- Skip to Primary Navigation
      - Skip to Main Content
      - Skip to Footer

          -   
          -   
          -   
          -   
          -   
          -   
          -   
          -   

        -  Water & Power            - Dams
          - Powerplants
          - Projects
          - Agrimet/Hydromet
          - Water Operations 
        -  Resources & Research            - Programs
          - Technical Service Center
          - Research & Development
          - Reclamation Manual
          - Environmental Resources/Reports
          - Library 
        -  About Us            - Mission/Vision
          - Fact Sheet
          - Commissioner
          - Addresses/Contacts
          - Organizational Chart
          - Leadership Bios
          - Employment
          - Contact 
        -  Recreation & Public Use            - Find Recreation
          - Recreation.gov
          - Public Use 
        -  News & Multimedia            - News Releases
          - News Stories
          - Speeches
          - Congressional Testimony
          - Fact Sheets
          - Photos
          - Multimedia
          - Social Media 

# Interior Region 7 • Upper Colorado Basin

Encompassing all or parts of Arizona, Colorado, Idaho, Nevada, New Mexico, Texas, Utah and Wyoming

              - Reclamation
              - Upper Colorado Region
              - Glen Canyon Dam Adaptive Management Program

Upper Colorado Basin              - Upper Colorado News
              - About Us
              - Area Offices
              - Programs & Activities                  - Animas-La Plata Project
                - Colorado River Basin Salinity Control Program
                Paradox Valley Unit

                - Colorado River Storage Project
                Aspinall Unit
Flaming Gorge Unit
Glen Canyon Unit
Navajo Unit

                - Cultural Resources Program
                - Glen Canyon Dam Adaptive Management Program
                Adaptive Management Work Group
Technical Work Group
Long-Term Experimental and Management Plan

                - Gunnison Basin Selenium Management Program
                - Navajo-Gallup Water Supply Project
                - New Mexico Pueblos Irrigation Infrastructure Improvement Project
                - Pojoaque Basin Regional Water System
                - Sedimentation at Paonia Reservoir
                - System Conservation and Efficiency Program
                - Water Conservation Field Services Program
                - Water Project Automation
              - Document Library
              - Environmental Documents
              - Water Operations
              - Contact Us

# Glen Canyon Dam 			Adaptive Management Program

The Glen Canyon Dam Adaptive Management Program was developed to provide an organization and process for cooperative integration of dam operations, downstream resource protection and management, and monitoring and research information, as well as to improve the values for which the Glen Canyon National Recreation Area and Grand Canyon National Park were established.

Adaptive management is a dynamic process where people of many talents and disciplines come together to make the right decision in the best interests of the resources.

Quick Nav                  - Current Focus
                  - Project Background
                  - Program Background
                  - Contact Us
                  - Related Documents
                  - Stay connected

## Current Focus

### Glen Canyon Dam/Smallmouth Bass Future Flow Options and High-Flow Experimental Protocol

The Bureau of Reclamation has released the draft Supplemental Environmental Impact Statement for the Glen Canyon Dam Long-Term Experimental and Management Plan. The supplement is to the December 2016 Record of Decision for the Glen Canyon Dam Long-Term Experimental and Management Plan Final Environmental Impact Statement, referred to as LTEMPROD.

#### Purpose and Need

The purpose of the LTEMPSEIS is for Reclamation to analyze additional flow options at Glen Canyon Dam in response to nonnative i smallmouth bass and other warmwater nonnatives recently detected directly below the dam. The need is to disrupt the establishment of smallmouth bass below the Glen Canyon Dam by limiting additional recruitment, which could threaten populations of threatened humpback below the dam.

The LTEMPSEIS also considers the high flow experiment (HFE) protocol by including the latest scientific information to improve Reclamation's ability to implement HFE releases as originally intended in the LTEMPFEIS. Specifically, Reclamation is considering adjusting sediment accounting periods and HFE implementation windows.

