Texas Government Code - GOV'T § 1477.056. Amount of Tax

(a) If bonds issued under this subchapter are to be secured by a tax, the commissioners court shall impose a tax sufficient to pay the interest on the bonds as the interest accrues and the principal as the principal matures.

(b) The order authorizing the issuance of bonds may provide that the amount of tax to be collected each year may be reduced to the extent money is available from pledged project revenue for the payment of interest and principal.