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Denver Water, Boulder County strike agreement to address construction impacts, improve road safety, and enhance environment, open space and recreation as part of reservoir project

Denver — Wednesday, Nov. 3, 2021 Denver Water and Boulder County have entered into an agreement related to the Gross Reservoir expansion that marks the final step in a nearly 20-year federal, state and local review to permit the project. Denver Water will commit nearly $13 million and make significant adjustments to construction practices to address 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. In exchange, Boulder County agrees that the project may proceed, with construction expected to begin in April 2022. 

 “We appreciate the County’s effort to work through the issues and come to an agreement that will help ease concerns about the project’s impact on nearby residents, bring benefits to Boulder County residents through enhancements to its trails and open spaces and allow Denver Water to proceed on an undertaking critical to the water security of 1.5 million people in the Denver region,” said Denver Water CEO/Manager Jim Lochhead. “Denver Water and Boulder County have shared values. We both believe deeply in the need to address climate change, conserve our water resources and protect the region’s precious environment. This agreement reflects those values through dedicated funding and actions on the ground.” 

The settlement puts to rest a federal lawsuit filed by Denver Water in July, asking the court to resolve a conflict centered around whether Boulder County has any land-use permitting authority over the project given the Federal Energy Regulatory Commission’s order requiring Denver Water to proceed with expansion of the reservoir.  

The agreement includes numerous components across multiple areas of emphasis. They include: 

Reducing construction and traffic impacts

  • $5 million to be administered by Boulder County to address specific concerns that may arise over noise, light and dust impacts to residents near the project.  
  • Steps to reduce haul traffic on area roads, including development of an on-site quarry (later to be largely submerged by the reservoir), restrictions on hours when travel and work can occur on local roadways and other efforts to limit congestion. 
  • Permanent improvements to some roads and intersections. 
  • Traffic reduction efforts to include a rideshare program that creates incentives for workers to carpool from a staging area below Coal Creek Canyon, and certain “no truck” days. 

Environmental and recreational enhancements

  • Transfer of 70 acres of Denver Water land near Walker Ranch Open Space to Boulder County, with deed restrictions limiting it to open space and conservation uses, along with easements over utility-owned land to allow for trail connections through the reservoir area. 
  • $5.1 million for use in acquiring land for open space, conservation easements and trail corridors. 
  • $1 million for restoration of the South Saint Vrain Creek on the Hall Ranch Lyons Quarry site; any remaining funds from the project can be used for other creek or wetland projects in the South Boulder Creek watershed. 
  • $250,000 over the five-year construction period for use by Boulder County for additional rangers, communication staff, signage and shuttles to address recreational closures during construction, 

Commitments to conservation and climate action

  • $1.25 million to offset carbon emissions estimated to be generated by the project, even as Denver Water notes those emissions will be offset over time by the hydropower produced by the dam. The county will invest the funds in various emissions reductions projects. 
  •  $250,000 toward a pilot program to explore using “biochar” to reduce the carbon emissions related to tree removal associated with the project.  
  • Use of hydropower to operate most of the construction project and fly ash or other natural constituents in the concrete, which reduces CO2 production. 
  • Continued work by Denver Water to conserve and reduce water use, spanning programs that include recycled water, limits on summer water, tiered rate structures and efficiency improvements at the customer-by-customer level. 

Denver Water has worked earnestly for years with local governments and citizen groups on the West Slope to address the impacts of an expanded Gross Reservoir. Those talks, often intense, and spanning half a decade, resulted in the Colorado River Cooperative Agreement in 2013, an unprecedented collective effort involving 18 signatories and 40 partner organizations that began a new era of collaboration and conflict-resolution between Denver Water and the West Slope to provide environmental benefits and protections for the Colorado River watershed.

The utility also made — and in many cases has already carried out — additional commitments worth tens of millions of dollars to offset impacts of the reservoir expansion in conditions attached to permits issued by the U.S. Army Corps of Engineers and the Federal Energy Regulatory Commission, as well as through separate agreements with the U.S. Forest Service. 

Previous commitments have also included projects of direct benefit to Boulder County: raising the dam by an additional 6 feet to create 5,000 acre-feet of storage space in Gross Reservoir for environmental flows in South Boulder Creek as well as to bolster water supplies for the cities of Boulder and Lafayette, greater production of clean energy from the hydroelectric facility at Gross Reservoir, improvements to portions of South Boulder Creek damaged in the 2013 floods and expanded recreational opportunities at the reservoir. 

“In the two decades Denver Water has spent preparing for the project, we have been driven by a singular value: the need to do this expansion the right way, by involving the community, by upholding the highest environmental standards and by protecting and managing the water and landscapes that define Colorado,” Lochhead said. “Boulder County and its residents share these perspectives, and we look forward to continuing to work with them as the project moves ahead.”  


Denver Water proudly serves high-quality water and promotes its efficient use to 1.5 million people in the city of Denver and many surrounding suburbs. Established in 1918, the utility is a public agency funded by water rates, new tap fees and the sale of hydropower, not taxes. It is Colorado’s oldest and largest water utility. Subscribe to TAP to hydrate your mind, and follow us on Facebook, Twitter and Instagram.