## Facts

- Farrell and Warren owned and operated water-powered mills downstream on Forge Stream, relying on Forge Pond as a mill pond.
- The mills (or their predecessors) had used the stream’s flow for about fifty years as an established water-power source.
- Richards owned upstream riparian land along the same stream.
- Around 1876, Richards built a dam and ditch on his land to divert a substantial portion of the stream to irrigate cranberry bogs.
- After the diversion began, the flow reaching Forge Pond materially decreased, reducing the mills’ water-power and productive capacity.
- Farrell and Warren filed an equity action seeking an injunction and a declaration that the diversion works were a nuisance interfering with their riparian rights.

## Issues

1. Whether an upstream riparian owner may divert water for irrigation in a manner that materially diminishes the stream’s flow and substantially impairs a downstream mill’s long-established water-power.
2. Whether large-scale irrigation diversion constitutes an unreasonable riparian use when it significantly interferes with downstream beneficial use.
3. Whether the impairment of downstream water-power by a continuing upstream diversion warrants injunctive relief in equity as a private nuisance.

## Decision

- The Court of Chancery ruled for Farrell and Warren.
- The court held Richards could not divert the stream so as to materially diminish the quantity of water reaching the downstream mills and substantially impair their water-power.
- The court treated the dam and ditch diversion as an unreasonable riparian use and a private nuisance as against the downstream owners’ rights.
- The court granted injunctive relief restraining continued diversion that injured the mills’ water-power.

## Legal Principles

- Riparian proprietors share a common right to the natural flow of a watercourse, subject only to reasonable use by other riparian owners.
- A riparian use becomes unlawful when it materially diminishes the stream’s quantity (or otherwise sensibly impairs the stream’s usefulness) for downstream riparian owners.
- Irrigation diversion is not categorically barred, but it is impermissible when carried out on a scale that substantially interferes with established downstream uses such as mill water-power.
- Substantial, ongoing interference with riparian rights may be treated as a private nuisance in equity.
- Injunction is appropriate where the wrong is continuing and damages are inadequate due to recurrence and measurement difficulties.

## Conclusion

The court enjoined an upstream owner’s irrigation diversion because it materially reduced the stream’s flow and substantially impaired a downstream mill’s long-established water-power, making the diversion an unreasonable riparian use and an enjoinable private nuisance.


Farrell v. Richards, 30 N.J. Eq. 511 (N.J. Ch. 1879)