## Facts

- R.J.A., Inc. owned and operated a summer resort near the headwaters of Tahosa Creek, which flows to St. Vrain Creek and then the South Platte River.
- The property included a 27-acre peat moss marsh that had existed for about 3,000 years.
- Water entered the marsh from surface streams and springs; despite evaporation and evapotranspiration losses, remaining water moved through or around the marsh to become the headwaters of Tahosa Creek.
- In the early 1970s, R.J.A. removed peat moss and converted the marsh into a well-drained mountain meadow to reduce evaporation and evapotranspiration.
- R.J.A. claimed the project produced a net increase in streamflow and sought to appropriate that increment as a “developed water right.”
- In 1979, R.J.A. filed an application in the Water Division 1 water court asserting the claimed developed water right should not be subject to Colorado’s statutory priority system for tributary waters.
- The water court found the water was tributary to Tahosa Creek and denied the application, concluding that reduced consumptive use of tributary water could not generate a right independent of the priority system.

## Issues

1. Whether an upstream landowner who reduces evaporation and evapotranspiration from a peat marsh, thereby increasing tributary flow to a natural stream, may claim that increment as “developed water.”
2. Whether such an asserted right may exist outside the adjudication and administration-by-priority scheme established for tributary waters under Colorado’s Water Right Determination and Administration Act of 1969.

## Decision

- The Colorado Supreme Court affirmed the denial of R.J.A.’s application.
- The court held that reducing consumptive use of tributary water by altering natural conditions does not create a developed water right exempt from the statutory and constitutional priority system.
- The additional water reaching the stream remained tributary to a natural stream and therefore must be administered under the system of priorities.

## Legal Principles

- Tributary waters that are part of a natural stream system are adjudicated and administered under Colorado’s constitutionally based prior-appropriation priority system as implemented by the Water Right Determination and Administration Act of 1969.
- “Developed water” generally refers to water added to a stream system by human effort that would not otherwise have been part of the natural stream; it does not include water made available merely by reducing natural atmospheric losses from tributary water.
- A land-management project that decreases evaporation and evapotranspiration may increase the timing or quantity of tributary flow, but it does not transform that water into a separate class of water free from priority administration.
- Recognizing an exclusive, non-priority entitlement to increased tributary flow from such projects would conflict with the comprehensive statutory scheme and risk impairing senior appropriators’ reliance on the natural stream system.

## Conclusion

Colorado law does not permit an upstream landowner to claim, as developed water outside the priority system, additional tributary streamflow produced by draining or altering a peat marsh to reduce evaporation and evapotranspiration; any resulting increase remains tributary water subject to adjudication and administration by priority.


R.J.A., Inc. v. Water Users Ass'n of Dist. No. 6, 690 P.2d 823 (Colo. 1984)