The purposes of use included in municipal priority rights are domestic, municipal, and industrial. The purposes of use included in the Class A and B priority rights are irrigation and other purposes of use, excluding domestic, municipal, industrial, nonconsumptive recreation, and hydro-electric. Unless otherwise stated in a certificate of adjudication, one acre of irrigation water right in the Lower Rio Grande will be equivalent to 2.5 acre-feet of water per annum. All Class A and B priority rights in the Lower and Middle Rio Grande which have been or will be acquired for domestic, municipal, or industrial use shall be amended to authorize the change in purpose of use and converted to receive a definite quantity of water in acre-feet per annum.
30 Tex. Admin. Code § 303.43