Tex. Const. art. III, § 49-d-1

(a) The Texas Water Development Board may issue Texas Water Development Bonds as authorized by constitutional amendment or by a debt proposition under Section 49 of this article to provide grants, loans, or any combination of grants and loans for water quality enhancement purposes as established by the Legislature to political subdivisions or bodies politic and corporate of the State of Texas, including municipal corporations, river authorities, conservation and reclamation districts, and districts created or organized or authorized to be created or organized under Article XVI, Section 59, or Article III, Section 52, of this Constitution, State agencies, and interstate agencies and compact commissions to which the State of Texas is a party, and upon such terms and conditions as the Legislature may authorize by general law. The bonds shall be issued for such terms, in such denominations, form and installments, and upon such conditions as the Legislature may authorize.

(b) The Texas Water Development Fund shall be used for the purposes heretofore permitted by, and subject to the limitations in this Section and Sections 49-c and 49-d; provided, however, that the financial assistance may be made subject only to the availability of funds.