If at any time after the initial acquisition or establishment by any irrigation district of an electric light and power plant, lines, or systems the Department of Natural Resources deems it to be practicable and expedient that additional plants, lines, or systems, or extensions or improvements of the existing electric light and power plant, lines, or systems, should be made by the district, and if the cost of such additions and extensions cannot be made or provided for by the application of unused funds derived from the operation of the existing electric light and power plant, lines, or systems or by the pledge or assignment of future net revenue as in sections 46-301 to 46-315, then the board of directors may, and on the petition of not less than twenty-five percent of the qualified electors of the district shall, submit to the electors of the district at any general election or at any special election called for the purpose, the question and proposition of making such improvements, additions, or extensions and the issuance of bonds of the district to pay the cost thereof. A statement of the department with reference to the expediency and feasibility of such proposed extension and addition shall be made by such department to the irrigation district whenever requested by the board of directors of such district. Such election shall be held and the result thereof determined and declared in conformity with the provisions of law governing elections upon the proposition of the issuance of bonds of the district. Complete plans and a description of the proposed additions, improvements, changes, or extensions shall be prepared and kept on file in the main office of the district or of the board of the district, subject to inspection by any elector or other interested person, at all reasonable business hours during the period of publication of notice of such election. The ballots at such election shall conform, as nearly as practicable, with the requirements of section 46-305.