30 Tex. Admin. Code § 293.55
Tax anticipation notes may be issued by districts solely in the manner and for the purposes described in Water Code, § 49.154, as amended. No tax anticipation notes shall be redeemed in whole or in part, out of the proceeds of a district bond issue or one or more refunding tax anticipation notes, bond anticipation or revenue notes. Such notes may bear interest as provided by law; shall mature within one year of their date of issuance; shall not be renewable or subject to extension of their maturity or redeemable or refundable out of or exchangeable for additional tax anticipation notes; and shall be secured by and paid solely out of the proceeds of taxes to be levied and collected by the district in the 12-month period succeeding their date of issuance.
30 Tex. Admin. Code § 293.55