Purpose and Need:

The Fryingpan River, located west of Basalt, Colorado, is widely known for its Gold-Medal trout
fishery and stunning scenic beauty. Ruedi Reservoir impounds the Fryingpan River 15 miles
upstream of Basalt. Water releases out of Ruedi Reservoir support a renowned trout fishery,
hydropower generation for the City of Aspen, and water supply for downstream municipalities
and agricultural water users. Constraints on water availability and the timing of inflows to the
reservoir make it difficult to manage releases to optimally support each downstream use at all
times of the year. This is particularly true in dry years. In times of water scarcity, water stored in
Ruedi Reservoir is primarily used to deliver water for irrigated agriculture and habitat
requirements for Threatened & Endangered fish species on the Colorado River near Grand
Junction. In these years, modification of the Fryingpan River’s hydrological regime can be
significant.

Reservoir operations in the summer of 2018 highlighted the need for a more strategic approach
to managing releases from Ruedi Reservoir. Recent dialog between Roaring Fork Conservancy
(RFC), the Ruedi Water and Power Authority (RWAPA), City of Aspen (Aspen), Colorado
Water Conservation Board (CWCB), Colorado River Water Conservation District (River
District), and the Bureau of Reclamation (USBR) resulted in a commitment from all parties to
participate in ongoing cooperative dialog about optimization of water releases to support
multiple uses. RFC requires assistance characterizing optimal water management approaches for
supporting aquatic life across seasons and different hydrological year types.

The tools presented here will help ensure that RFC is well-positioned to advocate for river health
needs on the Fryingpan River. This report includes:

1) a summary previous studies linking streamflow to ecosystem health,
2) a conceptual model linking hydrological characteristics to specific ecosystem functions or variables, and
3) a pair of ecological decision support tools that aim to support RFC’s advocacy for maintenance and protection of aquatic and riparian
ecosystems.

The decision support tools developed and presented here aim to encourage dialog
between RFC, RWAPA, Aspen, CWCB, the River District, and USBR in a way to produce a
more informed water management decision-making process on the Fryingpan River across year
types and into an uncertain future where climate change-induced alteration of regional hydrology
may necessitate new operational strategies and release schedules for Ruedi Reservoir.