Pitkin County will begin construction next week on the latest fix to a whitewater park on the Roaring Fork River in Basalt that some said was too dangerous during high water last summer, sources said Wednesday.
“The primary goal of the adjustment is to improve high-flow navigation from runoff,” said Quinn Donnelly, an engineer with River Restoration of Carbondale, which designed the park. “(High water) was creating big holes and people were flipping.”
Contractors next week will begin altering two man-made concrete wave structures in the riverbed to make them less difficult to navigate during high-water conditions, Donnelly said. Crews will move around boulders and create ramps to better flush water through the area and create a wave-train, he said.
“The goal of this winter’s work is to strike a better balance between the fun surfability of the waves and their high-water navigability,” Pitkin County Healthy Rivers and Streams Board Chairman Andre Wille said in a news release Wednesday. “The end result will be wave features that are easier for river runners to bypass at high flows.”
Despite repeated requests Wednesday for how much the project will cost and where the money will come from, a spokesperson for the Pitkin County Healthy Rivers and Streams Board declined to release it. The park was initially built for $770,000 with Healthy Rivers funds, though it’s not clear how much has been spent since then to tweak it.
This winter’s project will mark the second time the whitewater park has had to be re-engineered because of safety concerns.
Snowfall in Aspen is pacing well ahead of average this ski season thanks to a big opening blast in October and above-averages dumps in December.
The Aspen Water Treatment Plant recorded 84.70 inches of snowfall for October through December, according to the monthly weather reports. That is 28.45 inches or 51% above the average of 56.25 inches, according to the water department’s records.
Each month has been well above average at the plant, which is situated at 8,161 feet, slightly above downtown Aspen’s elevation. The cold-weather months started with a bang when 26.70 inches of snow fell in October. The average is 9.20 inches.
November was closer to typical conditions when 23.50 inches fell, the water department reported. The average snowfall for the month is 21.90 inches.
December kept the trend going with 34.50 inches of snowfall, well above the average of 25.15 inches.
None of the months came close to breaking a record for snowfall. The December record, for example, is 72 inches in 1983.
More snowfall than usual at the 8,100-foot level hasn’t translated into a significantly higher snowpack than average at higher elevations. The snowpack at the headwaters of the Roaring Fork River east of Aspen is at 107% of median as of Friday, according to the Natural Resources Conservation Service, a federal agency that has automated snow telemetry sites scattered around the Roaring Fork watershed.
The snowpack at the Independence Pass site was at 7.7 inches of snow water equivalent — the amount of water produced when the snow is melted. Last year on the same date it was 7 inches.
The snowpack at the headwaters of the Crystal River Valley was 97% at Schofield Pass and 97% at McClure Pass as of Friday.
The snowpack at the headwaters of the Fryingpan River Valley was 147% at Ivanhoe Lake and 131% at Kiln, according to the snow telemetry sites.
Approaching Labor Day weekend of 1961, many Aspenites who had plans to go camping or enjoy outdoor concerts watched in trepidation as monsoon rains didn’t let up for two days. Then, that Friday night, the damp chill turned rain to snow — large, wet snowflakes fell overnight and for the next two days, thoroughly coating the green, late-summer landscape. Tree limbs bent and snapped, the music tent started to rip under the weight of the snow, motorists were stranded when Independence Pass closed and the power went out in the city for two days.
“It was a hell of a mess,” said lifelong Aspenite Jim Markalunas.
The mayor called Markalunas and asked him to reboot the defunct hydroelectric plant he had previously run while the regional electric utility struggled to restore the downed lines.
He managed to restore power to Aspen, and by the time residents woke up to a cold, sunny Labor Day morning, 27 inches of snow had fallen in town, a record that still stands, according to Markalunas, author of “An Aspen Weather Guide” and “Aspen Memories.”
Now 89, Markalunas also has tales of being surrounded by massive snowbanks as a 6-year-old in the 1930s and worrying about roofs collapsing from the heavy-snow years of the 1980s.
“Big snow years are oh-be-joyful for the (Aspen Skiing Company) and skiers but made for a lot of hard work for people maintaining the streets and intakes and such,” he recalled.
Markalunas remembers lean years, too, most notably the winter of 1976-77. That ski season didn’t start until January and recorded just 86 inches of snow all winter. It also spurred massive investments in technologies to battle drought impacts, such as snowmaking and cloud-seeding.
Markalunas likes to say that Aspen’s weather is “consistently inconsistent.” But he started noticing a difference in patterns in the 1980s — in particular, less-frequent below-zero temperatures.
“The trend is we just don’t have the super-cold weather we used to have,” he said, pointing to weather data he has compiled from water department records showing that Aspen has hit a low of less than minus 20 just once since 1997.
