interrupted or interfered with.