The board of directors of the metropolitan utilities district shall have general charge, supervision, and control of all matters pertaining to the natural gas supply and the water supply of the district for domestic, mechanical, public, and fire purposes. This shall include the general charge, supervision, and control of the design, construction, operation, maintenance, and extension or improvement of the necessary plant to supply natural gas, to develop power, and to pump water. It shall have the authority to enter upon and utilize streets, alleys, and public grounds therefor upon due notice to the proper authorities controlling same, subject to the provisions of sections 39-1361 and 39-1362, except that while any permit hereafter granted by the Department of Transportation under such provisions shall not be construed to be a contract as referred to within the provisions of section 39-1304.02, such parties may separately contract in relation to relocation of facilities and reimbursement therefor. The board shall also have the power to appropriate private property required by the district for natural gas and water service, to purchase and contract for necessary materials, labor, and supplies, and to supply water and natural gas without the district upon such terms and conditions as it may deem proper. The authority and power conferred in this section upon the board of directors shall extend as far beyond the corporate limits of the metropolitan utilities district as the board may deem necessary.