Town of Saguache opposes water export plan — Center Post-Dispatch

Saguache Creek

From The Center Post-Dispatch (Teresa L. Benns):

Sean Tonner with Renewable Water Resources (RWR), who is peddling a water export plan he says is finding support among farmers and ranchers in the Valley, presented his plan to the town of Saguache last month during a town board meeting.

A former chief of staff for Gov. Bill Owen, who supported the plan, Tonner also worked with former State Senator Greg Brophy and other government officials on the project. Currently Tonner owns the 11,500-acre Gary Boyce ranch, purchased from Boyce’s wife following his death. He also leases grazing land in the same area. Tonner says he will retire the water rights for 3,000 of those acres.

He also said he could possibly retire the water rights to, for example, North Star Farms, and other area farms and ranches.

Tonner claims less than two percent of the annual confined aquifer recharge — 500,000 acre-feet — is needed by the Front Range. Farmers could sell all or a portion of their water rights to RWR for twice the going amount. A total of $60 million has been set aside to procure water rights.

Already enough Saguache County farmers and ranchers have agreed to sell their water rights to satisfy the proposed 22,000 acre-feet project, Tonner reported. The plan is said to be able to retire more than 30,000 acre-feet, reducing the overall usage from the Basin. This would presumably lessen the pressure on existing rivers and streams now providing water to the Front Range.

A pipeline along Highway 285, restricted to a 22,000-acre-foot capacity, would carry the water up over Poncha Pass into Chaffee County and from there it would eventually make its way into the Platte River. There would be no adverse impact on wildlife, Tonner claims.

The project would create a $50 million community fund for the county that could be used for a variety of purposes including education, law enforcement, tourism, economic development, conservation and other worthy cause. The county would manage the fund. Just the interest would generate $3-4 million annually, twice the amount of the county’s sales tax grants.

The board just happened to have a resolution on its agenda that evening to oppose the export plan, and following Tonner’s presentation, informed him of the upcoming vote. But before the vote was taken, a guest in the crowd asked to speak. He had flown in all the way from California just to attend the meeting.

Opposition to the plan

Case Vandereyk. addressing Tonner, announced that he was the owner of North Star Farms and told those attending the meeting he had “no interest” in selling his water rights and was basically opposed to the plan. “I never talked to anyone about selling my water rights,” he concluded. His statement was met with resounding applause from the audience.

In his first appearance in the Valley following the 2018 election, Attorney General Phil Weiser cautioned Valley residents to view RWR’s proposals to pump water from the Valley “very skeptically” citing legal, economic, and ecological concerns. Former Secretary of the Interior Ken Salazar, whose family has farmed in the Valley for generations, also strongly opposes the plan.

Cleave Simpson, with the Rio Grande Water Conservation District, formally opposes the plan and has stated that no matter what farmers and ranchers are offered for their water, he believes they will not sell.

Later on in the meeting, following Tonner’s presentation, the Saguache Town Board passed a resolution opposing the water transport project.

Colorado transmountain diversions via the State Engineer’s office

#Aurora, #ColoradoSprings seek to drill on lower Homestake Creek dam sites — @AspenJournalism #ColoradoRiver #EagleRiver #CORiver #aridification

Homestake Creek, flowing toward the Eagle River, near the Alternative A dam site being studied by Aurora Water and Colorado Springs Utilities, about three miles up Homestake Road from U.S. 24. The photo was taken on July 13, 2019. Photo credit: Brent Gardner-Smith/Aspen Journalism

From Aspen Journalism (Brent Gardner-Smith):

The cities of Aurora and Colorado Springs are increasing their efforts to develop a reservoir on lower Homestake Creek in the Eagle River basin that would hold between 6,850 acre-feet and 20,000 acre-feet of water.

The two Front Range cities, working together as Homestake Partners, have filed an application with the U.S. Forest Service to drill test bores at four potential dam sites on the creek, renowned for its complex wetlands.

They briefed members of Colorado’s Congressional delegation in April about federal legislation they are drafting that would adjust the Holy Cross Wilderness boundary near the dam sites.

And Aurora spent $4.1 million in 2018 to purchase a 150-acre private inholding parcel that accounts for about half the surface area of the 20,000-acre-foot version of the reservoir, removing one obstacle in the way of submitting a comprehensive land-use application to the Forest Service.

