Tex. Water Code § 16.233

In performing functions that are a part of duties assigned to the commission or board by this code or other law, the executive director, with the approval of the commission, or the executive administrator, with the approval of the board, may confer with federal and state agencies and with political subdivisions and may execute cooperative agreements with them. The executive director or executive administrator may cancel any such agreement on 10 days notice to the other party.