## Facts

- Clear Springs Foods, Inc. and Blue Lakes Trout Farm, Inc. operated spring-fed aquaculture facilities in southern Idaho with senior surface-water rights.
- Junior groundwater users pumped from the Eastern Snake River Plain Aquifer, which is hydraulically connected to Snake River spring discharges supplying the trout farms.
- Increased junior pumping reduced spring flows and impaired the seniors’ ability to receive water under their rights.
- The seniors made delivery calls to the Idaho Department of Water Resources (IDWR) seeking administration under prior appropriation.
- After a contested case, the IDWR Director found junior pumping caused material injury to the senior rights and issued curtailment orders against certain junior users, while addressing mitigation proposals.
- On judicial review, the district court largely upheld the Director’s final orders; juniors appealed and seniors cross-appealed.

## Issues

1. Whether substantial evidence supported the Director’s finding that junior groundwater pumping caused material injury to the seniors’ spring-fed surface-water rights.
2. Whether, under Idaho’s Administrative Procedure Act, courts should defer to the Director’s technical and factual determinations in a complex hydrologic record.
3. Whether the Director acted within statutory authority in ordering curtailment (and evaluating mitigation) as a remedy under conjunctive administration.
4. Whether the administrative process and allocation of burdens in the delivery-call proceeding complied with procedural due process.
5. Whether the Director was legally required to impose additional curtailment beyond the orders entered.

## Decision

- The Idaho Supreme Court affirmed the district court judgment upholding the Director’s final orders.
- The Court held substantial evidence supported the Director’s causation and material-injury findings based on hydrologic data, modeling, and expert testimony.
- The Court held the Director had authority to administer connected surface and groundwater rights conjunctively and to require curtailment or adequate mitigation to protect seniors.
- The Court rejected the juniors’ due process and procedural challenges.
- The Court rejected the seniors’ cross-appeal seeking greater curtailment, concluding the Director was not required to order maximum curtailment so long as the remedy reasonably addressed material injury.

## Legal Principles

- Under Idaho law, hydraulically connected ground and surface waters may be administered conjunctively to enforce the prior appropriation doctrine.
- A “material injury” determination is fact-intensive and may rely on hydrologic modeling and expert evidence; it is upheld on review if supported by substantial evidence and not arbitrary, capricious, or an abuse of discretion.
- The IDWR Director has remedial discretion to select curtailment, mitigation, or related measures, provided the selected approach adequately protects senior rights in light of the record.
- In technical water-administration disputes, reviewing courts generally defer to the agency’s specialized expertise when the agency’s reasoning is supported by the evidentiary record.
- Delivery-call procedures satisfy due process when affected users receive notice and a meaningful opportunity to participate in an evidentiary hearing; requiring juniors to rebut injury or prove adequate mitigation after a prima facie showing is permissible.

## Conclusion

The court upheld conjunctive administration that curtailed junior groundwater pumping where the agency found, on substantial evidence, that pumping depleted spring flows and materially injured senior surface-water rights, and it confirmed broad agency discretion to craft remedies that address injury without mandating maximum curtailment.


Clear Springs Foods, Inc. v. Spackman, 150 Idaho 790, 252 P.3d 71 (Idaho 2011)