## Facts

- Frank L. and June D. MacArtor owned and lived on property in Brandywine Hundred, Delaware, using a shallow, bricked domestic well as their household water source.
- The Graylyn Crest III Swim Club, Inc. leased land across Marsh Road (about 150 feet back from the road) and built a swimming pool and related facilities.
- The club drilled a deep well of approximately 200 feet, encased in steel for the first 42 feet; the wells were about 200 feet apart.
- On July 7, 1960, the club began pumping substantial quantities of water from its well to fill the pool.
- By the next morning, the water level in the MacArtors’ shallow well had fallen below the intake pipe, making the well unusable for domestic purposes.
- Experts initially disagreed on whether the wells were hydrologically connected; by trial, the club’s expert agreed a connection existed, and the court found both wells drew from a common underground supply.
- The MacArtors sought to enjoin further use of the club’s well, restrict the club’s loudspeaker use as a nuisance, and recover $73.49 in damages.

## Issues

1. What legal standard governs competing withdrawals from percolating groundwater where one user’s pumping substantially interferes with a neighbor’s preexisting domestic well drawing from the same underground source?
2. Whether the club’s pumping and loudspeaker use constituted unreasonable interference warranting injunctive relief and damages.

## Decision

- The Court of Chancery rejected an absolute-ownership approach to percolating groundwater and adopted an objective reasonableness standard.
- Applying that standard, the court declined to grant a sweeping injunction barring the club’s continued use of its well.
- The court evaluated the loudspeaker and related nuisance allegations under reasonableness principles and granted only limited relief aimed at unreasonable aspects of the conduct.
- The court awarded, at most, modest relief consistent with the small damages claimed and the equitable balancing required by the circumstances.

## Legal Principles

- Competing rights to withdraw percolating groundwater are limited by objective reasonableness, not absolute dominion by the overlying landowner.
- Reasonableness depends on all circumstances, including the nature and purpose of the use, the extent and duration of interference, the character of the locality, and the feasibility of avoiding or reducing harm.
- Proof that wells draw from a common underground source is central to establishing causation in groundwater-interference disputes.
- Equitable remedies in groundwater and nuisance cases should be proportionate; interference does not automatically justify a complete prohibition of the challenged activity.

## Conclusion

Delaware Chancery treated groundwater withdrawal and related neighborhood impacts as matters of objective reasonableness, rejecting absolute rights in percolating water and fashioning limited, proportional relief rather than enjoining the swim club’s well use outright.


MacArtor v. The Graylyn Crest III Swim Club, Inc., 187 A.2d 417 (Del. Ch. 1963)