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Project review and permitting

Raising a dam - RCC Stay informed Project review and permitting

Like many water supply projects, the Gross Reservoir Expansion Project has undergone multiple federal, state and local permitting and review processes over the past two decades. These reviews included the purpose and need for the project, as well as environmental impacts and mitigation. An overview of each permit or review process is below. 

Throughout the permitting process, Denver Water has been driven by a singular value: the need to do this expansion the right way, by involving the community; upholding the highest environmental standards; providing a sustainable, high-quality water supply to our customers; and protecting and managing the water and landscapes that define Colorado. 

Federal permitting 

Endangered Species Act, Section 7 Consultation; finalized December 2013

The U.S. Fish and Wildlife Service is tasked with the management and conservation of fish, wildlife, plants and their habitat. They do this through a variety of actions, including issuing biological opinions like the ones related to this project, as well as enforcing the Endangered Species Act and Migratory Bird Treaty Act. 

In December 2013, the U.S. Fish and Wildlife Service issued its biological opinion on impacts of depletions of Denver Water’s entire system (not just the Gross Reservoir Expansion Project), including the Platte and Colorado River basins. The biological opinion considered impacts to all federally listed threatened or endangered species, including the Preble’s meadow jumping mouse, whooping crane and Colorado pikeminnow, among others. 

A second biological opinion was issued in June 2016, regarding impacts to greenback cutthroat trout. These impacts were limited to four streams in Denver Water’s collection system that contain self-sustaining populations of green lineage cutthroat trout, a species that the U.S. Fish and Wildlife Service had been treating as protected under the Endangered Species Act while genetic studies of cutthroat trout in Colorado were conducted. After those studies were completed, Colorado Parks and Wildlife and the U.S. Fish and Wildlife Service concluded that green lineage cutthroat trout are genetically distinct from the Endangered Species Act-listed greenback cutthroat trout and rescinded the 2016 biological opinion. 

U.S. Forest Service Agreement; finalized July 2016

The U.S. Forest Service is tasked with sustaining the health, diversity and productivity of the nation’s forests for current and future generations. In September 2016, Denver Water and the forest service reached a settlement agreement to address past, current and future impacts of the project. The three-part agreement identifies funding and projects to protect and preserve forest service resources. It includes:

  • Settlement agreement — The primary agreement describing the negotiations between the U.S. Forest Service and Denver Water and resolution of issues pertaining to effects to forest service lands and resources from Denver Water’s construction of Gross Reservoir Expansion project and post-construction operations. As part of this agreement, Denver Water will convey 539 acres of wetlands, meadows and forests in Gilpin County to the U.S. Forest Service to be managed for public use.
  • Appendix 1 – 4(e) Conditions — Conditions guiding the construction, operation and maintenance of the Gross Reservoir Expansion Project enacted as part of the Federal Energy Regulatory Commission Order in 2020 to protect resources on forest service lands.
  • Appendix 2 – Off-license Agreement — Environmental commitments by Denver Water and the U.S. Forest Service related to Denver Water’s past, current and future operations on forest service lands.

Record of Decision and 404 Permit; received July 2017

The U.S. Army Corps of Engineers is charged with administering the permitting program under Section 404 of the Federal Water Pollution Control Act of 1972, also known as the Clean Water Act. Permit review and authorization encourages project proponents to protect aquatic environments through the following:

  1. Avoidance of impacts 
  2. Minimizing unavoidable impacts
  3. Requiring mitigation for unavoidable impacts

In 2003, Denver Water submitted a request to the Corps for the Moffat Collection System Project to consider alternatives to meet Denver Water’s purpose and need for additional water storage in Denver Water’s North System.

Specifically, the purpose of the Moffat Collection System Project was to develop 18,000 acre-feet per year of new, annual firm yield, to address two major issues:

  1. Overall near-term water supply shortages
  2. The imbalance in water storage and supply between Denver Water’s North and South systems.

Expanding Gross Reservoir was one of six practicable alternatives, including a No Action alternative, developed by the Corps alternative analysis.  

The Corps, the lead federal agency with jurisdiction over the project, considered the request under Section 404 of the Clean Water Act and determined that an Environmental Impact Statement must be prepared under the National Environmental Policy Act. The NEPA process allowed the Corps to evaluate a range of alternatives to analyze natural and human environmental effects of the project. Cooperating agencies in the NEPA process included the U.S. Environmental Protection Agency, the Federal Energy Regulatory Commission, the State of Colorado Department of Natural Resources and the Colorado Department of Public Health and Environment. The Corps granted consulting agency status to Grand County relative to effects on county resources. The Corps offered the U.S. Forest Service cooperating agency status; it declined and participated through standard agency consultation. 

The Draft Environmental Impact Statement was released in October 2009 and examined the human and environmental impacts of five alternatives to meet the purpose and need for the Moffat Collection System Project. The Draft EIS also evaluated the impacts of a No Action alternative. The Draft EIS was released for a public and agency comment process, which closed in March 2010. As a result of the comment process, the Corps collected additional information and revised the Draft EIS. 

In April 2014, after further agency coordination and a request from Denver Water to work with stakeholders to further refine the mitigation plan presented in the Draft EIS, the Corps released the Final EIS. This document detailed project mitigation measures and addressed public comments received after publication of the Draft EIS and, along with public comments, served as a basis for the Corps’ decision on whether to issue a Section 404 Permit.

