Tex. Water Code § 51.305

(a) The board by order shall allocate a portion of the estimated maintenance and operating expenses that shall be paid by assessment against all land in the district to which the district can furnish irrigation water through its water delivery system or through an extension of its water delivery system. This assessment shall be levied against all irrigable land in the district on a per acre basis, whether or not the land is actually irrigated.

(b) The board shall determine from year to year the proportionate amount of the expenses which will be borne by all water users receiving water delivery from the district.

(c) The remainder of the estimated expenses shall be paid by assessments, charges, fees, rentals, or deposits required of persons in the district who use or who make application to use water. The board shall prorate the remainder among the applicants for irrigation water and may consider:

(1) the acreage each applicant will plant, the crop the applicant will grow, and the amount of water per acre used for irrigation purposes; and

(2) other factors deemed appropriate by the board with respect to water used for other nonirrigation uses.

(d) A landowner of irrigable land in the district or a user of water delivered by the district for any purpose other than irrigation who disputes all or a part of a board order that determines the amount of an assessment, charge, fee, rental, or deposit may file a petition under Section 11.041. That petition filed with the commission is the sole remedy available to a landowner or user of water described by this subsection.