All moneys paid into the county treasury under the provisions of this act shall be placed in the special fund hereinbefore provided for. If at any time after the disincorporation of said district it shall be found that there is not sufficient money in the treasury to the credit of the fund hereinbefore provided, with which to pay any indebtedness of said district, said board of supervisors shall have the power, and it shall be their duty, to levy upon, and there shall be collected from, the property within the territory formerly included within said district subject to taxation for the indebtedness, a tax or taxes sufficient in amount to pay the said indebtedness as the same shall become due; such tax or taxes, assessments and collections shall be made in the same manner and at the same time that other taxes of each affected county are levied and collected, and they shall be an additional tax within said territory for the payment of said debts.