## Facts

- The Mud Lake area in Jefferson County, Idaho is a terminal basin with no natural drainage outlet, consisting of a diked lake and adjacent low-lying farmland.
- Unusually heavy spring rain in 1984, combined with an already high water table, raised concern that the Mud Lake dike could fail and flood thousands of acres, threatening life and property.
- The county board of commissioners, state and local agencies, canal companies, water users, and others coordinated emergency flood-control efforts to reduce the risk of catastrophic dike failure.
- Emergency measures included strengthening the dike, diverting excess water, and capping certain wells that flowed into the lake.
- In April 1984, farmland owned by Joe Marty and other plaintiffs began to flood; water remained standing on their properties through the year.
- In June 1984, the county commissioners and the Governor declared a state of emergency.
- The plaintiffs’ lands flooded again in 1985.
- The plaintiffs sued multiple defendants, including the State of Idaho, Flood Control District No. 5, Water District No. 31, various officials, canal companies, and water-user organizations.
- The plaintiffs alleged that defendants’ flood-control actions and decisions—especially holding water in the basin and not building a spillway or outlet that would have prevented flooding on plaintiffs’ lands—caused or worsened the flooding and damaged their property.
- The plaintiffs asserted claims including trespass, negligence, strict liability, inverse condemnation under the Idaho Constitution, and requests for injunctive relief.
- The defendants sought summary judgment. As to inverse condemnation, the government argued it was protected by the public-necessity doctrine because the actions were taken during an emergency to protect the public.
- The trial court granted summary judgment for all defendants on all claims and denied injunctive relief. The plaintiffs appealed.

## Issues

1. Whether the governmental defendants were immune from liability on the plaintiffs’ tort claims arising from emergency flood-control actions and decisions.
2. Whether the plaintiffs could pursue an inverse-condemnation claim for alleged taking or damaging of property despite the defendants’ reliance on public necessity.
3. Whether the canal companies and water-user organizations breached any duty owed to the plaintiffs related to the flooding.
4. Whether the trial court properly denied the plaintiffs’ request for injunctive relief.

## Decision

- The Idaho Supreme Court affirmed summary judgment for the governmental defendants on the plaintiffs’ tort claims based on governmental immunity.
- The Court affirmed summary judgment for the canal companies and water users, concluding the record did not show a breach of any duty owed to the plaintiffs to prevent the flooding.
- The Court affirmed the denial of injunctive relief.
- The Court reversed summary judgment against the plaintiffs on their inverse-condemnation claim and remanded for further proceedings.

## Legal Principles

- Governmental entities may be immune from tort liability for actions and decisions made in responding to flood threats and emergencies, including policy-level choices about flood-control measures.
- Summary judgment is appropriate on tort theories (such as negligence, trespass, and strict liability) when statutory or discretionary-function immunity applies to the challenged governmental conduct.
- Private canal companies and water-user groups are not liable in tort on this record absent proof that they owed a duty to the plaintiffs to prevent flooding and that they breached that duty.
- Injunctive relief is discretionary; a trial court may deny an injunction where the record does not justify a continuing judicial order directing flood-control operations.
- An inverse-condemnation claim is distinct from tort liability: if government action results in a taking or damaging of private property for public use, the Idaho Constitution may require compensation even when tort remedies are barred.
- The public-necessity doctrine, even in an emergency, does not automatically defeat an inverse-condemnation claim at the summary-judgment stage where factual questions remain about whether government conduct caused a compensable invasion of private property.

## Conclusion

In Marty v. State of Idaho, the Idaho Supreme Court upheld summary judgment on tort and injunctive claims arising from the 1984–85 Mud Lake flooding because governmental immunity barred tort recovery and the record showed no duty breach by canal companies or water users, but it reversed summary judgment on inverse condemnation, holding the landowners could proceed with a constitutional compensation claim despite the government’s public-necessity argument.


Marty v. State of Idaho, 786 P.2d 524 (1989)