Phasing out old infrastructure creates opportunities for Coloradans to envision futuristic ways of moving, managing and treating water
In 1937, teams of men swung their pickaxes into the Colorado sod just north of Golden to build Ralston Dam and bury veins of pipe that would carry water south toward the fledgling city of Denver. That growing community had just constructed its City and County Building in 1932, and, by 1934, boasted a symphony orchestra. Civilization was sprouting, and with the Ralston Creek project, the Denver Board of Water Commissioners apparently wanted to make a grand contribution to the city’s future. Maybe they sensed that they, like the ancient Romans, would be forever judged by the quality of their works. They built Ralston Dam and its network of valves and pipes to serve many generations of Coloradans—and, 80 years later, they’re still in service.
These days, suburbanites steer air-conditioned SUVs between the shopping centers and drive-throughs that have replaced the farmlands adjacent to the city center where workers buried pipe throughout the 1930s. And that infrastructure is finally showing its age. Cracking pipes are leaking water, and the utility is forecasting even bigger breakdowns ahead. The Moffat Treatment Plant, which was a cutting-edge facility when it was originally built, east of Ralston Dam, is now hemmed in by nearby housing and, with no room to expand, can’t keep pace with modern expectations.
Today’s residents and water providers grapple with issues that Denver’s settlers never could have envisioned. Climate change has intensified weather events and increased the frequency and severity of wildfires and flash floods—which can dramatically impact watersheds and the communities that depend on them. (In September 2013, record rainfall turned Ralston Creek into a firehose that eroded infill channels and destroyed water monitoring equipment at Ralston Reservoir.) New contaminants, such as pharmaceuticals and perfluorinated compounds, are infiltrating water supplies. And with human populations growing in Colorado and across the West—the 2019 Technical Update to the Colorado Water Plan projects that the state’s population could grow from around 5.4 million people in 2015 to between 7.6 and 9.3 million by 2050—we’ve become savvier about the importance of conserving water and other natural resources that seemed inexhaustible just 100 years ago. We’ve also witnessed development’s negative environmental consequences, and are prioritizing less impactful systems.
To address 21st-century concerns, Denver Water initiated a $600 million overhaul of its North System, which includes Ralston Reservoir and the Moffat Treatment Plant, which is Denver’s oldest. That plant will be repurposed into a water distribution center where water will be stored and eventually sent out to customers, while a new Northwater Treatment Plant will feature sustainable, energy-efficient systems with extra-deep filter beds capable of extracting today’s contaminants—all while producing some 75 million gallons of treated water daily. The project’s first phase began in 2017, when new pipeline was laid to replace the old. Completion is scheduled for 2024.
The North System Renewal ranks as Colorado’s most ambitious water infrastructure development at present, in price and scope, according to Denver Water, but it’s far from the only project to attempt next-gen solutions. All across the state, water providers, developers, farmers and consultants are taking visionary approaches to maintaining yesterday’s water infrastructure and upgrading it for tomorrow. Some solutions emphasize efficiency, while others prioritize human and environmental health. What they all have in common—from the smallest pilot project to the largest, $600-million overhaul—is multi-dimensionality. Water infrastructure must now serve many masters.
Harnessing Data’s Power
The City of Westminster is a 113,000-resident suburb located 8 miles north of Denver. Ten years ago, its water utility handled infrastructure upgrades and maintenance requests as most municipalities do: It doled out money as needs arose. That meant Westminster was constantly reacting to past problems rather than steering its future.
“As a utility, we do not have a savings account,” explains Julie Koehler, Westminster’s utility engineering manager. Instead, ratepayers contribute through their monthly bills, based on their usage and meter size, to the city’s enterprise fund for infrastructure needs—but system crises always seemed to deplete that fund, leaving nothing for future planning. So in 2010, Westminster inventoried its water infrastructure systems and created a database that now dictates what rates must be to accomplish the city’s present and future goals. The database also determines when money will be spent, and on what.