“We are in preparation to permit this overall project, to try and get that larger application in, so every piece of the project has had more time and effort spent on it,” said Kathy Kitzmann, a water resources principal with Aurora Water.

One of four potential dam sites on lower Homestake Creek, about four miles above U.S. 24, between Minturn and Leadville. From this location, the dam that forms Homestake Reservoir higher up the creek can be seen. Photo credit: Brent Gardner-Smith/Aspen Journalism

Eagle River MOU

The Whitney Reservoir project is defined in part by the Eagle River Memorandum of Understanding, a 1998 agreement that gives Aurora and Colorado Springs a basis to pursue 20,000 acre-feet of water from the Western Slope.

Parties to the MOU include Aurora, Colorado Springs, Climax Molybdenum Co., Colorado River Water Conservation District, Eagle River Water and Sanitation District, Upper Eagle Regional Water Authority, and Vail Associates.

Peter Fleming, the River District’s general counsel, told the district’s board in a July 1 memo that the River District is “not participating in any Homestake Creek based alternative at this time, this effort is now being carried forward solely by the Homestake Partners.”

Under the MOU, various parties can pursue projects on their own, and the other parties are bound to support those efforts, but only to the degree that a proposed project meets the objectives of the MOU, including whether a project “minimizes environmental impacts.”

A view, from the Alternative A dam site, of the Homestake Creek valley. The triangle shape in the distance is the dam that forms Homestake Reservoir. Photo credit: Brent Gardner-Smith/Aspen Journalism

Serious intent

Whitney Reservoir takes its name from Whitney Creek, which flows into Homestake Creek just above the four potential dam alignments now being studied. The dam that would form Whitney Reservoir would stand across Homestake Creek, not Whitney Creek. Homestake Creek flows into the Eagle River at Red Cliff.

Asked how serious the two cities are about the Whitney Reservoir project, Kevin Lusk, the principal engineer at Colorado Springs Utilities, said, “We’ve been serious about it for the last 20 years.”

And he said the recent drilling application “is another step in the continuum from concept to reality.”

On June 25, the two cities submitted an application with the Eagle-Holy Cross Ranger District for permission from the White River National Forest to drill 13 test bores 150 feet to explore the geology under the four sites.

The sites are clustered on the creek between 3 and 5 miles above the intersection of U.S. 24 and Homestake Road, shown as Forest Road 703 on most maps. The intersection is not far below Camp Hale, between Minturn and Leadville.

The drilling application says Aurora and Colorado Springs are conducting “a fatal-flaw level reservoir siting study” that “comprises subsurface exploration to evaluate feasibility of dam construction on lower Homestake Creek.”

White River National Forest supervisor Scott Fitzwilliams said review of the drilling application itself is “fairly standard stuff.”

“We’ll definitely send out a scoping statement, asking for public comment, but it won’t be about a dam,” he said. “It will be about drilling the holes.”

Each of the 13 borings would take up to five days to drill, so there could be 65 days of drilling this fall or, if the application is not approved this year, in 2020, according to Lusk.

The project includes taking a “track-mounted drill rig or a buggy-mounted drill rig,” a “utility vehicle pulling a small trailer” and a “track-mounted skid steer” onto public lands along 10-foot-wide “temporary access routes.”

The drill rigs are about 8 feet wide, 22 feet long and 8 feet high. To get the rigs to drilling sites, some wetlands may need to be crossed and trees will be cut as necessary.

The information about the geology under the four sites will help determine the size of a dam on a given alignment and how much water a reservoir would hold, Lusk said. And that could affect how much wilderness area might be encroached on.

A map prepared by Aurora Water that shows a potential 500-acre adjustment to the Holy Cross Wilderness boundary near the potential Whitney Reservoir on lower Homestake Creek. The map as current as of July 16, 2019.

Wilderness boundary

Given that Aurora and Colorado Springs are still working through various options, it’s not clear yet how big of an adjustment to the wilderness boundary they might ultimately seek from Congress.

The current proposed legislation developed by the cities asks to remove 497 acres from the wilderness boundary, but it is also expected to include a reversion provision so if all 497 acres are not needed, the boundary adjustment could be reduced.

According to Lusk, in one the of the alternatives studied, about 80 acres would need to be removed from the wilderness area if Whitney Reservoir was to hold 20,000 acre feet of water. However, the cities have yet to rule out the option of building an alternate reservoir below the Whitney Reservoir location – Blodgett Reservoir – which could require a larger boundary adjustment, although not the full 497 acres.

