The board may sell the bonds from time to time in such quantities as may be necessary and most advantageous, to raise the money for the construction of the ditches and works, the acquisition of rights-of-way and property, and otherwise to fully carry out the objects and purposes of sections 31-301 to 31-369. Before making any sale the board shall at a meeting, by resolution, declare its intention to sell a specified amount of the bonds, and the day and hour and place of such sale, and shall cause such resolution to be entered in the minutes, and notice of the sale to be given by publication thereof at least twenty days in a daily newspaper published in the city of Lincoln, and in any other newspaper, at its discretion. The notice shall state that sealed proposals will be received by the board at its office, for the purchase of bonds until the day and hour named in the resolution. At the time appointed the board shall open the proposals and award the purchase of the bonds to the highest responsible bidder, and may reject all bids; but the board shall in no event sell any of the bonds for less than par.