Low Flows and Hot Trout: Dealing with the Effects of Climate Change in the Clark Fork Watershed

Created: 3/30/2011 - Updated: 3/02/2020


The Clark Fork watershed extends from Butte, MT to Sandpoint, ID and drains nearly the entire western portion of Montana. Based on decades of data and observations, it is clear that the Clark Fork River basin is already experiencing changing climate conditions including droughts, increased wildfires, decreased snowpack, shrinking glaciers, and early runoff. In response, the Clark Fork Coalition wrote a report, Low Flows Hot Trout: Climate Change in the Clark Fork Watershed, examining likely climate change impacts in the watershed and offering strategies to adapt to these impacts that range from individual actions to larger-scale policy changes.


The Clark Fork Coalition is a non-profit organization located in Missoula, Montana. The organization is dedicated to protecting and restoring the Clark Fork River basin, a 22,000-square-mile area that extends from Butte, MT to Sandpoint, ID. Founded in 1985, the Clark Fork Coalition dedicates a large share of its program work to watershed restoration, including planting and restoring riparian vegetation, fixing degraded and disconnected creeks and streams, restoring eroding streambanks, removing fish passage barriers, and working with landowners to keep water in streams. In late 2007 they began working on researching climate change impacts and adaptation strategies for the basin.

Climate change impacts in the Clark Fork basin include a 1-2˚C increase in average temperature, longer growing season, changes in seasonal patterns of temperature and precipitation, shrinking spring snowpack and earlier spring runoff, melting glaciers, and declining river flows. These impacts are predicted to lead to a myriad of effects including an increase in major wildfires and length of the fire season, a 5-30% decrease in trout habitat leading to decreased numbers of sensitive species such as bull trout, declining water-dependent bird populations, loss of whitebark pine, and shifts in geographic distributions and behaviors of organisms.  


In July 2008, the Clark Fork Coalition, in partnership with the National Wildlife Federation, published Low Flows Hot Trout: Climate Change in the Clark Fork Watershed, which examined climate change impacts in the Clark Fork watershed and developed strategies to adapt to these impacts. The report was funded through several different mechanisms including government grants, foundation support, and Clark Fork Coalition members. The report was divided into two sections: (I) the science and what it means, and (II) actions and policies to shape the future. In Section I, global climate change models were downscaled to the local level to predict the ways in which climate change would likely affect temperature, precipitation, stream flows, glaciers, forests, fish, and wildlife in the Clark Fork basin. Section II suggests how Clark Fork’s citizens, businesses, and officials can respond to the projected impacts by addressing population growth, water use and efficiency, restoration, and recreation activities.

Climate change is already having an impact in the Clark Fork basin, thus the Clark Fork Coalition tried to emphasize implementation of proactive and positive strategies for people and ecosystems to adapt to climate change impacts. For example, the report suggests adaptation strategies such as minimizing urban sprawl; building fewer homes in fire-prone areas; allowing streams to utilize more floodplain area; boosting water conservation measures for homes, businesses, ranches and farms; and improving water delivery systems such as canals and ditches to increase water efficiency.

Finally, the Clark Fork watershed is becoming a model of a successful ‘restoration economy’. Over $600 million of Superfund cleanup and restoration dollars have been invested into the upper Clark Fork. These funds will allow the region to develop innovative and unique landscape-level approaches to adaptation and conservation. 

Outcomes and Conclusions

Low Flows Hot Trout: Climate Change in the Clark Fork Watershed had a great reception. The Clark Fork Coalition conducted extensive outreach surrounding its release. The report was introduced at a press luncheon in downtown Missoula that was attended by over 250 individuals, including conservation partners, local government leaders, interested citizens, and the press. Shortly following this inaugural luncheon, the Coalition hosted a “Headwaters Summit” conference at the University of Montana, bringing together water and land conservation partners from across the Pacific Northwest to discuss the impacts of climate change on their region. Since the conference, they have continued to roll out their report at the local, regional, and national level. Locally, they presented the report to business groups, realtors, conservation groups, students, and Kiwanis groups. Regionally, they showcased the report at the Headwaters Summit, to state conservation partners, and to state legislators. They have also presented the report twice at River Network trainings and national conferences in 2010. These presentations have served to jumpstart initiatives by other watershed groups dealing with the impacts of climate change. For example, the Utah Rivers Council used the report as an impetus to develop adaptation strategies and write a similar report for different Utah watersheds.

