EC -
Alamosa River Watershed
Mountain-Prairie Region
Graphic button showing the 8 state mountain prairie region

Alamosa River Watershed - Summitville


Jump to a section: Key features in the watershed | Public documents, links and contacts | « Back to Contaminants

Wightman Fork, Tributary to the Alamosa River. Summitville is in the background. Credit: USFWS.

Wightman Fork, Tributary to the Alamosa River. Summitville is in the background. Credit: USFWS.

Background: The Alamosa River watershed comprises 148 square miles in the San Luis Valley of south-central Colorado.  The mainstem of the Alamosa River is 51 miles long, extending from near the Continental Divide to east of La Jara. Elevations vary from over 13,000 feet to about 7,600 feet where the river ends at the Lowland and Head Overflow ditch headgates just east of Highway 285.  Primary tributaries to the Alamosa River include Treasure Creek, Iron Creek, Alum Creek, Bitter Creek and Wightman Fork. Several smaller tributaries also drain into the Alamosa River.  Some of Colorado’s oldest communities are located in the Alamosa River watershed, including La Jara and Capulin.  The economy in the watershed is supported primarily by agricultural and recreation-oriented tourism.

Key features in the watershed »

« Back to the top

-  Summitville Mine, a gold mine that operated most recently from 1986 to 1992 using open pit and cyanide leach methods but which is now a Superfund site;
-  Terrace Reservoir, a storage impoundment for irrigation water;
-  Extensive irrigated agriculture in the lower watershed;
-  Extensive forested areas in the upper watershed. 

The Alamosa River watershed has been significantly impacted by human activity. Primary sources of impact include the following:

-  Straightening of parts of the river downstream of Terrace Reservoir to improve channel capacity and sediment transport has potentially injured the natural function of riparian corridors; affected habitat, vegetation and groundwater levels; and reduced the effectiveness of irrigation diversions.
-  Contamination of surface and ground water by runoff from the Summitville mine site and other mining activities has potentially injured aquatic habitat in stream reaches below the mine area and impacted downstream water users.
-  Over-appropriation of surface flows has dried up portions of the stream channel during parts of the year.
-  Over-use of riparian areas for agriculture and ranching has adversely impacted wildlife and aquatic habitat.
-  Reduced flows and poor water quality have impacted the recreation value of the watershed resources. 

The State of Colorado and the United States recovered $5,000,000 in Natural Resource Damages to use to restore, replace, or acquire the equivalent of the natural resources potentially injured by the hazardous substances released by the Summitville Mine. There are three federal natural resource trustees and three State natural resource trustees (Trustees) who guided the Master Plan process and will also guide implementation:

 -  United States Department of the Interior's Fish and Wildlife Service
 -  United States Department of the Interior's Bureau of Land Management
 -  United States Department of the Agriculture's Forest Service
 -  Colorado Attorney General
 -  Executive Director of the Colorado Department of Public Health and the Environment
 -  Director of the Colorado Department of Natural Resources.

Public documents, links and contacts »

« Back to the top

Public Documents 
  Final Alamosa River Watershed Restoration Master Plan  
      The final plan describes the Alamosa River environment and the impacts to watershed resources and land uses, and briefly describes proposed restoration projects.   It addresses watershed restoration needs, including those resulting from potential injuries to natural resources due to releases of hazardous substances from the Summitville mine site.   The final plan is pursuant to the federal Natural Resource Damage Assessment and Restoration (NRDAR) regulations in CFR 43 Part 11.

Master Plan -  Alamosa River Watershed Restoration Master Plan 

Executive Summary 
      Front Cover (pdf, 5 MB)
      Pages 1 - 9   (pdf, 6.5 MB)
      Pages 10 - 14 (pdf, 2.5 MB)
      Pages 15 - 20 (pdf, 6 MB)
      Back Cover (pdf, 1 MB)

 Master Plan 
      Cover and Table of Contents (pdf,5.4 MB) 
      Report Tabs (pdf, 2.6 MB)
      Section 1 (pdf, 3.2 MB) 
      Section 2.1, 2.2 and 2.3  (pdf, 6.1 MB) 
      Section 2.4 (pdf, 5.1 MB) 
      Sections 2.5 to 2.13 (pdf, 5.8 MB) 
      Section 3  (pdf, 5.5 MB) 
      Sections 4 to 6  (pdf, 1.8 MB) 

      Appendix A (pdf, 62 KB) 
      Appendix B (pdf, 115 KB) 
      Appendix C (pdf, 34 KB) 
      Appendix D (pdf, 71 KB) 
      Appendix E - Title Page (pdf, 12 KB) 
      Appendix E - Segments 1, 2, and 3 (pdf, 792 KB) 
      Appendix E - Segment 4 (pdf, 739 KB) 
      Appendix E - Segment 5 (pdf, 470 KB) 
      Appendix E - Segment 6 (pdf, 523 KB) 
      Appendix E - Segment 7 (pdf, 651 KB) 
      Appendix E - Segment 8 (pdf, 787 KB) 
      Appendix E - Segment 9 (pdf, 714 KB) 
      Appendix E - Segment 10 (pdf, 512 KB) 
      Appendix E - Segment 11 (pdf, 737 KB) 
      Appendix E - Segment 12 (pdf, 657 KB) 
      Appendix E - Segment T1 (pdf, 673 KB) 
      Appendix E - Segment W1 (pdf, 513 KB) 
      Appendix E - Segment W2 (pdf, 457 KB) 
      Appendix E - Segment W3 (pdf, 565 KB) 
      Appendix E - Segment W4 (pdf, 495 KB) 
      Appendix F - Title Page (pdf, 12 KB) 
      Appendix F - Segment 1 (pdf, 1.4 MB) 
      Appendix F - Segment 2 (pdf, 2.1 MB) 
      Appendix F - Segment 3 (pdf, 2.2 MB) 
      Appendix F - Segment 4 (pdf, 2 MB) 
      Appendix F - Segment 5 (pdf, 1 MB) 
      Appendix F - Segment 6 (pdf, 0.5 MB) 
      Appendix F - Segment 7 (pdf, 1.5 MB) 
      Appendix F - Segment 8 (pdf, 0.6 MB) 
      Appendix F - Segment 9 (pdf, 1.6 MB) 
      Appendix F - Segment 10 Wightman Fork to Jasper Creek (pdf, 1.7 MB) 
      Appendix F - Segment 11 Iron Creek to Wightman Fork (pdf, 1 MB) 
      Appendix F - Segment 12 Treasure Creek to Iron Creek (pdf, 2.1 MB) 
      Appendix F - Segment T1- Treasure Creek Watershed  (pdf, 2.2 MB) 
      Appendix F - Segments W1, W2, W3, and W4 (pdf, 1.9 MB) 
      Appendix G to J  (pdf, 1 MB)

Links to more information 
  U.S. EPA - 

  Colorado State Department of Health and Environment-  

  U.S. Geological Service-

  If you have any questions or comments related to the Summitville NRDA, contact us via email or telephone:

Laura ArchuletaContaminants Specialist, U.S. Fish and Wildlife Service, phone 719-655-6121, fax 719-665-2502.    


The mission of the U.S. Fish and Wildlife Service is working with Others to conserve, protect, and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American People.
Last modified: June 30, 2014
All Images Credit to and Courtesy of the U.S. Fish and Wildlife Service Unless Specified Otherwise.
flickr youtube