The Gross Reservoir Dam Expansion: Denver Water v. Boulder County
After a multi-year legal battle over the Gross Reservoir Dam Expansion, Boulder County and Denver Water settled on a $12.5 million agreement. For Boulder County, this decision was not the favored outcome.
Nestled in the mountains, about 26 miles from Boulder via Flagstaff road, Gross Reservoir holds a portion of the Denver Metro areaâs water supply.
The reservoir was built in 1954 by Denver Waterâs former Chief Engineer Dwight D. Gross, and after 67 years, Denver Water plans to renovate the dam to address current and future water imbalances. Boulder County raises concerns over the projectâs environmental impacts, and questions about its call for more water.
On July 14, 2021, Denver Water sued Boulder County claiming that local authorities are prolonging the implementation of a federally permitted project. For two decades this project has been in contention, but on Nov. 2, 2021 the Board of County Commissioners settled with Denver Water to pay $12.5 million to mitigate the expansionâs environmental impact.
Both the Boulder County commissioners and environmental groups are not pleased with the outcome.
"We believe the settlement agreement is the best we can get from Denver Water to help compensate our constituents and the environment.â
âWe understand that settling with Denver Water is not acceptable to many of our constituents. It isnât the outcome we would have liked to see,â said Commissioner Claire Levy in a public statement. âUnfortunately, Boulder County was not in control of this process, and despite our best efforts, a far worse outcome is the most likely result of rejecting the offer. It would have been reckless not to consider an offer that offset at least some of the destructive impacts of this project. Under these circumstances, without a full public consideration of this project through our local review process, we believe the settlement agreement is the best we can get from Denver Water to help compensate our constituents and the environment.â
Currently, the top of Gross dam reaches 340 feet and the reservoir is 41,811 acrefeet by volume. To increase water storage, construction efforts aim to add 77,000 acrefeet by raising the dam 131 feet, allowing for an additional 25 billion gallons to be stored.
In this expansion process, however, Dr. Gordon McCurry, Principal Hydrologist at McCurry Hydrology LLC, identified substantial flaws in Denver Waterâs environmental impact statement (EIS). He reviewed the purpose and need of the expansion and if the dam raise was the least âenvironmentally damaging practicable alternativeâ to water imbalances. âI found that both the âpurpose and needâ wasnât valid and that this was not the least environmentally damaging practicable alternative,â he said.
The citation from Denver Water claimed that âProjected metro Denver demand will increase by 134,000 acre-feet to 280,000 acre feet by 2050 against a 2015 baseline and [the Denver metro] area likely will experience a supply shortfall, even accounting for the Gross Reservoir expansion and other water projects, a drop in per-capita use and further conservation and reuse.â
The validity of this claim was challenged in light of the outdated information, collected in 2010, that was presented in the EIS. In Dr. McCurryâs memo (or review of the project) to the Federal Energy Regulatory Commission (FERC), he identifies that Denver Waterâs demand projections are much higher than the 2010 water use. In addition, water use has also trended downwards since 2010, even as Coloradoâs population increased.
âSome of the information is 15 plus years old, and they never bothered to update it, because I guess if they had, then they wouldnât have been able to suggest that there is a purpose and need,â Dr. McCurry said. Denver Water âprobably assumed that the people at the Corps of Engineers or the FERC werenât going to dig into the details, they were just going to read what the report said and go, âOkay, approved,â which is basically what happened.â
In order to manipulate federal land, Denver Water needed approval from the Army Corps of Engineers and the FERC. On July 6, 2017, the Army Corps of Engineers approved the Final Environmental Impact Statement (FEIS) on its purpose, need, and alternatives analysis. FEIS was completed on April 25, 2014, and after the Corps completed an environmental assessment (EA).
The FERC produced a Supplemental Environmental Assessment focusing on the effects of an amendment of the Gross Reservoir Project license in February of 2018.
Complaints on the FERCâs environmental assessment (EA) and the FEIS were brought to the FERCâs attention in a letter written on March 20, 2018, from Boulder County Attorney Ben Pearlman. âThe FERC should determine that both the FEIS and the EA fail to meet the standards of the National Environmental Policy Act (NEPA) and therefore reject staffâs unreasonable approach,â Pearlman wrote.
NEPAâs standards require organizations like Denver Water to apply the âleast environmentally damaging practicable alternativeâ to projects. According to Dr. McCurryâs review, Denver Water proposed five alternatives that attempt to meet standards, but the alternatives cause considerable loss of rare vegetation, wetlands, and habitats.
Boulder County disputes the FERCâs staff advising process of overlooking environmental impact and deciphering a need for the project. âSince Denver Water initiated its effort to construct the project, Boulder County has become increasingly concerned that Denver Waterâs preferred alternative [of raising the dam] does not meet the purpose and need Denver Water established for the project,â Pearlman wrote.
The FERC approved the project in 2020 regardless of Dr. McCurryâs memo, the Attorneyâs letter raising concerns and various comments from concerned citizens.
In this lawsuit, Denver Water presents a reasonable defense, despite Boulder Countyâs arguments to the contrary.
Jeff Martin is the project manager on the expansion. He said, âColorado is expanding, and Denver Water provides water to 25% of the state. We need to make sure that we can meet that future demand, or more importantly, we need to make sure we have a resilient system. So, engineers and planners like that resiliency; that means we can deal with uncertainty and risk that is going to occur in the future. In this case, that risk is in the forms of drought, climate change, and increasing wildfires...We not only needed to meet future demand, we needed more water in strategic locations.â
Ninety percent of Denver Waterâs water supply lives in the south collection system, and only 10% resides in the north system. Theyâre concerned that too much of the supply is consolidated in the south, which puts the south system and thus Denver Water as whole in a position that is vulnerable to natural catastrophe.
According to Martin, in their discussions with the Corps, the Gross Reservoir expansion was the least environmentally damaging practicable alternative. The Corps advised that raising an existing dam caused less environmental impact than building new facilities.
Continuing with the environmental discussions, the Corps provided Denver Water with requirements to mitigate impacts of the project, such as flooding of the wetlands and Boulder Creek. âA big project Denver Water had, which was called Two Forks, was vetoed by the EPA and environmental groups that were against the project actually pointed to gross reservoir saying, âHey, a responsible project to do would be raising the existing dam like Gross Reservoir,â and here we are 20 years later doing exactly what was suggested that we do.â
In the legal disputes, Boulder County pushed the 1041 process, also known as the Areas and Activities of State Interest Act. The process was enacted in 1974 and allows local governments to regulate, through specific criteria, a variety of development projects. Boulder County wanted to cease the project through the 1041 process, but the county did not have the authority to review the plan because the FERC approved the project in 2020.
âThis project represents outdated planning and thinking. Unfortunately, instead of using our land use process to review this project to address the concerns we heard from the public, we are faced with trying to address these issues in a legal arena with a large corporation that holds all the power within the legal framework. Being put in a position that does not allow us to stop the expansion of the Gross Reservoir and Dam is heart-wrenching and very unsatisfying to us as elected officials and as stewards of public health and safety,â said Commissioner Loachamin in a statement.
Commissioners agreed with the concerns of the project. Due to the hydroelectric generation being controlled by federal law, however, the county had to settle on the terms that Denver Water will apply the most environmentally practicable alternatives moving forward.
âI wouldnât be working on [the expansion] if I didnât think Denver Waterâs values were in line with my own on protecting the natural environment,â Martin said. âI can assure you this carries on for me to our CEO, to our board, to everybody at Denver Water that we have been entrusted with managing a huge, valuable resource. And we take that very seriously, and we want to do it the right way.â
Photos by Elliot Whitehead