Project Active

2016 – Present

Little Cimarron River – McKinley Ditch

A groundbreaking split-season water sharing agreement between agriculture and the environment.


Through 2020, the McKinley Ditch Project has restored over

million gallons


of water to the Little Cimarron River.

This split-season water use agreement, once operational, will be the first of its kind in the western United States.

When people think of healthy rivers, they correctly think of flowing water and lush riparian areas, not a dry river with puddles interspersed between rocks. Unfortunately, this is often the case along a three-mile segment of the Little Cimarron River in western Colorado. But the McKinley Ditch project provides a pioneering opportunity that when implemented, will greatly improve the health of the river while maintaining production on agricultural lands.

Little Cimarron River streambed

Little Cimarron River streambed

In January 2014, Colorado Water Trust purchased a portion (5.8 cfs) of the McKinley Ditch to help restore late summer flows to the Little Cimarron. Project goals include keeping agricultural lands irrigated, keeping water flowing through a three mile segment of what is often dry stream, and reconnecting habitat. Colorado Water Trust and Colorado Water Conservation Board filed for a change of water right in water court in December 2014 to utilize their McKinley Ditch water for instream flow use in late summer and early fall, with the intent of keeping the water on the land for irrigation during spring and early summer. A final decree was signed on October 1st, 2018.

While working through the water court process, the Water Trust was exploring ideas for how to use their McKinley Ditch water until the decree is signed. As part of that effort, in July of 2016, the Water Trust received approval from the Upper Colorado River Commission to enroll the Water Rights in the 2016 System Conservation Pilot Program (“SCPP”). Enrolling the water rights in the SCPP allowed for the Water Trust’s McKinley Ditch to irrigate approximately 195 acres of pasture grass from April through July 6th.

McKinley Ditch headgate

McKinley Ditch headgate

On July 7th, 2016, the water was removed from irrigation for the remainder of the irrigation season (the irrigation season ends annually on Oct. 31). The use of the McKinley Ditch shares in 2016 was beneficial both to the SCPP and the Water Trust, as operations mimicked future split season use and protected the water rights, before the final decree had been signed by the court. Water conserved by the Pilot Program helped to improve habitat conditions and provided benefit the Little Cimarron and downstream reaches of streams. We are hopeful the System Conservation Pilot Program results will help to identify reliable tools to address water shortages, and will lead to a more secure future for Colorado’s rivers.

The kind of creative collaboration required to make this project a success is essential to the future of Colorado’s rivers. The McKinley Ditch Project utilizes a water-sharing agreement that falls into a category of water transfers what Colorado’s Water Plan labels “Alternative Transfer Methods,” or “ATMs.” The use of ATMs, such as the split-season agreement used in the McKinley Ditch Project, offer new solutions for Colorado’s water future that alleviate the need for “buy-and-dry” transfers (which take agricultural lands out of production permanently).


  • Photo Credits: Colorado Water Trust Staff
  • Project Partners: Colorado Water Conservation Board, Western Rivers Conservancy, Colorado Parks and Wildlife, Bonneville Environmental Foundation, McKinley Ditch Shareholders
  • Project Consultants: Bishop-Brogden Associates, Inc., Tessara Water, LLC, One Fish Engineering, LLC and Flywater, Inc.

Use the flow dashboard below to learn about the operations of the McKinley Ditch project, and just how much water has been restored to Little Cimarron River over the project’s lifetime. Just click or hover over the graphs below to learn more!

If you have trouble seeing the graphs below, click here