“What this database allows us to do is very strategically plan for the repair or replacement of different parts in the utility, because we know what year each part was installed, and what year the industry deems that part to be at the end of its life,” explains Koehler. That database also helps the City of Westminster plan for future water quality regulations or new processes like monitoring for specific contaminants that could be coming down the pike, Koehler says.
That kind of data-tracking system may seem simple, but it has effectively revolutionized Westminster’s ability to maintain, upgrade, and build water infrastructure. “Having the data, there’s no speculation with cost forecasts,” Koehler says. “We know that in 10 years, say, we’ll need a million dollars, and we’ll know exactly for what.” Thus Westminster uses the database to plan its rates and fees.
That transparency has made it popular with the city’s engineers. “There’s no longer any infighting between the water, pipeline and wastewater factions, who used to argue over who was taking all the money,” explains Koehler. “Now, everyone’s needs are tracked, so it’s clear where the money’s going.” Of course, no ratepayer wants her bills to increase, and some Westminster residents objected to rate hikes.
However, says Koehler, “Knowing what we need and how to plan for it has allowed us to be more forward-thinking.” Westminster is currently in the process-selection phase of planning for a new water treatment plant. Patching together the old facility wasn’t a safe or reliable option: Its concrete, pumps, and chemical feed systems are all failing, says Koehler. Besides, she adds, the new facility will address new water quality issues that people couldn’t have imagined in the 1960s, when the existing plant was built. Explosions of certain plant and animal populations, such as zebra mussels, milfoil and algae, can compromise the quality of Westminster’s water supply, and catastrophic wildfires and floods now present periods of impacted water. The new water treatment facility will be able to handle such surges without spiking residents’ costs.
Such plans do require the utility to present constituents with tough financial forecasts. “We know that in 2023, we’re going to have to issue $125 million in debt in order to start construction of the first phase,” says Koehler. “That’s not a comfortable thing to tell people, but the data lets us say it with confidence: This is what we need.”
Battling Next-Gen Pollutants
Many of today’s contaminants weren’t addressed by decades-old infrastructure for water or wastewater. But these days, both are increasingly impacted by a growing assortment of contaminants such as chemicals, pharmaceuticals, plastics, heavy metals, and more. In some places, changing regulations to cope with emerging water quality concerns have rendered old infrastructure outdated before the end of its useful life so municipalities are investigating new infrastructure to suit.
In 2016, the community of Widefield, located southeast of Colorado Springs, along with neighboring towns of Fountain and Security, detected per- and polyfluoroalykl substances (PFAS), previously referred to as perfluorochemicals (PFCs), in its groundwater at levels that were above the U.S. Environmental Protection Agency’s new 2016 health advisory levels. The contamination has been traced to firefighting chemicals used to quench fuel fires at military airports and has been linked to severe health challenges including cancers, liver and kidney damage, and more. Widefield’s existing water treatment system, though still functional, wasn’t equipped to remove or mitigate PFAS, so it was forced to upgrade.
Widefield Water and Sanitation District hired JDS-Hydro to develop a pilot program and construct a new treatment system. Carbon filtration, the most commonly used approach to PFAS treatment, wasn’t a good option because Widefield’s aquifer contains nitrates that can saturate carbon filters and cause “nitrate rolloffs” that result in problematic nutrient spikes. JDS recommended an ion exchange system that easily handles high water volumes while requiring cheaper, less frequent future maintenance. They fitted an ion exchange system in a corner of Widefield’s existing water treatment plant.
“Using ion exchange to treat PFC has been a game-changer,” says Mark Valentine, director of JDS-Hydro. “It’s more costly up front, so to get public acceptance for more innovative technologies, you have to help people understand why that up-front cost may actually pay off over the long term,” he says. With a price tag of $2.5 million, Widefield drew from its cash reserves to pay for the new system, which meant that some planned upgrades to the city’s water and wastewater system had to be postponed, but its immediate needs were met.
