## Facts

- The Keyses owned commercial property in Walnut Creek, California, built a store in 1956, and later leased it to their wholly owned corporation.
- Adjacent uphill land was leased to Romley, who built an ice rink and paved surrounding areas with asphalt.
- Romley installed roof downspouts that discharged rainwater onto the paved area, from which water flowed toward and onto the Keys property.
- The Keyses had previously placed excavated dirt in a berm across the rear of their property; they later removed that dirt.
- After grading and paving changes on Romley’s parcel and removal of the dirt berm on the Keys parcel, surface water began flooding and eroding the Keys property starting in January 1959.
- The Keyses attempted mitigation by digging a ditch and building a small dam, but flooding continued.

## Issues

1. What legal standard governs liability between urban adjoining landowners for alteration of surface-water drainage: rigid “civil law” or “common enemy” rules, or a reasonable-use test.
2. Whether the evidence supported injunctive relief and damages where both parties altered their land and plaintiffs’ alterations arguably contributed to the runoff path.

## Decision

- The California Supreme Court affirmed the permanent injunction barring defendants from discharging surface waters onto plaintiffs’ land in a greater quantity or different manner than would occur under natural conditions.
- The court affirmed the damages award of $4,384.78 against Romley for physical injury to plaintiffs’ property.
- The court rejected strict application of both the civil law rule and the common enemy doctrine in favor of a reasonable-use approach for urban surface-water disputes.
- Substantial evidence supported the trial court’s finding that defendants’ grading, paving, and downspout discharge unreasonably concentrated and directed runoff onto plaintiffs’ property.

## Legal Principles

- In urban surface-water disputes, adjoining landowners have correlative rights and duties; each may make reasonable use of land, but not in a way that unreasonably interferes with a neighbor’s property.
- Reasonableness is determined by weighing the gravity of harm against the utility of the conduct and considering all relevant circumstances, including feasibility of alternatives and each party’s conduct.
- Neither an upper owner’s privilege to improve land nor a lower owner’s obligation to accept drainage is absolute; liability depends on whether alterations unreasonably increase or concentrate runoff.
- Injunctive relief is proper to prevent recurring, unreasonable runoff conditions, and damages are recoverable for proven property injury caused by unreasonable discharge of surface waters.

## Conclusion

The court affirmed an injunction and damages for flooding caused by an adjoining landowner’s concentrated runoff and held that urban surface-water conflicts are governed by a fact-specific reasonable-use balancing test rather than rigid categorical doctrines.


Keys v. Romley, 412 P.2d 529 (Cal. 1966)