## Facts

- Kansas, Nebraska, and Colorado are parties to the Republican River Compact, a congressionally approved interstate compact allocating the Basin’s “virgin water” (49% Nebraska, 40% Kansas, 11% Colorado).
- Kansas alleged that Nebraska’s groundwater pumping for irrigation depleted stream flows and reduced deliveries into Kansas in violation of the Compact.
- Prior litigation resulted in a decree approving the 2002 Final Settlement Stipulation (FSS), which adopted technical Accounting Procedures to measure each state’s beneficial consumptive use, including stream-depleting groundwater pumping.
- The FSS and Accounting Procedures also excluded “imported water” (water brought into the Basin by human activity) from compact accounting.
- After the first full post-settlement accounting period, Kansas brought an original action seeking relief for Nebraska’s overuse during compact years 2005–2006 and sought monetary and injunctive remedies to secure future compliance.
- Nebraska conceded overuse in 2005–2006 but argued the Accounting Procedures misattributed certain imported water to it and sought equitable reformation of the procedures.
- A Special Master found Nebraska exceeded its 2005–2006 allocation by 70,869 acre-feet, characterized the breach as knowing, recommended compensatory damages plus partial disgorgement, recommended no injunction, and recommended reformation to correct imported-water treatment.

## Issues

1. Whether Nebraska violated the Republican River Compact, as implemented by the FSS and Accounting Procedures, by over-consuming its allocation in 2005–2006.
2. If Nebraska breached, whether the Court could and should award compensatory damages and partial disgorgement, and whether injunctive relief was warranted.
3. Whether the Court should equitably reform the Accounting Procedures to correct treatment of imported water while implementing the Compact decree.

## Decision

- The Court held Nebraska knowingly failed to comply with the Compact and over-consumed its allocation in 2005–2006 by 70,869 acre-feet.
- The Court awarded Kansas $5.5 million: $3.7 million in compensatory damages and $1.8 million in partial disgorgement of Nebraska’s gains.
- The Court denied injunctive relief because Kansas did not show a cognizable danger of recurrent violation.
- The Court reformed the Accounting Procedures to correct imported-water treatment so that only the Basin’s own water supply is apportioned in compact accounting going forward.

## Legal Principles

- Interstate compacts approved by Congress have the force of federal law and are enforceable in the Supreme Court’s original jurisdiction.
- In an original-jurisdiction compact dispute, the Court may apply equitable and contract-based remedies, including partial disgorgement, when a state knowingly breaches to obtain more than its share.
- Disgorgement may be used to prevent a breaching party from profiting from an opportunistic breach and to deter future violations, and it may be calibrated as partial rather than total.
- Injunctive relief in this setting requires a forward-looking showing of a cognizable danger of recurrent violation; past breach alone is insufficient.
- While a compact’s substantive allocation cannot be unilaterally altered, the Court may equitably reform decree-implemented accounting methodologies to correct serious inaccuracies and to enforce the compact’s intended apportionment (including exclusion of imported water).

## Conclusion

The Supreme Court found Nebraska knowingly exceeded its Republican River Compact allocation and ordered both compensation and partial disgorgement, declined to impose an injunction absent a demonstrated risk of recurring violations, and reformed the compact’s accounting methods to ensure that imported water is excluded and only Basin water is apportioned.


Kansas v. Nebraska & Colorado, 574 U.S. 445 (2015)