South Valley Ground Water v. ID Dept of Water Resources

Summary

The Court held that the Director had authority under Idaho Code section 42-237a.g. to initiate proceedings and curtail junior groundwater rights without a prior delivery call or formal designation of an area of common groundwater supply. It further held that the Conjunctive Management Rules and their material-injury procedures apply only when a water user makes a delivery call, although the Director must still establish actual injury supported by substantial and competent evidence and apply Idaho's prior-appropriation principles. The opinion text states that the district court's decision was affirmed in part and reversed in part; the provided text ends before the Court's complete due-process and attorney-fee analysis.