## Facts

- The Herminghaus family owned approximately 18,000 acres of riparian land along about twenty miles of the San Joaquin River in Fresno and Madera Counties.
- The land historically benefited from the river’s natural seasonal pattern, including high spring flows that overflowed onto low-lying areas, depositing silt and moisture used for irrigation, grazing, and agricultural enrichment.
- Southern California Edison Company owned upstream lands and planned and partially built dams, reservoirs, and hydroelectric works to store and divert substantial river flows.
- The project would regulate and reduce seasonal high waters that ordinarily reached and overflowed onto plaintiffs’ riparian lands.
- Plaintiffs alleged the impoundment and diversion would prevent water from reaching and flowing across their lands in its ordinary course, impairing their riparian use and causing irreparable harm.

## Issues

1. Whether downstream riparian owners have a vested right to the natural and ordinary flow of the stream, including customary seasonal high waters and overflows used to irrigate and enrich riparian lands.
2. Whether an upstream appropriator’s proposed storage and diversion for hydroelectric generation may be enjoined when it would materially diminish or alter that natural flow.
3. Whether plaintiffs’ use of seasonal floodwaters by allowing overflow across their lands is “wasteful” or “unreasonable” so as to limit riparian protection.

## Decision

- The California Supreme Court affirmed the trial court’s judgment for plaintiffs.
- The court upheld an injunction restricting Edison’s storage and diversion to the extent necessary to prevent impairment of plaintiffs’ riparian rights.
- The court held plaintiffs’ riparian rights included the benefit of the river’s natural seasonal variations, including high waters and customary overflows.
- The court rejected the argument that plaintiffs’ overflow-based use was legally “wasteful” such that upstream storage could proceed notwithstanding resulting impairment.

## Legal Principles

- Riparian rights are vested property rights incident to ownership of riparian land.
- A riparian owner is entitled to have the stream flow in its natural and ordinary course, including natural seasonal variations that historically irrigate and enrich the riparian land.
- Appropriative uses are subordinate to preexisting riparian rights and may be enjoined when they materially diminish or alter the natural flow reaching riparian land.
- A court may grant injunctive relief to prevent interference with riparian rights even if the upstream project is economically beneficial and appears more efficient in water use.
- A downstream riparian’s long-established use of seasonal overflow to irrigate and enrich riparian land is a protected beneficial use, not defeated merely by labeling it “waste.”

## Conclusion

The court treated the downstream owners’ reliance on the San Joaquin River’s ordinary and seasonal high flows as a protected riparian property right and affirmed injunctive relief barring upstream storage and diversion that would materially alter those flows, notwithstanding the asserted public utility of hydroelectric development.


Herminghaus v. S. Cal. Edison Co., 200 Cal. 81, 252 P. 607 (Cal. 1926)