(a) At the time general obligation bonds are issued by the district under Section 1031.201, the board shall impose an ad valorem tax at a rate sufficient to create an interest and sinking fund to pay the principal of and interest on the bonds as the bonds mature.
(b) The tax required by this section together with any maintenance and operation tax the district imposes may not exceed the tax rate approved by the voters at the election authorizing the imposition of the tax.