## Facts

- A dispute arose over competing claims to divert water from the Carson River near Dayton, Nevada, for mining-related uses.
- In 1858, Rose (predecessor to Carpenter) began a ditch project with a head sized for a large planned diversion, but after less than half a mile reduced the ditch so it carried only a small portion of the intended flow.
- In 1859, Ophir built a lower ditch tapping the river below Rose’s ditch; at that time Rose’s ditch carried only a small quantity of water.
- After 1862, Rose or his successors enlarged the Rose ditch to its original intended capacity, diverting enough water to deprive Ophir’s ditch of supply.
- Ophir contended Rose lacked reasonable diligence in completing the larger diversion and that Rose’s priority should be limited to the quantity actually carried in 1859; Carpenter claimed priority for the full enlarged capacity by relating back to 1858.

## Issues

1. In an appropriative water-right system, does priority of appropriation determine the superior right as between competing claimants?
2. Does an appropriator’s right relate back to the first step toward appropriation when completion of the diversion works is delayed without reasonable diligence?
3. Where an early ditch was built at reduced capacity and enlarged years later, is the senior priority measured by the later enlarged capacity or by the quantity actually diverted when a junior ditch was constructed?

## Decision

- The court held that, where rights are based on appropriation rather than riparian land ownership, priority of appropriation gives the superior right.
- The court held that relation-back protection during construction applies only if the appropriator prosecutes the necessary work with reasonable diligence.
- Because Rose did not pursue completion of the ditch as originally intended with reasonable diligence, Carpenter could not relate the enlarged appropriation back to 1858.
- Carpenter’s senior right was limited to the quantity of water that actually ran through Rose’s ditch in 1859 when Ophir constructed its ditch.
- Ophir’s 1859 appropriation was prior to any additional quantity claimed through the post-1862 enlargement of Rose’s ditch.

## Legal Principles

- In an appropriative regime, the first appropriator has the superior right as against later appropriators, subject to rules governing perfection of the appropriation.
- If completion of an appropriation requires construction work, the law allows a reasonable time to complete it and may protect the right by relating it back to the first step taken.
- Relation-back does not apply when the necessary work is not prosecuted with reasonable diligence; in that event, the right dates from completion or full perfection.
- Reasonable diligence requires steady, customary effort consistent with similar enterprises and a bona fide intent to complete within a reasonable time, not extraordinary exertion.
- Personal illness or lack of funds, as circumstances incident to the person rather than the enterprise, do not excuse substantial delay that would otherwise defeat relation-back.

## Conclusion

The court limited the earlier appropriator’s priority to the amount of water actually diverted when the later appropriator began use, holding that an enlarged diversion cannot relate back to an earlier start date absent reasonable diligence in completing the work.


Ophir Silver Mining Co. v. Carpenter, 4 Nev. 534 (Nev. 1869)