At the time and place set for the hearing and consideration of the petition, it shall be the duty of the county board to ascertain (1) whether proper notice of the hearing has been given to the signers of the petition, the director, and the landowners in the district as required by section 46-1004 ; (2) whether lands within the area defined in the petition are without an adequate water supply; (3) whether the construction and maintenance of ponds, reservoirs, pipelines, wells, check dams, pumping installations, or any other facility for the storage, transportation, or utilization of water or the construction and maintenance of any combination of such proposed projects are necessary for the improvement of the area. The county board shall make no affirmative finding that any proposed project is necessary if the construction and maintenance of such project would encourage the cultivation of lands which are submarginal and which should be devoted to other uses in the public interest. The county board shall make no affirmative finding that any proposed project is necessary unless the director has approved such project; (4) whether such improvement or works will be conducive to and will tend to promote the public health, convenience, and welfare; and (5) whether the boundaries of the proposed district lie within five miles of any incorporated city or village and whether approval for incorporation of the district has been given by the governing body of such city or village. If upon such consideration it is found that such petition is in conformity with the requirements of sections 46-1001 to 46-1020, the county board shall thereupon immediately declare the district within the boundaries defined in the petition to constitute a public corporation and to be incorporated as a rural water district under the name of Rural Water District No. ……, ………. County, Nebraska (inserting number in order of incorporation and name of county) and thereupon shall enter upon its records full minutes of such hearing, together with a declaration that thenceforth such district shall constitute a body politic and corporate under such corporate name for the purposes of sections 46-1001 to 46-1020.