Help Defend the Upper Colorado

Soon, up to 80% of the Upper Colorado could be diverted to the Front Range. Take action today!


The Upper Colorado River is one of the west’s most iconic - and most at-risk - rivers. Today, over 60% of the Colorado River's native flows are permanently removed at its headwaters and diverted to cities and suburbs across the Front Range, leaving behind a trickle for fish and wildlife, recreation, agriculture, and the local communities that depend on the Colorado River and its tributaries.

And now, despite severe impacts to fish and recreation and public outcry, water providers want to take more through the Windy Gap Firming Project and Moffat Tunnel expansion, putting the Upper Colorado River and key tributaries like the Fraser River at risk for a system-wide collapse.


The Upper Colorado River and its major tributaries like the Fraser River can be saved for future generations if and only if water providers commit to doing the right thing - developing water projects in a way that keeps the river flowing and cool. The following must be included in each project:

  • Intensive monitoring of fish populations, water temperature, water quality, and flows on creeks and tributaries that supply water to both projects to determine if and when rivers and streams decline.
  • A commitment to change when and how much water is diverted if the river shows signs of collapse. Warm water temperatures, water quality problems, and fish population or macroinvertebrate declines are all conditions that warrant changes in the amount and timing of water diversions.
  • Funding set aside to restore and repair the river. In cases where the river becomes too shallow to support fish and/or meet the state's water quality standards, funds should be invested in an Endowment to cover the costs of necessary restoration. This could include deepening the channel or adding willows and other plants to create shade and keep water temperatures within an acceptable range for fish.

Take Action

If you care about the Colorado River, please consider taking the following actions to keep the river and its fish and wildlife alive:

About the Moffat + Windy Gap Firming Project

The following is intended to provide a brief overview of both water projects that threaten the healthy of the Upper Colorado River and its tributaries like the Fraser River:

  • Windy Gap Firming Project. Water provider Northern Colorado Water Conservancy District has proposed to increase the amount of water they currently pump from Windy Gap Reservoir to the Front Range from 50% to 80% of the river's native flows and storing it across the continental divide in a new reservoir (Chimney Hallow). The river below Windy Gap is already in serious decline with documented losses in trout, stoneflies, sculpin, and water quality. Colorado TU is calling for a comprehensive mitigation package including protections for water temperature and flushing flows, a “bypass” to help reconnect the Colorado River where Windy Gap’s dam has severed it, and funding for river restoration.
  • Moffat Expansion Project. Water provider Denver Water has proposed to significantly increase its diversions from the Fraser and Williams Fork Rivers to provide additional supply its Denver-metro customer base. While Denver’s recent west slope agreement promises some help in addressing existing river problems, it does not address the impacts of the new project on fish and river health. TU is advocating for a responsible mitigation package including protections for flushing flows and stream temperature, as well as funding for river restoration as an “insurance policy” to ensure healthy flows and fish continue to exists within the Colorado, the Fraser, and key tributaries like Ranch Creek.

Questions? Contact Erica Stock, Colorado TU Outreach Director.