In addition, the Clark Fork Coalition is working on ways to increase the effectiveness of their outreach as well as making sure their local story is told to a wider audience. For example, they have created a website for the report, which is intended as a central resource for local and state policy makers and community leaders as they work toward developing adaptation strategies. The Clark Fork Coalition continues to conduct outreach and promote strategies based on findings in Low Flows, Hot Trout. They will give two presentations in 2011, one to the 2011 River Rally in Charleston, SC, and one to the Colorado Watershed Assembly at their 2011 conference in Vail, CO. The Coalition is also involved in the ClimateWise process as a convening partner, which will offer data regarding the impacts of climate change on ecological and economic sectors in Missoula County. The Coalition is tasked with bringing stakeholders together, hosting a two-day workshop, and disseminating a report and recommendations based on the findings throughout the process.

Meanwhile, on the policy end, they are working to accomplish the following: using legislative, administrative, and legal levers to fix the “exempt well rule” in Montana, which encourages subdivisions to use multiple individual wells without oversight of impacts on streams, groundwater, land sprawl, or other water users; revising and funding the Montana Aquatic Invasive Species Act; protecting Montana’s instream flow laws; and engaging citizens in the pending sale of Missoula’s private water utility, Mountain Water Company, to The Carlyle Group, a $98 billion global investment firm.

Other action items and outreach measures include: galvanizing community support and buy-in for buffering streams from development and climate change by identifying and presenting Stream Care Home Awards and leading an accredited “Living Near Streams” course for real estate professionals and property owners; demonstrating 'restoration for resilience', which helps buffer aquatic systems from climate change impacts by designing and facilitating stream and riparian projects on public and private land; facilitating “Watershed Restoration Certificates” to offset water footprints and develop tools exploring the links between energy production and water use; promoting the City’s Green Blocks program, which offers free energy and water audits to qualified homeowners; assisting in writing the City’s Climate Action Plan; advocating for restoring and maintaining ecological values at the 3,400-acre Smurfit-Stone site, a former industrial zone; recommending best steps for decreasing energy costs at the wastewater treatment plant; and implementing innovative market-based water transactions that increase flows in dewatered streams and rivers in the basin—including designing pressurized pipeline watering systems for landowners to reduce energy costs as well as greenhouse gas emissions.  


Information collected through interviews and publications. Last updated July 2011.


Kershner, J. (2011). Low Flows and Hot Trout: Dealing with the Effects of Climate Change in the Clark Fork Watershed [Case study on a project of the Clark Fork Coalition]. Product of EcoAdapt's State of Adaptation Program. Retrieved from CAKE: http://www.cakex.org/case-studies/low-flows-and-hot-trout-dealing-effec… (Last updated July 2011)

Project Contact(s)

Position: Communications

Founded in 1985, the Clark Fork Coalition is dedicated to protecting and restoring the Clark Fork River basin, a 22,000-square-mile area draining western Montana and northern Idaho. We have a 25-year-long record of substantial achievements improving the health of the watershed. 

Side by side with citizens, scientists, landowners, business leaders, and public officials, we have spearheaded initiatives that have delivered important gains, including:


Scale of Project
Regional / Subnational
Sector Addressed
Conservation / Restoration
Land Use Planning
Tourism / Recreation
Water Resources
Target Climate Changes and Impacts
Habitat extent
Water quality
Water supply
Water temperature
Climate Type
3-5 years
Type of Adaptation Action/Strategy
Natural Resource Management / Conservation
Incorporate future conditions into natural resources planning and policies
Enhance migration corridors and other connectivity measures
Create new refugia / Increase size and amount of protected areas
Capacity Building
Increase / Improve public awareness, education, and outreach efforts
Create stakeholder engagement processes to develop and implement adaptation strategies
Infrastructure, Planning, and Development
Community Planning (developing climate-smart communities)
Governance and Policy
Create new or enhance existing policies or regulations
Sociopolitical Setting
Effort Stage