Here is the opinion in Lummi Indian Tribe v. State of Washington (Wash. S. Ct.).

An excerpt:

In 1998, this court held that under then-existing law, new private water rights did not fully vest until the water was put to a beneficial use, and not merely when the “pumps and pipes” capacity to use the water was built. Dep’t of Ecology v. Theodoratus, 135 Wn.2d 582, 586, 957 P.2d 1241 (1998). We cautioned then that we were not considering municipal water rights, which often receive separate treatment in water law. Id. at 594. In response to our opinion, the legislature amended the municipal water law, Second Engrossed Second Substitute H.B. 1338, 58th Leg., Reg. Sess. (Wash. 2003) (SESSHB 1338), to, among other things, explicitly define certain nongovernmental water suppliers as municipal and to make that definition retroactive. We are now asked whether these amendments violate separation of powers or facially violate due process. We conclude they do not. We reverse in part and affirm in part.