Nearby Security also tapped into its reserves to address the unexpected PFAS concerns, spending 40 percent of those funds to construct pipelines for purchased water from Colorado Springs Utilities. That effort diverted cash from its intended use: replacing aging underground pipe. Without those reserves, says Roy Heald, general manager of Security Water and Sanitation District, Security wouldn’t have had the flexibility to adapt to the unforeseen circumstances. “When it comes to planning and upgrading infrastructure, we still take the long view,” Heald says. “But I can’t forecast the next contaminant. It’s like the coronavirus; you just have to deal with it. And it’s hard to be nimble without money.” Thanks to that banked cash, Security and Widefield were able to quickly meet the contaminant challenge by adapting old infrastructure and building new elements to uniquely address their needs.
Much of Colorado’s aging infrastructure wouldn’t meet today’s standards for sustainable materials and construction. Some older parts were made with materials such as volatile organic compounds (VOCs) that, we now know, may harm human and environmental health. And many foundational systems were built with a “bigger is better” mindset, says Sarah Dominick, who worked at Denver Water for 12 years before joining Hazen and Sawyer as a consultant where she now helps utilities plan for a range of issues, including aging infrastructure. The growing cities of yesteryear imagined that future residents would always demand more water, not less. Yet today’s water-saving toilets and appliances have actually decreased households’ usage. “Some parts of our infrastructure are oversized, because they were designed for peak flows that we never hit,” says Dominick.
Instead, she explains, forecasting future needs has more to do with resiliency than oversized capacity. The Envision Framework, out of the Institute for Sustainable Infrastructure, outlines best practices for sustainable water infrastructure planning and construction and can help water providers replace aging parts and systems with updates that add resiliency, Dominick says. “Climate change, future regulation, and intense drought are just some of the future issues that utilities will confront,” Dominick says. While Envision is most effective when used in the earliest phases of project development, it can also be used when infrastructure needs to be updated. “Extending the life of existing assets is often more sustainable than building new assets,” Dominick explains. Thus Envision’s credentialing process, ENV SP, trains water professionals in approaches that emphasize resiliency and sustainability from planning to maintenance. About 150 ENV SP certifications have been awarded to professionals working in Colorado.
Westminster’s public works department, which has encouraged its staff to pursue ENV SP certification, now boasts 15 professionals with ENV SP certification, and 17 more are undergoing training. That knowledge has prompted the department to scrutinize the materials used in water plant processes and parts to ensure they are safe during their useful lifetime and after removal and disposal. “We know this now about asbestos, for example,” says Koehler. Elements of water infrastructure systems “need to be just as safe coming out as they were in service,” she explains.
Fortunately, prices for sustainable parts, such as those made without VOCs, are declining as demand for non-toxic water infrastructure products has increased, Koehler says. “It helps us as an industry to think about the future of the products that we’re putting in today,” says Koehler.
Dominick also recommends that managers use phased construction to replace or upgrade aging infrastructure, allowing them more flexibility when responding to future needs—which may be unforeseen. “If you install a giant plant with one treatment technology, you may not be prepared to address new contaminants,” she explains. “But if you right-size the infrastructure, it’s more sustainable because you’re not building too big.” Designing a facility that can be easily expanded allows additional phases to be built when the need arises and if the need never arises the utility can save money. Denver Water’s Foothills Water Treatment Plant is a good example of this type of planning.
Dominick also sees a growing trend toward infrastructure rehabilitation rather than replacement. “It can be much easier and less impactful to line a pipe than to rip it out and install a new one,” she explains. Engineers are even getting savvier about designing plants that facilitate maintenance and updates. “That wasn’t necessarily top of mind many decades ago, so simple maintenance like changing the oil in a pump might’ve required removing the plant’s ceiling,” Dominick says, describing a fictitious example of the ways that old systems often handicapped ongoing care and repair. New designs are more likely to consider asset management. The Envision framework fosters an improvement in the resiliency of infrastructure by encouraging project decision makers to incorporate sustainable design elements that continue through the life cycle of the project.
