The Washington Supreme Court has unanimously upheld statutory amendments enacted by the state legislature in 2003 that included certain private developers within the definition of municipal water suppliers. Lummi Indian Nation v. State, No. 81809 (Wash. 10/28/10). The decision partly reversed a 2008 district court determination that the amendments violated separation of powers. The lower court rejected an argument that the amendments also violated due process. Both sides appealed, and the state’s high court granted review.

On appeal, plaintiffs argued that the amendments, which defined private developers who provided water to more than 15 houses as municipal water suppliers, violated the due process rights of junior water rights holders. They argued that vested water rights cannot be deprived without due process of law. Plaintiffs also restated their successful argument below that the amendments violated separation of powers because, in enacting the amendments, the legislature made a determination of adjudicative facts concerning the “good standing” of particular water rights.

The Washington Supreme Court disagreed, ruling that plaintiffs had not produced a single case in which “mere potential impairment of some hypothetical person’s enjoyment of a right has been held to be sufficient for a successful facial due process challenge.” The court also rejected plaintiffs’ argument that the state legislature had overstepped its authority when it enacted the 2003 amendments, ruling that state lawmakers made the changes with deference to prior supreme court decisions that water rights represented by a water right certificate issued before September 9, 2003, for municipal supply purposes “is a right in good standing.” Dep’t of Ecology v. Theodoratus, 135 Wash. 2d 582 (1998).