Colorado’s stream ecosystems are having to do more with less. Changing conditions brought on by climate change and drought have led to diminished streamflow and earlier peaks in our hydrograph. At the same time, these hardworking rivers continue to support our communities by providing water for our growing municipalities and food production. Providing for these needs can leave our streams high and dry later in the season, stressing our fisheries and river-based recreation economies.
Reservoirs are constructed to address shortages by adding storage to our stream systems. They are a tool used to hold back supplies to provide for our human needs at a later date and can be operated to address issues with the timing of water supplies. Negative impacts from reservoirs can include altering natural flow regimes, impacting water quality, and changing how sediment travels through a system (leading to potential erosion). However, once built, reservoirs can also be used to provide for ecosystem needs. A lesser-known benefit from reservoirs is the crucial and often underappreciated role in supporting the health of our river ecosystems through the strategic release of water for environmental uses.
Fish require sufficient depth of water for feeding, to move throughout their habitat, and for reproduction. Planned releases from reservoirs ensure that these basic habitat needs are met by assuring that streams do not become too shallow, hot, or stagnant. Essentially, fish need water—and reservoir releases can provide for that need during times of shortage.
Water released for environmental flows during dry periods provides a broad range of benefits to other users as it travels downstream. It can support recreational economies, provide relief for municipal dischargers benefiting from cooler temperatures, and is eventually diverted downstream for other uses (typically agricultural).
I joined Colorado Water Trust’s board because I believe in the potential for better outcomes for our streams and water users through collaborative water sharing supported by Colorado’s prior appropriation system. Our reservoir projects do just this—they add water to maxed out stream systems when they need it most. While these environmental releases are protected through vulnerable reaches, they provide a broad range of benefits along the way and eventually are diverted to support downstream uses.
To date, Colorado Water Trust has completed six reservoir release projects throughout Colorado. We’ve collaborated on the Terrace Reservoir project, permanently restoring flows to the Alamosa River through rights donated to the State’s Instream Flow Program. Colorado Water Trust leads a collaborative group that funds releases from the Stagecoach Reservoir on the Yampa when flows get too low. These releases support the ecological integrity of the Yampa River, lowering stream temperatures and supporting fisheries when they are most maxed. But it also supports tubing through the Town of Steamboat, the recreational fly-fishing economy, and helps the Steamboat municipality meet discharge requirements.
These projects often require diverse stakeholders to come together to work out the management frameworks that will result in co-benefits. As projects come online, release schedules may need to be tweaked and adapted to best meet the needs of evolving systems. However, while collaborative work can be challenging, it’s often the most rewarding and results in the best outcomes. In my opinion, this is what makes Colorado Water Trust’s reservoir projects the epitome of a win-win.
We’re getting excited to announce our newest reservoir project in Boulder County. Stay tuned for big news!
[Editor’s Note September 3rd, 2024 = Here’s a link to the announcement for our newest project.]
Julie Nania
President, Colorado Water Trust Board of Directors
Executive Director, Cold Harbour Institute