(a) The board may borrow money at a rate not to exceed the maximum annual percentage rate allowed by law for district obligations at the time the loan is made if the board declares that:
(1) money is not available to meet authorized obligations of the district; and
(2) an emergency exists.
(b) To secure a loan, the board may pledge:
(1) district revenue that is not pledged to pay the district’s bonded indebtedness;
(2) district taxes to be imposed by the district during the 12-month period following the date of the pledge that are not pledged to pay the principal of or interest on district bonds; or
(3) district bonds that have been authorized but not sold.