#### Alternatives

The draft SEIS considers six alternatives:
                  - No Action Alternative , required by the National Environmental Policy Act, describes the continued implementation of the  LTEMP  ROD , there would be no changes to operations at Glen Canyon Dam. Sediment accounting and HFE implementation will continue as described in the  LTEMP  ROD .
                  - Cool Mix Alternative , designed to disrupt smallmouth bass spawning, would involve strategic water releases from both penstocks and river outlet works to maintain a daily average water temperature below 15.5°C (60°F). This release quantity would vary throughout the year, influenced by monthly water volumes and temperature conditions.
                  - Cool Mix with Flow Spike Alternative , water would be released through the penstocks and river outlet works to maintain a daily average water temperature below 15.5°C (60°F) from below the dam to Lees Ferry or the Little Colorado River, with the objective of disrupting smallmouth bass spawning. In this alternative, up to three 36-hour flow spikes could be implemented if sufficient water is available. The flow spike is anticipated to disrupt spawning in margin habitats that may be warmer than the mainstream river. During a flow spike, as much water as possible (up to 45,000 cfs) would be released through the penstocks and river outlet works.
                  - Cold Shock Alternative , would include a release of water through the river outlet works that is designed to induce a short-duration cold shock, targeting temperatures of 13°C (55°F) either below at Lees Ferry or the Little Colorado River to disrupt smallmouth bass spawning and rearing.
                  - Cold Shock with Flow Spike Alternative , would include a release of water through the river outlet works that is designed to induce a short-duration cold shock, targeting temperatures of 13°C (55°F) either below at Lees Ferry or the Little Colorado River to disrupt smallmouth bass spawning and rearing. . In addition, up to three 36-hour flow spikes could be implemented if sufficient water is available. The flow spikes aim to disturb spawning in margin habitats, which are potentially warmer than the mainstream river. As much water as possible, up to 45,000 cfs, would be released through penstocks and river outlet works during flow spikes. This flow spike could be replaced by an HFE release if it maximizes benefits to sediment and is appropriately timed to impact smallmouth bass spawning.
                  - Non-Bypass Alternative , proposes a hydrograph centered on strategically employing substantial river stage changes to disrupt existing nests and spawning activities.  The hydrograph consists of a once weekly short-duration low flow release, with the goal of dewatering certain nests, immediately followed by a short-duration high flow release, with the goal of flushing any remaining nests.

Under all action alternatives, operations would continue pursuant to the continued implementation of existing agreements that control operations of Glen Canyon Dam.

In addition, in accordance with the LTEMPSEIS purpose and need, Reclamation would implement changes to the sediment accounting period and implementation windows.. These changes consist of adjusting the semiannual sediment accounting period to an annual period with the option for a spring and/or a fall HFE.

#### Public Involvement

The draft SEIS was published in the Federal Register on February 9, 2024, starting the 45-day public comment period.

Written comments on the draft SEIS should be submitted by March 25, 2024. Please send written comments pursuant to this notice to LTEMPSEIS@usbr.gov or by mail to Bureau of Reclamation, Attn: LTEMPSEIS Project Manager, 125 South State Street, Suite 800, Salt Lake City, UT 84138.

Reclamation held three virtual public meetings to provide information on the draft SEIS and to answer questions.

##### Meeting presentation **Link is to a PDF file

##### Friday, Feb. 16, 2024

##### Tuesday, Feb. 20, 2024

##### Thursday, Feb. 22, 2024

Before including your address, phone number, email address or other personal identifying information in any correspondence, you should be aware that your entire correspondence—including your personal identifying information—may be made publicly available at any time. While you may ask us in your correspondence to withhold your personal identifying information from public review, we cannot guarantee that we will be able to do so.

For further information, contact Kathleen Callister, Adaptive Management and Water Quality Division Manager, Bureau of Reclamation, at (801) 524–3867, or by email at LTEMPSEIS@usbr.gov.

