Tex. Gov't Code § 1505.068

The reasonable costs of administering and operating and the reasonable expense of maintaining the project are a first lien against the revenue and income from the operation of a project, superior to the lien of any encumbrance on the project. From the revenue and income of a project, the municipality shall, monthly or more frequently if necessary, first deposit to the credit of the operation and maintenance account an amount sufficient to pay those expenses.