Such reclamation districts may contract indebtedness for strictly district purposes in excess of the amount specified in the preceding section, but not exceeding in amount, together with existing indebtedness, two and one-half percent of the value of the taxable property, as the term "value of the taxable property" is defined in RCW
39.36.015, whenever three-fifths of the voters therein voting at an election held for that purpose assent thereto. Elections shall be held as provided in RCW
39.36.050.