Tex. Water Code § 49.505
A district that receives a petition under Section 49.503 shall compute the proportionate amount of water rights to the Rio Grande. The proportionate amount of water rights is equal to the amount of irrigable acres of land in the subdivision multiplied by the lesser of:
Added by Acts 2007, 80th Leg., R.S., Ch. 1430 (S.B. 3), Sec. 2.24, eff. September 1, 2007.