An adjustment to a wilderness boundary requires an act of Congress and the president’s signature. In April, representatives from the two cities described the potential boundary change to staffers of U.S. Sens. Michael Bennet and Cory Gardner and U.S. Reps. Scott Tipton, Jason Crow, Joe Neguse and Doug Lamborn.

Fitzwilliams said Monday the Forest Service won’t accept a full-blown land-use application for Whitney Reservoir until the wilderness boundary issue has been worked out through federal legislation, if that is still needed after the final version of the reservoir is better defined.

Kitzmann said she is reaching out to stakeholders to continue to refine the legislative language and the map showing the extent of the proposed boundary change.

A wetland area along Homestake Creek in an area that would be flooded by a potential Whitney Reservoir. Aurora and Colorado Springs, seeking to build the reservoir, have recently submitted a drilling application to the U.S. Forest Service to search for fatal flaws in the geology under four potential dam alignments. Photo credit: Brent Gardner-Smith/Aspen Journalism

Wetlands and fens

On another front, Aurora Water and Colorado Springs Utilities staffers are hosting a tour this week for the directors of the Colorado Water Conservation Board of the Homestake Plant and Fen Relocation Project, near Leadville.

The CWCB directors, holding their July meeting in Leadville, also will hear a presentation at their meeting about the fen-relocation effort, which consists of moving “fen-like organic soils and plant life” from one location in blocks or bales to another location and “reassembling them in a specially prepared groundwater-fed basin.”

Many regulatory agencies do not believe it’s possible to re-create complex fen wetlands, according to a CWCB staff memo, but that regulatory stance “may be related to the lack of scientific investigation on fen mitigation.”

A 2016 study estimated between 26 and 180 acres of wetlands on lower Homestake Creek would be impacted by Whitney Reservoir.

“This is one of the finest wetlands we can find on our forest — it’s unbelievable,” Fitzwilliams said. “From an environmental impact standpoint, this would not be a project that we would be favorable to.”

But Lusk said the fen-relocation project near Leadville is “proof of concept” that replacing fens, while “a tough nut to crack,” can be done.

Fitzwilliams may be hard to persuade.

“You can mitigate,” he said, “but you can’t replace 10,000 years of work.”

A map from Colorado Springs Utilities that shows how tunnels could bring water to Whitney Reservoir from Fall and Peterson creeks, and from the Eagle River. The map also shows the route of a pipeline to pump water from Whitney Reservoir to Homestake Reservoir.
Homestake Reservoir, which is partially in Pitkin County, but mainly in Eagle County. Below the reservoir the Homestake Creek valley is visible, as well as short section of what’s known as Homestake Road. Water held in the potential Whitney Reservoir would be pumped up to Homestake Reservoir and then sent to the Front Range. Photo credit: Brent Gardner-Smith/Aspen Journalism

Forebay and pumping

Despite the wetlands and wilderness challenges, Lusk and Kitzmann said no fatal flaws have been found yet in what they view as an important future element of their water-supply systems.

The new reservoir would serve as a collection point for water brought in via tunnels from the Eagle River and Fall and Peterson creeks, and for water captured from Homestake Creek.

The reservoir would also serve as a forebay, as the water captured in Whitney Reservoir would be pumped 7 miles up to Homestake Reservoir. Once there, it can be sent through a tunnel under the Continental Divide to Turquoise Reservoir, near Leadville, and then on to Aurora and Colorado Springs.

The two cities own and manage Homestake Reservoir, the upper end of which is in Pitkin County. The reservoir opened in 1967 and normally stores 43,600 acre-feet of water from seven high-mountain creeks behind a 231-foot-tall dam. About 25,000 acre-feet a year is sent through the Homestake Tunnel each year to the Front Range.

Homestake Partners also has a conditional water-storage right from 1995 to store 9,300 acre-feet of water behind a potential 110-foot-tall dam in what is called Blodgett Reservoir, located on Homestake Creek below the Whitney Reservoir sites. Blodgett Reservoir also has a longer history, and has been viewed as an alternate location for older water rights – appropriated in 1952 and adjudicated in 1962 – that are tied to Homestake Reservoir.

