## Facts

- Central Power Company held an 1882 appropriative right on the Platte River system for a minimum flow of 162 cubic feet per second at the head of the Kearney Canal for irrigation and power generation.
- Upstream irrigators held junior appropriations on the North Platte and Platte Rivers and diverted water before it reached the Kearney Canal headworks.
- The Platte River’s “broad and shallow” channel produced major transit losses from evaporation, seepage, and channel conditions as water moved downstream.
- Evidence indicated that roughly 700 cubic feet per second at the upstream measuring point could be necessary to deliver 162 cubic feet per second at the Kearney Canal headgate.
- During certain periods, natural flow was so low that no meaningful amount of water would reach the Kearney Canal even if all junior diversions were stopped.
- Irrigators and Central sought a writ of mandamus compelling state irrigation officials to protect Central’s senior priority by curtailing junior diversions whenever Central did not receive 162 cubic feet per second.
- The district court denied mandamus and dismissed the petition; the relators appealed.

## Issues

1. Whether state irrigation officials had a clear, ministerial duty enforceable by mandamus to curtail junior appropriators whenever a senior appropriator was not receiving its full decreed flow.
2. Whether officials may refuse to enforce a senior “call” when, due to natural transit losses and hydrologic conditions, curtailing juniors would not result in a substantial, usable delivery to the senior appropriator.

## Decision

- The Nebraska Supreme Court affirmed the denial of mandamus.
- The court held mandamus would not compel officials to shut down junior diversions during periods when doing so would not deliver usable water to the senior right because of natural losses and physical conditions.
- The court treated the administration decision as involving technical judgment and discretion rather than a purely ministerial act.
- The relators failed to show that, for the relevant periods, curtailing juniors would have produced a substantial, beneficial flow at the Kearney Canal headgate.

## Legal Principles

- Mandamus lies only to compel performance of a clear, present, ministerial duty; it does not control discretionary administrative judgment.
- Prior appropriation governs relative priority, but enforcement is constrained by beneficial use and avoidance of waste; an appropriator has no right to demand enforcement that would waste water.
- Water administrators may consider physical possibility and whether curtailment of juniors would provide a substantial, usable benefit to the senior appropriator.
- Statutory duties to administer priorities are conditioned on hydrologic realities; when delivery to the senior is physically impossible, a duty to curtail juniors is not shown with the clarity required for mandamus.

## Conclusion

The court refused to compel priority enforcement by mandamus where river conditions made delivery to the senior right effectively impossible, holding that water administration may account for beneficial use and waste prevention and that such fact-dependent decisions rest within administrative discretion absent a clear, ministerial duty.


State ex rel. Cary v. Cochran, 138 Neb. 163, 292 N.W. 239 (1940)