In July 2017, the Corps approved the Moffat Collection System Project by granting Denver Water a Section 404 permit. The Corps issued a Record of Decision, selecting the Least Environmentally Damaging Practicable Alternative to meet the purpose and need for the project, which was for the expansion of Gross Reservoir

Federal Energy Regulatory Commission Hydropower License Amendment; received July 2020

The Gross Reservoir Dam includes a 7.6 megawatt hydropower unit, licensed for operation by the Federal Energy Regulatory Commission. Under the Federal Power Act, FERC has exclusive authority to license nonfederal hydropower projects. The license amendment process requires FERC to consider and address the economic, engineering, environmental and socioeconomic effects of project development and operation.

In November 2016, Denver Water filed a final license amendment application with FERC. The 60-day public comment period started in February 2017. Public comments were submitted and considered throughout the process. 

In April and May 2017, Denver Water provided FERC with additional information, including details about its consultation with the U.S. Forest Service regarding changes to the recreation management plan and responses to public comments

FERC published a notice of availability of a Supplemental Environmental Assessment in February 2018 and accepted public comment through April 2018. The following year, FERC published the Final Supplemental Environmental Assessment, including the Finding of No Significant Impact. 

In July 2020, FERC issued an order to proceed with design and construction to expand Gross Reservoir in Boulder County. The order required Denver Water to develop plans in accordance with the articles and conditions in the order to further protect the public and environment, such as plans for tree removal and traffic management. These plans are listed in the document library

State permitting 

Fish and Wildlife Plans; approved June 2011

Under Colorado law, fish and wildlife resources impacted by water development projects are a matter of statewide concern, and proponents of water diversion, delivery or storage projects are expected to mitigate the future impacts of their projects on such resources. To do so, project proponents are required to develop a fish and wildlife mitigation plan.

In 2011, Colorado Parks and Wildlife and the Colorado Water Conservation Board approved the fish and wildlife mitigation plan. The plan defined measures to mitigate impacts to fish and wildlife resources, including a financial commitment to Colorado Parks and Wildlife for a fish barrier, in a location of their choosing, to protect native cutthroat trout.  

Denver Water also voluntarily prepared a fish and wildlife enhancement plan to address concerns raised by Colorado Parks and Wildlife and other stakeholders regarding the condition of the aquatic ecosystem in the Upper Colorado River. This plan includes stream restoration projects, with long-term monitoring, to improve the aquatic habitat along approximately 14 miles of the Upper Colorado River from the Windy Gap Diversion to the lower terminus of the Kemp-Breeze State Wildlife Area. 

National Historic Preservation Act, Section 106 Consultation; finalized October 2015

In October 2015, Denver Water and the State Historic Preservation Office reached a programmatic agreement with the U.S. Army Corps of Engineers following a consultation process to meet obligations set forth in the National Historic Preservation Act. This act requires any federal funding, licensing or permitting that may affect cultural resources must consult with the state historic preservation officer in what is known as a Section 106 Consultation

A second programmatic agreement was established in 2018 between the state historic preservation officer and Federal Energy Regulatory Commission. These agreements establish a process to support cooperation between Denver Water and state and federal agencies to identify and document historic and archaeological features within the project area. The agreements also set a procedural framework for Denver Water to follow in the event historic features or archaeological resources are discovered while work on the Gross Reservoir Expansion Project is underway.

Section 401 Certification; received June 2016

Section 401 certification, which is a component of the Clean Water Act, is a process managed at the state level. Regarding the Gross Reservoir Expansion Project, the Colorado Department of Public Health and Environment is responsible for evaluating the impacts of, and ensuring water quality is not impacted by, this project.

In June 2016, CDPHE issued the Section 401 Water Quality Certification for the Project. The certification states that — with the approved mitigation and enhancement measures — the project will create a “net environmental benefit to the state’s water quality” on both the West and East slopes. The Section 401 certification includes a system certification letter, an analysis of narrative temperature standards for South Boulder Creek, guidance for voluntary pilot projects, and the rationale for the Conditional 401 certification.

Local permitting

Boulder County Settlement Agreement; settled December 2021

Typically, federal and state permits authorize proposed developments or projects while local permits enforce building codes and compliance. Colorado House Bill 1041, also known as the Areas and Activities of State Interest Act, was enacted in 1974 and allows local governments to regulate, or designate conditions on, a variety of development activities, with guidance from the state.

Boulder County’s 1041 regulations are listed in Article 8 – Location & Extent Areas & Activities of State Interest.

In September 2020, Boulder County accepted Denver Water’s 1041 application. The full docket can be found on Boulder County’s Community Planning and Permitting website

Boulder County reviewed the 1041 application, solicited comments from interested parties, and submitted comments to Denver Water. Comment responses were prepared by Denver Water and returned to Boulder County. After a series of comments and response cycles, Denver Water filed a lawsuit in U.S. District Court against Boulder County on July 14, 2021, asserting the county was overreaching its authority and jeopardizing the federally ordered expansion

On Nov. 3, 2021, Denver Water and Boulder County entered into an agreement that resolved Denver Water’s federal lawsuit against the county. The settlement agreement was entered into in lieu of a 1041 Permit. Per the agreement, Denver Water will commit nearly $13 million to Boulder County, including $5 million in a mitigation fund to offset disruptions to local residents. The settlement agreement also requires Denver Water to make significant adjustments to construction practices, responding to the county’s concerns over impacts to the local community and environment, as well as provide a contribution of land to Boulder County’s open space inventory. The full settlement agreement is posted on Boulder County’s Gross Reservoir Expansion webpage.  

For information on the mitigation fund, please contact

Other state and local permits

The Gross Reservoir Expansion Project also has received several other state and local construction, zoning and building permits. These permits were coordinated with the appropriate state and local agencies. They detail construction activities and mitigation measures for resources, including access and roadway, stormwater, grading, wastewater, air quality, building, and other resource and land development permits.