The board, in making the annual assessments and levies as herein provided, shall take into account the maturing indebtedness for the ensuing year as provided in its contracts and deficiencies and defaults of prior years, and shall make ample provision for the payment thereof. In case the proceeds of such levies and assessments made under the provisions of this chapter, together with other revenues of the district, are not sufficient to pay punctually the annual installments on its contracts, and interest thereon, and to pay defaults and deficiencies, then the board shall make such additional levies of assessments against property to which water has been allotted as may be necessary for such purposes, and, notwithstanding any limitations by contract, order, or otherwise, such assessments shall be made and continue until the indebtedness of the district shall be fully paid.