General obligation indebtedness issued pursuant to this chapter shall be payable from any sources of available funds, including revenues or taxes. The board is hereby authorized to levy and collect taxes upon all property in the district subject to taxation by the district without limitation of rate or amount for the payment of the evidences of such general obligation indebtedness and the interest thereon. Such taxes shall be in addition to all other taxes levied for district purposes and shall be levied at the same time and in the same manner as other district taxes are levied and when collected shall be deposited in a special fund and shall be used for no purpose other than the payment of the principal of and interest on such general obligation indebtedness.