Aspen Journalism covers rivers and water in collaboration with The Aspen Times and other Swift Communications newspapers. The Times published this story on Wednesday, July 17, 2019. This version includes a clarification concerning the size of the adjustment to the wilderness boundary and the date of the water rights for Blodgett Reservoir.

Gross Reservoir Expansion Project update

Gross Dam enlargement concept graphic via Denver Water

From TheDenverChannel.com (Jace Larson):

The project will require significant construction over seven years to increase the reservoir’s holding capacity to 119,000 acre-feet of water.

When built, the dam will be the tallest in Colorado.

Denver Water says the additional space is needed to spread out capacity outside of Denver for the water utility used by 1.4 million people in the city and its surrounding suburbs.

The proposed construction project is not without opposition from neighbors and environmentalists who say they will endure years of construction on a water project that will never provide water to their taps.

“Boulder County is going to host this reservoir but gets no water from it. We derive no benefit from it. We only pay the price of having this thing in our county,” said Tim Guenthner, who lives just above the dam in a subdivision of about 1,000 people.

Denver7 decided to take a 360 look at this issue and gathered perspectives from five people connected to the proposed construction project…

Boulder County Commissioners have also taken a stance that Denver Water must get local permits before it can start the project.

Denver Water spokesman Travis Thompson said Denver Water doesn’t believe the law requires that and points out it has undergone numerous environmental studies and worked through the state permit process. This issue will likely be decided by another judge…

Denver Water’s Gross Dam project manager, Jeff Martin, acknowledges the project will cause noise for neighbors.

“Well we don’t hide from the fact there’s going to be some disruption from the noise, but we are looking at ways of minimizing that noise,” Martin said.

As an example, Denver Water decided to move the quarry needed to make cement to a portion of the lake that will be covered by water once more capacity is added. The original plan had the quarry on a portion of land jetting out into the lake.

Have an on-site quarry will also mean less truck traffic.

Martin said even with conservation efforts, Denver Water needs more capacity. He said experts have provided the water utility with data showing there will be 5 million more people in Colorado by 2050.

Denver water has 90% of its storage lakes west and south of the metro area, but only has 10% up north. This new dam project will add significantly more water storage north of the city.

“That’s important because if we have a catastrophic event or a drought in one of the systems, it leaves us depending on the other system,” he said. “What we want to do is create a little bit more balance and put more water in Gross Reservoir. This project is going to triple the size of the reservoir.”

[…]

Kirk Klanke is a member of Trout Unlimited, an environmental group seeking to protect and restore rivers across the country.

His perspective is one many wouldn’t expect from a member of the environmental group. He’s a supporter of the new dam.

“I think it’s extremely selfish to think we shouldn’t grow,” he said.

He says Denver Water has the legal right to build more capacity someplace. Gross Reservoir is the best option.

“Raising an existing dam has far less environmental damage than building a new one somewhere else,” Klanke said.

He says Denver Water has agreed to put significant effort into protecting the Colorado River. When it is hot out, river temperatures rise if there’s only a little water flowing.

Denver Water has agreed to keep water in the river during those periods and fill the lake during spring runoff. It will also draw water at different places in the river to minimize the impact to one area.

Gross Reservoir. Photo: Brent Gardner-Smith/Aspen Journalism

Thornton Water Project update

From The Loveland Reporter-Herald (Pamela Johnson):

Judge Juan Villasenor issued an order in 8th Judicial District Court on Sunday, granting the request of both No Pipe Dream and Save the Poudre to “intervene” in the lawsuit, essentially allowing both groups to back Larimer County’s decision to deny a permit for a section of water pipeline.

The ruling states that both groups have an interest in the decision of whether the pipeline can be built to carry water from the Poudre River to Thornton, but that “neither organization nor their members’ interests are entirely or adequately represented by the existing parties.”

[…]

The judge agreed in his ruling that those residents could be adversely affected by the pipeline and rejected Thornton’s argument that they should not have a say in the suit. He ruled that the group does have a legitimate interest in the case and is seeking the same result as the Larimer County — a court decision upholding the commissioners’ permit denial.

“Thornton contends — facetiously in the Court’s view — that the interests that the No Pipe seeks to protect aren’t germane to its purpose,” the ruling states, stressing that the residents’ interests could be harmed if the pipeline were built along either route.

