The board of a district issuing revenue bonds under the provisions of the Water and Sanitation District Act may authorize the issuance of the bonds by resolution adopted by the affirmative vote of two-thirds of all the members of the board at a regular or special meeting called for that purpose. At the meeting, the necessity of the issuance of the revenue bonds shall be declared and, when issued, shall be signed by the president of the board and attested by its secretary, with the seal of the district affixed to the bonds.