1. The board shall have the power to construct and maintain works and establish and maintain facilities across or along any public street or highway, and in, upon or over any vacant public lands, which public lands are, or may become, the property of the State of Nevada, and to construct works and establish and maintain facilities across any stream of water or watercourse.
2. The board shall promptly restore any such street or highway to its former state of usefulness as nearly as may be, and shall not use the same in such manner as to impair completely or unnecessarily the usefulness thereof.