##### Public comment letters

###### Tribes

                      - Colorado River Indian Tribes
                      - Pueblo of Zuni

###### Governments

                      - Arizona Electric Power
                      - Arizona Game and Fish Department
                      - Central Arizona Project
                      - City of Logan, Utah
                      - City of Manti, Utah
                      - City of Nephi, Utah
                      - City of Price, Utah
                      - City of Provo, Utah
                      - City of Salem, Utah
                      - City of Spanish Fork, Utah
                      - City of St George, Utah
                      - Electrical District Number Seven
                      - Heber Light and Power
                      - Maricopa Water District
                      - National Park Service
                      - Navajo Tribal Utility Authority
                      - Roosevelt Irrigation District
                      - Salt River Project
                      - Town of Levan, Utah
                      - Town of Oak City, Utah
                      - United States Environmental Protection Agency Region 9
                      - United States Fish and Wildlife Service
                      - Upper Colorado River Commission
                      - Utah Municipal Power Agency
                      - Washington City Power
                      - Western Area Power Administration
                      - Wyoming Municipal Power Agency

###### Organizations

                      - American Whitewater
                      - Arizona Public Power Associations
                      - BlueRibbon Coalition
                      - Center for Biological Diversity
                      - Colorado River Basin States Adaptive Management Work Group Representatives
                      - Colorado River Commission of Nevada
                      - Colorado River Energy Distributors Association
                      - Glen Canyon Dam Adaptive Management Work Group Recreational Fishing Representatives
                      - Grand Canyon River Guides
                      - Grand Canyon River Outfitters Association
                      - Grand Canyon Trust
                      - Grand Canyon Wildlands Council
                      - National Parks Conservation Association
                      - Upper Division States Adaptive Management Work Group Representatives
                      - Utah Associated Municipal Power Systems
                      - Wyoming, Nebraska, Utah, Colorado, Arizona, and New Mexico Representatives of Electric Cooperatives

#### Next Steps

A final supplemental EIS with Record of Decision, as appropriate, is anticipated to be available by early summer 2024.
                  - Modeling the Impacts of Glen Canyon Dam Operations on Colorado River Resources **Link is to a PDF file

----

**In-Depth**
                  - Glen Canyon Dam Long-Term Experimental and Management Plan Compliance and Conservation Measures Progress Reports
                  - Glen Canyon Dam Long-Term Experimental and Management Plan Environmental Impact Statement **
                  - Reports to Congress on Glen Canyon Dam Operations

### Related Projects & Facilities

                  - Colorado River Storage Project
                  - Glen Canyon Dam
                  - Glen Canyon Powerplant

### Related Links

                  - Glen Canyon Dam page
                  - Glen Canyon Dam on Recreation.gov **
                  - Grand Canyon Monitoring and Research Center Website **
                  - Glen Canyon Dam Adaptive Management Program WIKI Site **
                  - Proceedings of the Colorado River Basin Science and Resource Management Symposium **

## Project Background

### Glen Canyon Dam/Smallmouth Bass Future Flow Options and High-Flow Experimental Protocol

Lake Powell water levels remain at historically low levels, which has contributed to increased fish passage through Glen Canyon Dam and warmer water being released through the dam. Below the dam, these warmwater releases are creating ideal spawning conditions for smallmouth bass, a predatory invasive fish species that poses a threat to the federally protected humpback chub and other native fish.

To respond to the threat of smallmouth bass establishment below Glen Canyon Dam, a targeted draft Environmental Assessment **Link is to a PDF file was prepared that identified various flow options designed to disrupt smallmouth bass from spawning below the dam.

Based on the Comment Analysis Report **Link is to a PDF file and the nearly 7,000 comments received, Reclamation concluded that additional analysis was warranted. Consistent with the National Environmental Policy Act process, Reclamation transitioned this analysis to an Environmental Impact Statement process that supplements the December 2016 Record of Decision for the Glen Canyon Dam Long-Term Experimental and Management Plan Final Environmental Impact Statement.

This process was formally initiated through a Notice of Intent in the Federal Register ** on Oct. 4, 2023. A 30-day scoping comment period was held from Oct. 4, 2023 through Nov. 3,2023. Reclamation hosted two open-house style virtual public webinars during the scoping comment period.

On Dec. 5, 2023 Reclamation released a Scoping Summary Report that includes, the scoping process, a summary of the scoping comments, and a summary of the key themes and resource issues identified during scoping.

