The special district may borrow money and incur indebtedness in anticipation of the sale of bonds which have been authorized to be issued by the voters within the special district but which have not been sold and delivered, and it may issue bonds, notes, or other securities as provided in this article by action of the board and without the necessity of calling and holding an election. Such evidences of indebtedness shall constitute general obligations of the district. The indebtedness may be incurred for any of the purposes for which a bond issue had previously been approved by the voters, and to reimburse the district for expenditures incurred for any of such purposes. The indebtedness incurred under this article shall be evidenced by bonds, notes or other evidences of indebtedness maturing in not to exceed five years from their date, shall bear interest at such rate or rates as may be fixed by the board, and may be issued and sold at public sale as the board may direct. All other terms and conditions of such evidences of indebtedness shall be fixed by the board. The maximum principal amount of all indebtedness outstanding under this article shall not at any time exceed the aggregate amount of bonds which the district is then authorized to issue, less the amount of other securities then outstanding issued in anticipation of the sale of such an authorized issue.