“The outcome of this litigation could result in a loss of property through loss of the property itself, use, access or quiet enjoyment,” the ruling states, adding “Thus, No Pipe has an interest in the outcome of the litigation.”

[…]

The judge also allowed a second group, Save the Poudre, to join the lawsuit because, like No Pipe Dream, the nonprofit was involved in the process all along and is seeking the same result as Larimer County.

constitutionstateofcolorado
See Article 7.

A look at the history of Dillon Reservoir

Dillon townsite prior to construction of Dillon Reservoir via Denver Water

Here’s a report from The Summit Daily (Deepan Dutta). Click through and read the whole thing. Here’s an excerpt:

The lecture, titled “Dillon, Denver and the Dam,” took place in the old Historic Park Chapel behind the museum, where every pew was filled and the audience spilled out of the door. Mather, a former president of the Summit Historical Society who has written 20 books about Summit County’s rich history and has a doctorate in physical geography, spoke to the capacity crowd on why the reservoir was built and the numerous challenges it faced being built…

The reservoir’s need was first realized in 1907, when the city of Denver realized it would require a lot more water as it grew. In 1913, Denver Water started buying water rights around Summit County, seeing the area’s natural geography as ideal for a reservoir.

“This was a huge catchment area,” Mather said. “You had a confluence of three streams, the narrowing of the valley north of Dillon, you would have gravity flow through the tunnel across the Continental Divide, and all were very important.”

Unfortunately, many benefits that were found in geography were lost to the local geology. There were numerous challenges in trying to find a place to put the dam, and once it was found a whole lot of earth-moving had to be done to artificially strengthen the foundation and ensure water would not start leaking under the dam.

Before constructing the dam itself, a core trench was dug 90 feet deep under the entire length of where the dam now stands, down to the bedrock. Another trench was dug into the bedrock itself, and then giant holes were dug into that trench 300 feet deep and filled with concrete. Suffice to say, the dam built on top of that foundation is well reinforced.

When the dam was finally completed in 1963, it stood 231 feet tall, 5,888 feet long and over 580 feet wide. Twelve million tons of fill was used to build the dam, with most coming from borrow pits in the reservoir area.

Aside from the dam, constructing the reservoir itself was a herculean endeavor itself. Given that the entire purpose of the reservoir is to impound water for use elsewhere, the reservoir needed to be lined and segregated from the ground [water].

That’s why a steel liner was installed to ensure the water stayed in the reservoir and didn’t get contaminated. The liner – a quarter-inch thick, highly polished steel – was pieced together at the bottom of what is now the reservoir in 30-foot long pieces.

There’s also the matter of managing overflow. That job goes to a morning glory spillway, which is basically a giant cement funnel at the dam’s maximum capacity height of 9,017 feet. All overflows fall into this spillway, which features fins at the top to prevent a whirlpool at the top, which would create air bubbles that can deteriorate the spillway’s cement.

Overflow water runs straight down the gullet of the spillway, which is 15 feet wide at its narrowest part, before turning 90 degrees and running into the Blue River through a 15-foot wide fixed-wing gate, which can be opened and closed to regulate water flow into the Lower Blue River.

Denver Water employees Rick Geise and Nate Hurlbut assisted in setting the plug, which helps prevent chunks of ice and snow from falling into the spillway. Photo credit: Denver Water

When fall comes and the reservoir is lowered, the spillway is no longer in use. Mather explained that since cold water sinks, the spillway can get iced up inside, damaging the concrete. To prevent this, Denver Water uses a crane to lift a giant “plug” — a 6-ton steel disc — and lower it into the spillway, preventing ice and debris build-up.

Mather described another key component of the entire reservoir system, the Roberts Tunnel. The 23-mile long tunnel, which when built was the second largest in the world, takes water from the reservoir in the West through a 10-foot wide pipe across the Continental Divide and down 174 feet of elevation to the eastern portal in Grant.

Mather said the construction of the tunnel began one month to the day before she was born, on September 17, 1942. Construction of the tunnel officially ended two months to the day after Mather graduated from college, when the eastern portal opened 22 years later, on July 17, 1964.

@DenverWater hires contractor for Gross Reservoir Expansion Project

The Gross Reservoir Expansion Project will add 77,000 total acre feet — 72,000 for Denver Water use and 5,000 for an environmental pool that provides additional water for South Boulder Creek during low-flow periods — nearly tripling reservoir capacity.