#### Public scoping webinars

###### Wednesday, Oct. 18, 2023

###### Friday, Oct. 20, 2023

- Public scoping webinar presentation **Link is to a PDF file
- 2023 Scoping Summary Report **Link is to a PDF file

                    - Grand Canyon Trust
                    - Morgan Sjogren
                    - Lower Colorado River Basin States
                    - Central Arizona Project
                    - Save the Colorado, Living Rivers and Colorado Riverkeeper
                    - U.S. Environmental Protection Agency
                    - American Rivers
                    - USFWS
                    - Central Utah Water Conservation District
                    - Colorado River Basin States
                    - Arizona Electric Power Cooperative, Inc
                    - Colorado River Commission of Nevada
                    - Upper Colorado River Commission
                    - Grand Canyon Wildlands Council
                    - Irrigation and Electrical Districts Association of Arizona
                    - Colorado River Indian Tribes
                    - Walt Anderson

                    - Upper Division States
                    - Salt River Project
                    - Center for Biological Diversity
                    - Arizona Game and Fish Department
                    - National Parks Conservation Association
                    - National Park Service
                    - BlueRibbon Coalition
                    - Upper Colorado River Commission
                    - Utah Municipal Power Agency
                    - Western Area Power Administration
                    - Wyoming Municipal Power Agency
                    - Pueblo of Zuni
                    - Grand Canyon River Guides
                    - Colorado River Energy Distributors Association
                    - Hopi Tribe
                    - Western Area Power Administration (Public Meeting)
                    - Colorado River Energy Distributors Association (Public Meeting)

### Next Steps

A final supplemental EIS with Record of Decision, as appropriate, is anticipated to be available by early summer 2024.

----

## Program Background

Since Glen Canyon Dam was completed in 1963, increasing concern was expressed by the public and federal and state agencies regarding how dam operations may be adversely affecting the downstream environment. To begin addressing these growing concerns, in December 1982, the Bureau of Reclamation initiated the multi-agency interdisciplinary Glen Canyon Dam Environmental Studies at the direction of the Secretary of the Interior.

In November 1989, the Secretary directed an Environmental Impact Statement  be prepared on the operation of Glen Canyon Dam, and the Secretary designated Reclamation as the lead agency. This Final EIS, completed in March 1995, received broad and intense interest from water and power users, environmental and conservation groups, Federal and State agencies, Indian tribes, and private citizens across the country.

Findings from the EIS indicated that many uncertainties still exist regarding the downstream impact of water releases from Glen Canyon Dam. The EIS team consolidated the issues of public concern, identifying the significant resources and associated issues to be analyzed in detail. These resources include: water, sediment, fish, vegetation, wildlife and habitat, endangered and other special status species, cultural resources, air quality, recreation, hydropower, and non-use value.

In compliance with the Grand Canyon Protection Act  of 1992 (Public Law 102-575), the EIS proposed a process of "adaptive management" whereby the effects of dam operations on downstream resources would be monitored and assessed.

The Act, and the EIS are the guiding documents for development of the Adaptive Management Program. The program meets the purpose and strengthens the intent for which the EIS was prepared, and ensures the primary mandate of the Act is met through future advances in information and resource management.

Section 1802 of the Act directed the Secretary to establish and implement long-term monitoring programs and activities to ensure the Glen Canyon Dam is operated "... in such a manner as to protect, mitigate adverse impacts to, and improve the values for which Grand Canyon National Park and Glen Canyon National Recreation Area were established, including, but not limited to natural and cultural resources and visitor use."

In order to comply with the consultation requirement of the Act, Section 1805 of the Act, the EIS recommended formation of a federal advisory committee. The Transition Work Group was formed to operate until such time as a federal advisory committee could be formed, and a Record of Decision  signed  by the Secretary of the Interior to initiate a process of "management" (operating criteria for unbiased scientific research and data collection) whereby the effects of dam operations on downstream resources would be assessed. Meetings were held with representatives  from the cooperating agencies and public interest groups who provided  comments on the criteria for development of reasonable alternatives for the EIS.

The transition group worked on a variety of issues including a long-term monitoring and research  program to ensure Glen Canyon Dam is operated in a manner consistent with protecting the downstream environment as well as implementation and management of operations and monitoring in consultation with broad-based interests.

