The right of eminent domain for the purpose of appropriating real estate is hereby extended to all corporations that are now or that may hereafter be incorporated under the laws of this state, or of any state or territory of the United States and doing business in this state, for the purpose of conveying water by ditches, flumes, pipe lines, tunnels or any other means for the utilization of water power: PROVIDED, HOWEVER, That said right of eminent domain shall not be exercised in respect to any residence or business structure or structures.