The recently released Yampa River Scorecard Project grade of C-plus for the upper segment of the Yampa River shows a need for some improvements for overall river health in the stretch between Stillwater and Stagecoach reservoirs.

Jenny Frithsen, environmental program manager at Friends of the Yampa, oversees the long-term river health monitoring and evaluation project. Frithsen said a major reason for the lower score is because that river segment is heavily utilized by agricultural water users but has less water coming in from smaller tributaries compared with downstream sections of the river.

“The first and foremost contributor to river health is water in the river, and the Upper Yampa and the Bear River are arguably the hardest-working and most heavily administered sections of river in the Yampa River system,” Frithsen said. “It probably is no surprise that the flow regime has lower scores for our ecological river health assessment. It is an altered flow regime.”

This is the third year nonprofit Friends of the Yampa has released a grade for river segments as part of a five-year evaluation of five Yampa River segments from the Flat Tops Wilderness to Dinosaur National Monument.

The Middle Yampa section from Hayden Pump Station to South Beach downstream of Craig scored a B following a 2022 study. The Steamboat Springs segment from the Stagecoach Reservoir tailwaters to the Hayden Pump Station scored a B-minus from data collected in 2023.

Frithsen presented a high-level overview of the 2024 river study segment during a South Routt Water Users meeting Monday evening at Soroco High School. The study looks at 45 indicators and nine characteristics of river health to determine and issue a score for combined flow and sediment regime, water quality, habitat and riverscape floodplain connectivity, riparian condition, river form, structural complexity and biotic community.

On the positive side, the study team found the Upper Yampa stretch rated good in water quality, structural complexity, beaver activity, channel morphology and invasive weeds. The healthy beaver activity, especially on U.S. Forest Service land, showcases the natural engineering work of the large rodents to help mitigate the impacts of human water use and infrastructure. The beavers’ work maintains minimum flows in late summer and fall and provides a refuge for fish during low flows.

On the “not-so-good” side, the Upper Yampa segment suffers from impacted riverscape connectivity and reduction in riparian buffers.

“In many places the river is channelized and does not have great connection to its floodplain,” Frithsen explained. “The riparian condition, in many places along the river, we saw that riparian trees and shrubs had been replaced with mountain meadow hay.”

Although productive mountain meadow hay fields may filter runoff, improve water quality and sequester carbon pollution, hayfields adjacent to the river “are not doing much to help issues of erosion that could be helped by more robust riparian buffer zones,” Frithsen said.

Frithsen noted macroinvertebrates in the stretch have room for improvement to become a more robust population distribution.

“We are seeing more pollution-tolerant species and fewer pollution-sensitive species, which is a reflection on the water quality and the habitat,” she explained.

The Upper Yampa segment study documented the heavily impacted river flow patterns of minimal and peak flows, which relates to a river section with two large agricultural reservoirs, Stillwater and Yamcolo, and many irrigation diversion ditches.

“Low flows are impacted by reservoir management, diversions, water rights administration, things that you would expect,” Frithsen said. “Diversion infrastructure in places can limit aquatic connectivity upstream and downstream. Riverscape connectivity, which is a huge driver of ecological river health, is compromised in places.”

The scorecard project was recommended by the Yampa Integrated Water Management Plan through the Yampa-White-Green Basin Roundtable.The project aims to produce a dataset that can be used to track changes over time and help inform and educate community members, landowners and river managers on principles of river health. The study information is collected through field work, surveys and existing data from multiple sources.

Friends of the Yampa will collect data this summer in the Elk River segment of the river basin from Seedhouse Road to east of Milner. The study will move to the Lower Yampa segment in 2026, from west of Craig to Deer Lodge Park where the Little Snake River intersects the Yampa. Then the five-year study cycle will start again.

Emily Burke, Friends of the Yampa conservation program manager, said the next step in the continuing study is the introduction of the Yampa River Stewardship Program, orYStew, which is a partnership with nonprofit Community Agricultural Alliance and other local nonprofits. The program aims to help landowners with river restoration projects and land management practices that support river health and improved future scorecard grades. Later this year, YStew will offer technical assistance, funding options and workshop trainings.