The Record of Decision was signed by the Secretary of Interior in October 1996, and in January 1997, Interior Secretary Babbitt signed a Notice of Establishment of the Glen Canyon Adaptive Management Work Group, a federal advisory committee. The charter of this group was signed on January 15, 1997.

All of the elements are now in place for an effective, credible adaptive management effort. The Adaptive Management Work Group is the key; the Technical Work Group providing detailed guidance on issues and objectives; the Science Center to conduct the research and monitoring needed to evaluate operations; and the independent review panel, the outside review necessary to provide the credible science.

The AMWG continues public involvement in the decision-making process and incorporates those stakeholders with interest in the operation of Glen Canyon Dam and downstream resources. By blending the best science and management practices, the AMWG makes recommendations to the Secretary on how to protect the resources and meet the requirement of the law.

The Adaptive Management Program is administered through a senior Department of the Interior official — designee — and facilitated through the AMWG, which is organized as a federal advisory committee and chaired by the designee.

The AMWG held their first meeting on September 10-11, 1997, and officially formed the Glen Canyon Technical Work Group as a subgroup to work on tasks charged to them by the AMWG.
Back to Quick Nav **

----

## Contact us

**Bureau of Reclamation**    William (Bill) Stewart    125 South State Street, Room 8100    Salt Lake City, Utah 84138-1147** wstewart@usbr.gov

**Grand Canyon Monitoring & Research Center**      Serena Mankiller      2255 North Gemini Drive      Flagstaff, Arizona 86001** 928-556-7094      Fax: 928-556-7092** smankiller@usgs.gov

Back to Quick Nav **

----

## Related Documents

### Current Focus

                  - GT Max Model Review Panel Final Report **Link is to a PDF file
                  - GT Max Model Review Panel Workshop Participant Comments **Link is to a PDF file
                  - GT Max Expert Review Panel Response to Comments **Link is to a PDF file
                  - Adapitive Management Work Group Charter **Link is to a PDF file  - Sept. 2023
                  - Memorandums and Review - Desired Future Conditions **Link is to a PDF file
                  - Adapitive Management Work Group Operating Procedures **Link is to a PDF file
                  - Technical Work Group Operating Procedures **Link is to a PDF file

### Law of the River

                  - Colorado River Compact
                  - Boulder Canyon Project Act
                  - California Seven Party Agreement
                  - Mexican Water Treaty
                  - Upper Colorado River Basin Compact
                  - Colorado River Storage Project Act
                  - Arizona v. California et al.
                  - Colorado River Basin Project Act
                  - Criteria For Coordinated Long-Range Operation of Colorado River Reservoirs
                  - Minute 242 of the U.S. - Mexico International Boundary and Water Commission of 1973
                  - Colorado River Basin Salinity Control Act

### Reports to Congress on Glen Canyon Dam operations

Can be found on our Reports page in the new Document Library. 

### Reports and Recomendations to the Secretary of the Interior

                  - December 22, 2020 **Link is to a PDF file
                  - December 7, 2016 **Link is to a PDF file
                  - November 12, 2015 **Link is to a PDF file
                  - September 29, 2014 **Link is to a PDF file
                  - December 9, 2013 **Link is to a PDF file
                  - January 15, 2013 **Link is to a PDF file
                  - April 30, 2012 **Link is to a PDF file

Back to Quick Nav **

----

## Stay Connected

Want to stay current on all the activities of the Glen Canyon Dam Adaptive Management Program?

 Request to join our mailing lists.

 Simply email your first and last name, organization or agency affiliation, and the email address you want to receive the update to bor-sha-ucr-gcdamp@usbr.gov

*Last Updated: 4/10/24*

## More Information about the Bureau of Reclamation

## Stay in Touch

          -   
          -   
          -   
          -   
          -   
          -   
          -   

          - Contact Us
          - Site Index
          - Accessibility
          - Disclaimer
          - DOI
          - FOIA
          - No Fear Act
          - Notices
          - Privacy Policy
          - Quality of Information
          - Recreation.gov
          - USA.gov