Project Active
2014 – Present

Alamosa River – Terrace Reservoir
Through 2022, the Terrace Reservoir Project has restored over
billion gallons
acre-feet
How Did This Project Come to Us?:
The Alamosa River Watershed Restoration Master Plan and Environmental Assessment, created to support the river and the watershed after it had been affected by low flows and contamination, brought on Colorado Water Trust as a technical consultant for water rights and instream flow information in 2008.
Tools Used:
Permanent Water Right Acquisition (Alamosa Riverkeeper used mitigation funding to purchase water rights diverted from the Alamosa River, and donated the water for permanent enrollment in the State’s Instream Flow Program. Every year, the water rights are stored in Terrace Reservoir and released to keep the river flowing in November, where it was historically dry prior to the project’s implementation.)
Project Partners:
Alamosa RIVERKEEPER, Colorado Water Conservation Board, Terrace Irrigation Company, Colorado Parks and Wildlife, URS Corp. (Project Consultant), Porzak Browning & Bushong LLP (Legal Assistance)
Project Years:
This project has restored flows to the river since 2015.
Project Story:
On November 5, 2015, the Division 3 water court issued final decrees to permanently bolster streamflow in the Alamosa River. These are the first water rights in the Alamosa River decreed for use by the Colorado Water Conservation Board (CWCB) for restoring streamflow. The water court’s official approvals for the new use of these water rights are the final steps in a multi-year process, spearheaded by Alamosa RIVERKEEPER® and the CWCB.

The Alamosa River, looking downstream
In addition to extending the season of flows in the Alamosa River, releases will supplement a 16-mile stretch of the river during periods of low flow to support the fishery and aquatic environment, improve riparian health, keep the streambed wet to limit loss of irrigation water, and recharge aquifers. The Colorado Water Trust has been associated with this project since 2008 as a technical consultant to Alamosa RIVERKEEPER® for water rights and instream flow information as they work to improve the water quality and the ecological functionality of the Alamosa River.
The Alamosa River and its watershed were contaminated by cyanide and toxic metals due to irresponsible mining practices at the Summitville mine, which eventually lead to a Comprehensive Environmental Response, Compensation and Liability Act, or Superfund, designation in 1992. Alamosa RIVERKEEPER® developed the Alamosa River Watershed Restoration Master Plan and Environmental Assessment (Master Plan) with comprehensive, broad objectives to restore the Alamosa River watershed. As part of this Master Plan, they purchased water rights in their watershed (2.5 cubic feet per second (cfs) of water from the Gabino Gallegos Ditch and 0.5 cfs in the Valdez Ditch) and then donated these water rights to the CWCB to enroll them in the state’s Instream Flow Program.
- Photo Credit: Colorado Water Trust Staff
Alamosa Riverkeeper works with Trust
The Conejos County Citizen
CAPULIN– Colorado Water Trust has been around since 2001, and we have a lot to show for it, with over 11.5 billion gallons of water...
It takes a village to restore flows
Colorado Water Trust has been around since 2001, and we have a lot to show for it, with over 11.5 billion gallons of water restored to 444 miles of rivers...
Alamosa River receives streamflow restoration
CAPULIN – Water running down the Alamosa River finally will be officially protected as instream flow. On November 5, the Division 3 Water Court issued a final decree, formally confirming...
Absolute Decree of FIRST Instream Flow in Alamosa River
On November 5, 2015, the Division 3 water court issued final decrees to permanently bolster streamflows in the Alamosa River. These official decisions by the water court are the final...
Rebirth: Alamosa River, left for dead, is coming back
Pueblo Chieftain, June 11, 2015
Matt Hildner
CAPULIN — A river once left for dead by mine-polluted runoff in the southwestern corner of the San Luis Valley is coming...
Historic First Instream Flow Release on the Alamosa River
November 1, 2014, was an historic day! Terrace Reservoir began releasing the 162 acre-feet of water that they had stored for Alamosa Riverkeeper (ARK) and Colorado Water Conservation Board (CWCB)...
Connecting the Drops: Rethinking Reservoirs
Colorado Foundation for Water Education and 88.5 KGNU Community Radio have been teaming up to share water information over the airwaves through their series, Connecting the Drops. In July’s episode,...
Valdez Ditch water right offered for instream flow use
In 2012, Alamosa Riverkeepers acquired an additional 0.5 cfs water right in the Valdez ditch and offered it to the CWCB for use in the Instream Flow Program. Alamosa Riverkeepers...
Water 2012: Summitville anniversary is nothing to celebrate
VALLEY — The year 2012 marks the 20th anniversary of the Summitville mining disaster which permanently altered the Alamosa River watershed that covers 148 square miles.
In 1992, U.S. Environmental...
Funding Construction at Terrace Reservoir
Alamosa Riverkeepers are working in collaboration with the Terrace Irrigation Company to replace the existing Terrace Reservoir spillway. Replacing and upgrading the spillway will improve the reservoir by increasing...
Gabino Gallegos Ditch water right offered for instream flow use
As part their work to restore the Alamosa River and its watershed, Alamosa Riverkeepers acquired and offered to the CWCB 2.5 cfs of water from the Gabino Gallegos Ditch to...