Tex. Water Code § 54.510

(a) In the orders or resolutions authorizing the issuance of bonds, including refunding bonds, the board may provide for the flow of funds, the establishment and maintenance of the interest and sinking fund, the reserve fund, and other funds, and may make additional covenants with respect to the bonds and the pledged revenues and the operation and maintenance of those works, improvements, plants, facilities, equipment, and appliances the revenue of which is pledged, including provisions for the operation or for the leasing of all or any part of the improvements and the use or pledge of money derived from the operation contracts and leases, as the board may consider appropriate.

(b) The orders or resolutions of the board authorizing the issuance of bonds may also prohibit the further issuance of bonds or other obligations payable from the pledged revenue or may reserve the right to issue additional bonds to be secured by a pledge of and payable from the revenue on a parity with or subordinate to the lien and pledge in support of the bonds being issued, subject to the conditions which may be set forth in the orders or resolutions.

(c) The orders or resolutions of the board issuing bonds may contain other provisions and covenants as the board may determine, not prohibited by the Constitution or by this chapter.

(d) The board may adopt and cause to be executed any other proceedings or instruments necessary and convenient in the issuance of bonds.