From Denver Water:

Denver Water’s five-member Board of Water Commissioners on Wednesday approved a two-year, $4.5 million contract with Kiewit Barnard, a Joint Venture, for planning and pre-construction work during the final design phase of the $464 million Gross Reservoir Expansion Project.

If the team’s performance during the planning and pre-construction phase meets Denver Water’s expectations, a separate contract to build the dam may be signed between Denver Water and Kiewit Barnard.

“This is a major milestone in our 16-year effort to expand Gross Reservoir, as its original designers intended decades ago, to ensure a more reliable water supply in a future marked by greater uncertainty in weather patterns,” said Denver Water CEO/Manager Jim Lochhead.

Denver Water, the state’s largest water utility, serves 1.4 million people in Denver and surrounding suburbs.

Gross Dam enlargement concept graphic via Denver Water

The Gross Reservoir Expansion Project will raise the height of the existing dam, completed in 1954, by 131 feet, allowing the reservoir to nearly triple in size. When complete, the reservoir will be capable of holding about 119,000 acre-feet of water to provide greater system balance and resiliency.

The selection process for a construction manager/general contractor for the project began in August 2018 with information meetings, followed by a formal Request for Qualifications in October 2018. Three teams responded to the request and underwent extensive evaluations and interviews by a selection team that included experts from Denver Water, the project’s design engineer and subject matter experts.

The selection team focused on a value-based competitive process that examined each team’s qualifications, project approach, technical approach and cost.

“Kiewit Barnard met Denver Water’s high bar for doing a project that’s important not only to the 1.4 million people who rely on us for their drinking water, but also to the people who live around the reservoir,” said Jeff Martin, Denver Water’s program manager for the expansion project.

“We were impressed by the team’s experience with roller-compacted concrete dam construction, innovative approach and commitment to safe and responsible building practices,” Martin said.

The project calls for adding 900,000 cubic feet of concrete to the existing structure and building the first roller-compacted, concrete, arch dam in the United States. When complete, the Gross Dam will be the tallest in Colorado and the tallest roller-compacted concrete dam in the U.S.

“Kiewit Barnard, a Joint Venture, is very pleased to have been selected to work on this important project to support water demand for the greater Denver area,” said Jamie Wisenbaker, senior vice president of Kiewit Infrastructure Co., and an executive sponsor of the project. “We believe the team’s collective infrastructure experience in dam and reservoir construction and engineering will be a huge asset and look forward to safely delivering a high-quality project on time for Denver Water and the region.”

Kiewit is one of North America’s largest construction and engineering organizations with extensive heavy-civil experience in water/wastewater construction, including serving as lead contractor on the Oroville Spillways Emergency Recovery project in California. Kiewit is the No. 1 contractor for dams and reservoirs in the United States according to Engineering News-Record. The company also has strong roots and experience in Denver and across Colorado, including having constructed the Interstate 25 T-REX Expansion project, the U.S. 34 Big Thompson Canyon emergency repair project and the I-225 Light Rail Line project. The company also is building Denver Water’s new Northwater Treatment Plant.

Barnard Construction Co. Inc. brings a long track record of safety and quality on infrastructure projects in the U.S., including construction on more than 80 dams, reservoirs and dikes over the last four decades. The company’s work in this area includes new construction, raising dams and conducting emergency repairs. In 2019, Barnard was honored as a “Global Best Project” award winner by Engineering News-Record in the dam/environment category for the Muskrat Falls North and South Dams project located in Muskrat Falls, Newfoundland and Labrador, Canada.

The Gross Reservoir Expansion Project is awaiting a final federal government approval from the Federal Energy Regulatory Commission. Provided the remaining federal approvals come by the end of this year, the project is slated to be complete in 2025.

When finished, the expanded reservoir and associated mitigation projects will create what the Colorado Department of Public Health and Environment has described as a net environmental benefit to state water quality by generating a wide range of environmental improvements to streams, river flows and aquatic habitats.

Moffat Collection System Project update: “Our problem is rooted in demand and resiliency” — Jeff Martin

Gross Reservoir , in Boulder County, holds water diverted from the headwaters of the Colorado River on the West Slope. The reservoir is part of Denver Water’s storage system. Photo: Brent Gardner-Smith/Aspen Journalism

From The Colorado Sun (Amanda K. Clark):

Raising the 55-year-old dam near Boulder is essential to keep a stable water supply in a changing climate, utility says. Residents insist conservation could be just as effective.

