Photo Credit: Riverhugger

By the Colorado Water Trust staff

In October 2016, The Durango Herald carried a modest story sporting the headline, “Trout Discovered in Creek Long Devoid of Fish.”  In the southwest corner of Colorado, where abandoned mines and contaminated streams have long been a part of the otherwise magnificent mountain landscape, this is encouraging news—especially for a community that, just two years ago, saw the Animas run yellow.

The San Antonio Mine complex, north of Silverton, Colorado, has been a fixture on the flanks of Red Mountain Pass for over 100 years. While most active mining ceased in the 1940s, the spoil piles and orange drainage from the Kohler Tunnel remained, contaminating streams with high concentrations of copper, lead, cadmium and zinc, and eliminating the fishery resource in Mineral Creek.

In the late 1990s and early 2000s, several entities joined together with the hopes of improving water quality and restoring the natural function of the watershed. The Animas River Stakeholders Group, whose mission is to improve water quality and aquatic habitat in the Animas Watershed, determined that drainage from the Kohler Tunnel contributed the largest amounts of metals to the upper Animas Watershed. As a result, the stakeholders group designated the tunnel drainage as its highest priority for remediation.

Photo Credit: USGS

Hydrogeological studies and other research conducted by the stakeholders group identified the Carbon Lake Ditch as the likely source of water seeping into the mine and the Kohler Tunnel, impacting water quality. The 50-year-old irrigation ditch diverts from the upper Mineral Creek Basin and winds its way across the mine complex to deliver water to the other side of Red Mountain Pass. Winter ice buildup in the ditch and heavy summer rains caused occasional breaches, resulting in erosion and surges of mine drainage from the tunnel. The obvious solution was to eliminate the source of water infiltrating the mine, so the stakeholders group targeted their efforts on the ditch.

With a grant from the U.S. Environmental Protection Agency, the Animas River Stakeholders Group purchased the entire 15 cubic feet per second (cfs) Carbon Lake Ditch water right from the owners who were willing to part with their water right in favor of reliable, local water supplies. The stakeholders group removed the physical structures from the streams, completed ecological restoration of the ditch and plugged the Kohler Tunnel to prevent future drainage into the stream.

Discontinuing diversions and removing the headgate did not guarantee that the restored flows would stay in Mineral Creek to benefit the environment—legally, that water would be free for other uses under Colorado’s prior appropriation system. The next challenge was to find a way to protect those restored flows. The Animas River Stakeholders Group and project partner the San Juan Resources Conservation and Development Council reached out to the Southwestern Water Conservation District and a local law firm where the attorney consulted was a former Colorado Water Conservation Board (CWCB) member with a wealth of knowledge about Colorado’s Instream Flow Program.

Colorado’s Instream Flow (ISF) Program was the linchpin in the stakeholders group’s success. In the early 1970s, the Colorado Legislature pioneered protections for the water-dependent natural environment by creating the ISF Program.  An instream flow is a statutorily recognized type of water right that protects a natural stream from an upstream point to a downstream point. These water rights are administered like any other water right in the state, with a priority date confirmed by water court decree. At the time, the program provided the CWCB with the exclusive authority to appropriate or acquire water for instream flows to preserve the natural environment.

The CWCB can appropriate new junior instream flow water rights or acquire senior water from willing water rights owners for instream flow use. Under this acquisition authority, once an agreement is reached with the willing owner, the CWCB changes the water right through the water court change process to instream flow use. The water right is then legally protectable in the river with its original priority date. It is CWCB’s acquisition authority that the stakeholders group sought to secure instream flow protections for the newly-purchased Carbon Lake Ditch water right.

In March 2001, the Animas River Stakeholders Group and the San Juan Resource Conservation and Development Council presented the CWCB with an offer to donate the Carbon Lake Ditch water right to the Instream Flow Program to protect restored flows in Mineral Creek and two tributaries. However, in the course of conducting routine investigations, CWCB staff identified a significant program limitation. The original statutes passed in 1973 placed sideboards on the CWCB’s authority, limiting water appropriations and acquisitions to the minimum amounts required to preserve the natural environment. In the case of Mineral Creek, the amounts required to preserve the environment were determined to be between 2.5 and 6.6 cfs.  Yet, the Carbon Lake Ditch water right was decreed for 15 cfs, and under the existing law, there was no way to protect all of the restored water with an instream flow right.

As highlighted in CFWE’s spring 2004 Headwaters Magazine issue, “Changing Times, Changing Uses”, societal values change. In 2002, the legislature passed Senate Bill 156, allowing CWCB to acquire water rights to preserve and to improve the natural environment. This amendment, the first significant change to the Instream Flow Program in more than 30 years, broadened the CWCB’s authority and created statewide opportunities to restore streamflow to dewatered streams and to improve existing environmental conditions. After the bill was signed into law, the CWCB clarified the water right donation and changed the full 15 cfs of the Carbon Lake Ditch water right for instream flow use to preserve and improve the natural environment. Roughly 15 years after the legislative change and the CWCB’s acquisition of the Carbon Lake Ditch water right for instream flow use, we see tangible results.

“This is the first time in recorded history of a report of fish existing in the headwaters of Mineral Creek,” said Bill Simon, retired coordinator for the stakeholders group, in the 2016 Durango Herald article. “We are a bit surprised by the great results so soon after remediation.”

Mineral Creek     Photo Credit: Larry Lamsa

The presence of a resident brook trout population with diverse age ranges is indicative of the dramatic improvement in water quality within the reach where flows were restored and are now protected by the CWCB’s instream flow right. The Durango Herald reports an amazing 70 percent reduction in zinc and copper, and a 50 percent reduction in cadmium in Mineral Creek since completion of remediation and flow restoration.

“We knew that water quality in the upper part of Mineral Creek had dramatically improved,” said Peter Butler, Animas River Stakeholders Group coordinator, “but we didn’t expect it to support trout.”

The fantastic success story for Mineral Creek and the stakeholders group is a testament to the possibilities when local communities, state agencies and the legislature work together to solve problems. With CWCB’s ability to acquire water to improve the natural environment, this is a success story for the entire state of Colorado. The benefits achieved in Mineral Creek can, over time, be realized on many other streams, too.

Colorado’s ISF Program, now in its 45^th year, operates statewide and the acquisition tool is available to any water right owner interested in donating, leasing or selling all, or a portion of, their water to preserve or improve the natural environment. The Colorado Water Trust, a nonprofit created in 2001 to restore flows to streams and rivers in need, works closely with the CWCB and can help facilitate temporary and permanent water transactions throughout the state.

Learn more about how to use water to benefit the natural environment by visiting the Colorado Water Trust and Colorado’s Instream Flow Program websites.

The Colorado Water Trust is a non-profit organization created in 2001 to restore flows to Colorado’s rivers in need.  The Water Trust uses voluntary, market-based tools to develop projects with water right owners to help keep Colorado’s rivers flowing. The Water Trust works closely with the Colorado Water Conservation Board and the state’s Instream Flow Program to ensure flows are protected. For more information about the Water Trust or completed projects, please visit www.coloradowatertrust.org.