Demands on Colorado’s water have only grown since managers installed the previous generations of water infrastructure. Then, infrastructure’s goal was to move water—not necessarily to ensure its purity or to stretch it as far, says Cynthia Koehler, executive director of WaterNow Alliance, which promotes sustainable water infrastructure. “We’ve added new priorities onto our water infrastructure.” That’s a heavy burden to place on any one water provider, so communities are increasingly looking not just to replace aging systems with more of the same, but to diversify their infrastructure and think more holistically about their systems—often to include distributed technologies.
Broadly speaking, distributed infrastructure considers all elements of a water system including green infrastructure, fixtures, sprinkler systems and lawns, and in some cases lets water users—not just providers—share in the process of collecting, moving, or treating water. The overarching draw, says Cynthia Koehler, is the flexibility and resiliency that distributed infrastructure can provide. When used alongside conventional systems, distributed systems can help communities achieve their growth and sanitation goals without committing to wildly expensive new plants. “We shouldn’t be defining the problem as, ‘How do we deal with aging infrastructure?’” she posits. “It’s ‘How do we address the problems that infrastructure is there to address?’” Distributed infrastructure creates a broader portfolio of solutions.
Graywater reuse, for example, can help communities keep their aging centralized systems in service for a longer period of time by lessening pressure on those systems. “Our reuse systems reduce the load [on municipal systems] by 20 to 25 percent,” says John Bell, chief commercial officer for Greyter Water Systems based in Ontario, Canada. “Implemented at scale, reuse could alleviate the need for towns to build new pipelines costing millions of dollars. And in remote communities, where developers have to build new wastewater treatment facilities, graywater reuse could let them build smaller plants,” he adds.
Greyter’s first Colorado project is a 40-home development in northeast Denver’s Stapleton neighborhood that will capture shower and bath water for reuse in homes’ toilets. Construction began in June 2020 and was funded, in part, by a grant from the Colorado Water Conservation Board.
Various technologies can treat “used” water to standards that are not quite as high as the expectations placed on drinking water—thus some Colorado water providers have converted wastewater streams to irrigation water for parks and golf courses. Most household systems focus on “graywater” from bathroom and laundry room sinks, washing machines, and shower drains into water for irrigation and other non-potable uses, such as flushing toilets. But in Colorado, regulations and consumer acceptance still lag behind the available technology. Only Castle Rock, Denver and Pitkin County have so far adopted a Colorado code known as Regulation 86, which guides how graywater can be recycled.
Yet even more than many Western states, Colorado stands to benefit from water reuse, says Bell. That’s because Colorado’s growth projections threaten to increase the load on conventional water infrastructure. “But if you can defer the load, you can potentially increase the building volume,” he explains.
Reuse isn’t the only distributed water efficiency measure at work in Colorado. “There are a lot of communities on Colorado’s Front Range that are just booming, but they’re thinking, ‘Where is my next gallon of water coming from?’ They can be looking at fairly expensive new infrastructure and fairly challenging political and financial burdens in terms of acquiring new water rights and building pipelines to far away sources of water,” Cynthia Koehler explains. Distributed systems like turf replacement programs and green stormwater infrastructure could help address those needs without the soaring costs of building new conventional plants and pipes.
“Conventional-built infrastructure has done us a lot of good over the years, and we are going to continue to use it for many more,” says Cynthia Koehler. But looking forward, she adds, Coloradans can expect to see more combined systems. By complementing conventional networks with distributed technologies, she says, “You are extending the life of conventional infrastructure, you’re lowering costs, and you’re serving the same function as those centralized solutions.”
Upgrading Irrigation Systems
Cities and residential developments aren’t the only sectors that are updating water infrastructure to meet the next wave of needs. Agricultural operations are also re-evaluating existing structures and developing ways to make them meet multiple needs and values. In revitalization projects, “multi-benefit” is the buzzword.
“New agriculture infrastructure is more efficient than the old open ditches and headgates, but that’s just one of its benefits,” explains Dave Kanzer, deputy chief engineer for the Glenwood Springs-based Colorado River District. Because upgraded systems can divert less water, more can remain in the stream, benefiting fish and wildlife, water quality, and recreational users.
