## Facts

- Mason owned and operated a downstream saw and grist mill powered by a small dam and pond on a small stream.
- Hoyle owned and operated an upstream woolen mill on the same stream, with a dam and pond, and also had access to steam power.
- Historically, the stream’s flow was generally sufficient for both mills when operated in an ordinary manner, except during predictable dry seasons.
- In 1881, Hoyle enlarged his reservoir so he could close his gates and detain nearly the entire natural flow for several days to accumulate water.
- During summer low-flow periods, Hoyle commonly detained the stream for about five days to obtain enough water to run his mill by water power for roughly five hours.
- While Hoyle was filling his enlarged pond, little or no water reached Mason’s dam, stopping Mason’s mill for substantial periods.
- When Hoyle later released stored water to operate his mill, the discharge was sudden and voluminous, causing Mason’s smaller pond to overflow and sending excess water over Mason’s dam to waste, at times and rates Mason could not beneficially use.
- Mason sued, alleging that Hoyle’s detention and intermittent discharge wrongfully interfered with Mason’s riparian rights.

## Issues

1. Whether an upstream riparian owner’s multi-day detention of nearly the entire flow of a small stream to run a mill intermittently, substantially impairing a downstream mill’s operations, is a “reasonable use” of the watercourse.
2. Whether the riparian right to “use” water implies a right to “detain” it without regard to the downstream proprietor’s need for a reasonably regular flow.

## Decision

- The court affirmed judgment for Mason.
- Hoyle’s enlargement of the reservoir and practice of detaining nearly the whole stream for days during dry seasons, followed by intermittent releases that caused downstream waste, was an unreasonable and unlawful interference with Mason’s riparian rights.
- The court held that “reasonable” limits both the use of water and the detention of water; reasonableness is not measured by one owner’s business convenience alone.

## Legal Principles

- Riparian rights are correlative: each riparian owner is entitled to a reasonable use of the stream consistent with the rights of other riparian owners.
- A right to use water may imply a right to detain some water, but the detention must be reasonable in extent, timing, and manner of release.
- Reasonableness is evaluated in light of the character and capacity of the watercourse and the effect of the upstream use on downstream proprietors, not solely the upstream owner’s operational preferences.
- Detention that substantially deprives a downstream proprietor of water when needed—especially on a small stream during predictable low-flow periods—can be unreasonable even if the water is later released.

## Conclusion

The court held that an upstream proprietor may not impound nearly all flow of a small stream for several days to operate a mill intermittently when doing so materially halts downstream mill operations and later releases water in a way that largely goes to waste; “reasonable use” constrains both use and detention of the watercourse.


Mason v. Hoyle, 56 Conn. 255, 14 A. 786 (Conn. 1888)