Denver Water — Colorado’s largest and oldest utility company — in July 2017 received one of the final permits needed to raise Gross Reservoir Dam by 131 feet to increase water storage capacity by 77,000 acre-feet, or an additional 25 billion gallons of Western Slope water…

The expansion, in the works for more than a decade, is part of the company’s long-term plan to help meet increasing water demands along the Front Range and buffer customers from future water-supply variability due to climate change…

Denver Water has been met with sustained opposition from Boulder County residents and a handful of environmental groups who say the utility can address its water needs through expanded water conservation efforts on the Front Range.

But with Colorado’s population growth showing no signs of slowing, water conservation may be inadequate to address projected shortages in the coming decades.

Other concerns raised by opponents include sustained disruption to surrounding residents, increased traffic, health concerns and environmental impacts to fish and wildlife.

Gross Reservoir is filled primarily from snowmelt that flows from the Fraser River, a tributary of the Colorado River. The water is transported underground from west of the Continental Divide to the east by a pipeline called the Moffat Water Tunnel.

The controversy over the Gross Reservoir expansion, estimated to cost $464 million, echoes an all-too-familiar story: a highly contentious discussion of tradeoffs that has rippled across the Western United States for decades.

As cities and states across the West grapple with swelling population alongside diminishing water supplies as a result of climate change, water-resource agencies such as Denver Water are faced with the delicate task of balancing the health of ecosystems with municipal, agricultural and recreational needs…

Jeff Martin, Denver Water’s project manager for the expansion project, doesn’t skirt around the controversy. He recognizes that the project is going to cause disruption and says that Denver Water has worked with the residents to find ways to minimize the project’s impact.

“This has been a process,” Martin said. “We started in 2004, it took 13 years to move through the environmental assessment and permitting process. And we’ve made a lot of changes and adjustments to our plans since the beginning.”

“No single solution is out there,” he said. “Our problem is rooted in demand and resiliency, and what I mean by resilience is that we have to make sure we have the water when we need it, and where.”

[…]

For Patty Limerick, director of the CU Boulder’s Center for the American West and former Colorado Historian, you can’t talk about water issues on the Front Range without first looking back in time.

When early white explorers arrived here, they deemed the Front Range unfit for settlement due to lack of water. Today, 1.4 million Denver residents have access to clean drinking water due in large part to Denver Water’s enormous infrastructure web that diverts water from the South Platte, Blue, Williams Fork and Fraser river watersheds to be stored in a network of reservoirs spread over eight counties, including Dillon, Strontia Springs and Cheesman.

“One thing that I find fascinating, and is important to talk about, is the incredible amount of engineering that had to occur to make any of this possible in the first place,” Limerick said.

“We, as a society, have to recognize the improbable comfort that was made possible by a taken-for-granted, but truly astonishing, water infrastructure that was put in place a hundred years ago.”

[…]

“The year 2018 was very similar to what we would expect to see under a climate change regime. And that was a very intense but short-term drought,” said Taryn Finnessey, senior climate change specialist with the Colorado Water Conservation Board.

“We saw some reservoirs in the state declined by 50 percent in a three- to four-month period. So that obviously could not be sustained multiple years in a row,” she said. “Water providers are increasingly integrating climate change models into their water supply projections. They know that what we’ve seen in the past might not fully represent what we might see in the future. Denver Water is one of the more advanced utilities when it comes to this.”

Finnessey says it’s not just about how much precipitation falls from year to year. It also has a lot to do with increasing temperatures, contributing to the long-term drying out of the West, a phenomenon scientists are referring to as aridification. As temperatures rise, more moisture is sucked up by the atmosphere through evapotranspiration, leaving less viable water for humans-use in the system.

“We are planning for infrastructure that will be built in the next 20 years, that is supposed to last for the following 100 years,” said Reagan Waskom, director of Colorado State University’s Colorado Water Institute. “Our world is changing significantly faster than that. And not in a linear way. How do we adapt to that?

“Water managers have to plan for extremes,” he added. “A year like this year is an argument for reservoirs. Even with climate change, you’re still gonna have some good years. And we need to be able to capture it and save it for the bad years, whether that’s in underground aquifers or in reservoirs.”

Denver Water’s collection system via the USACE EIS