Replacing open irrigation ditches with enclosed underground piping is a high priority for the Colorado River District. Many of the Western Slope’s ditch systems are 50-100 years old. Occasional failures can result in damage due to localized flooding, but breaches and breakdowns aren’t the only drawback to aging infrastructure. Loss of water due to old, inefficient systems means that operators may have to divert twice the quantity of water that crops actually require. Ditch-and-furrow irrigation is also labor-intensive. Farmers must battle weeds and algae with controlled burns and noxious chemicals. And, across much of western Colorado, irrigation ditches run through marine-deposited shales that inadvertently load groundwater and return flows with salt and selenium, before that water eventually enters the Colorado River, adversely affecting downstream users and wildlife. Advanced irrigation systems can minimize that leaching.
“New systems that integrate pressurized delivery systems with drip and sprinkler irrigation can improve water efficiency to 80-90 percent,” says Kanzer. The pressure that pushes water through pipe networks can also be harnessed to drive sprinklers and other irrigation devices, allowing farmers to save money by reducing their electric bills. For example, the Meaker Farm south of Montrose now exploits the pressurized pipe system rather than electricity to pump and deliver water to its big guns and center pivot irrigation.
The Lower Gunnison Project, for example, is a comprehensive series of improvements designed to boost agricultural water use efficiency and productivity while improving water quantity, quality and habitat to stabilize stressed populations of four federally listed endangered fish and three species of special concern. Using a portfolio of federal and state funding, the Lower Gunnison Project, managed by the Colorado River District, has been able to leverage about $50 million for projects throughout Delta and Montrose counties and has been able to expand U.S. Bureau of Reclamation Salinity Control Program funding in the Uncompahgre Valley. One of the largest irrigation water users within the Colorado River Basin in Colorado, the Uncompahgre Valley Water Users Association (UVWUA) has piped more than 150 miles of its vast irrigation network.
Agricultural operators in the Lower Gunnison Project area also benefit from the upgrades. UVWUA is replacing antiquated headgates with SCADA (system control and data acquisition) systems that give operators immediate feedback on the adjustments they make, so they know whether they are meeting their crop demands without waste and hitting their water efficiency targets. The Lower Gunnison Project has also helped build surge reservoirs in the project area along with accurate measurements and controls to provide irrigators with a consistent water supply to counteract the naturally occurring surges they previously faced.
And when agriculture’s infrastructure upgrades benefit more than just the landowner, organizations such as Trout Unlimited and The Nature Conservancy grow interested in sharing the cost.
For example, the Five Ditches Project on the Rio Grande River, between Alamosa and Del Norte in southern Colorado’s San Luis Valley, cost $2.8 million—but enjoyed financial support from such entities as the National Resource Conservation Service (NRCS) and the Colorado Water Conservation Board. Grantors are eager to fund projects that accomplish multiple goals, says Emma Reesor, executive director for the Rio Grande Headwaters Restoration Project that oversaw the Five Ditches effort. Many diversion dams were difficult to maintain, and replacing them with newer versions eased labor burdens on area ag operators. The updates also included fish ladders and riparian restructuring that benefit wildlife. And new headgates improved efficiency, allowing operators to divert less water. “Our first and foremost goal was to make sure the irrigators got their water,” says Reesor. “But the project also had significant additional benefits, and to get grant funding, it needs to be a multi-benefit project.”
Pleasing multiple stakeholders—from households to farms to recreational enterprises and environmentalists—wasn’t foremost on settlers’ minds as they constructed the state’s first water systems. But the builders of Ralston Dam and other foundational projects knew that Colorado’s future would include dramatic changes. Today’s water managers also face changing human populations, evolving contaminants—even alterations to the earth’s very climate. Even the most visionary water providers can’t anticipate or plan for every future need, but they can prioritize resilient infrastructure that can pivot to changing realities. Thus, the future of infrastructure might not be constructions that last, but ones that adapt.
Correction: An earlier version of this article, and the version printed in Headwaters magazine, incorrectly stated that the City of Westminster would have to issue $25 million in debt. Westminster will actually have to borrow more like $125 million.