“It seems as though the weather pendulum swings more extremely than in years of old,” Markalunas writes in “An Aspen Weather Guide.” “Storms are more violent but less frequent. The weather appears to be more volatile than in past years. … Unless we act to decrease carbon dioxide emissions, ski racks on SUVs might become useless accessories here.”
Markalunas’ observations are supported by other data, analyses and studies that paint a picture of a changing local climate. Pitkin County is warming, the number of frost-free days is increasing and snowpack is declining — all of which have myriad impacts on recreation, the ecosystem, wildlife, streamflow, water availability, droughts and wildfires. One of the most notable impacts is on the underpinning of modern Aspen’s economy: snow and skiing.
Officials at Aspen Skiing Company, or SkiCo, have been aware of changing temperatures and snowfall for some time. Like others, the biggest change that Rich Burkley, SkiCo’s senior vice president of strategy and business development, has seen in his 30-year career is more variability.
“It’s a feast of riches or famine, and you have to deal with that,” he said.
Pitkin County’s average temperature has been rising at a rate of 0.4 degrees per decade since 1950, according to the National Oceanic and Atmospheric Administration. In 2018, the average temperature throughout the year in Pitkin County was 39.5 degrees — 2.9 degrees warmer than the mean temperature during the baseline period of 1950-75.
More-dramatic changes are happening in the cold-season months. Temperatures are rising almost half a degree per decade between November and April, compared with about one-quarter of a degree the other half of the year.
March is by far the fastest-warming month, heating up at a rate of 1 degree per decade since the 1950s. The average temperature of 34.4 degrees in March 2017, when Aspen hosted the World Cup ski racing finals, was a record 9.4 degrees higher than the 1950-75 baseline temperature.
The race venue on the lower half of the mountain lost several inches of snow surface per day, Burkley said. The only reason there was enough snow to race on was extra early-season snowmaking that at the time was considered excessive.
Markalunas’ theory of fewer really cold days shows in this data as well. Average annual low temperatures have risen in Pitkin County and appear to be accelerating — average minimum temperatures were more than 5 degrees higher than the baseline during three of the past five winters.
“Even since 1980, there has been a pretty sharp annual average temperature increase over time,” said Elise Osenga, research and education coordinator for the nonprofit Aspen Global Change Institute, or AGCI. “Even just a couple degrees difference is a notable difference in annual average temperatures — especially if you are a seasonal-sensitive plant or animal.”
A 2014 report by AGCI notes that rising low temperatures, particularly in early winter, can affect the ability to make snow on the ski mountains, an activity typically limited to November and December. This hasn’t impacted SkiCo much yet, according to Burkley. Snowmaking now is about twice as efficient as it was two decades ago, thanks to automation and improved technology.
SkiCo also has plans to expand snowmaking to the top of Aspen Mountain next season, which Burkley said will be key to Thanksgiving openings as the upper part of the mountain often doesn’t have enough natural snow in November.
Zooming out, a recent Washington Post feature found that Pitkin County and much of the Colorado Rockies are warming faster than other places. Pitkin County’s average temperatures have risen 2.34 degrees since 1895, at the height of the Industrial Revolution; the average across the United States is 1.8 degrees. In fact, western Colorado and eastern Utah comprise a large “hot spot” that warns of greater climate shifts to come.
Freezing? Not so much
One critical trend related to rising temperatures — in particular, rising low temperatures — is an increase in the number of frost-free days, which AGCI counts as consecutive days of above-freezing temperatures from the last freeze of spring to the first time it dips below 32 degrees after that. Like temperature, the number of frost-free days has risen sharply in recent decades.
Since the 1980s, there’s now an additional month each year without freezing temperatures in Aspen, according to AGCI’s analysis. The actual number of days above freezing varies widely from year to year, but there is a clear upward trajectory, as seen in the Forest Health Index, which is produced by the Aspen Center for Environmental Studies with help from AGCI.
Higher temperatures mean less snow
Changes are, of course, also being felt beyond ski-area boundaries. In the summer of 1994, big-mountain skier Chris Davenport first skied 14,092-foot Snowmass Mountain, named for the massive snowfield that historically stretched across a wide bowl below its summit.
“In the next decade or so, it seemed like that permanent summer snow was getting smaller and smaller, until one summer in the mid-2000s, it was totally gone,” said Davenport. “It’s a direct effect of warming — even if it’s a few degrees, that snowfield couldn’t hang on.”
Winter snow might still linger into the summer months on Snowmass, Davenport said, but most years, the formerly year-round snowfield is gone by mid-July.
The waning snowfield on Snowmass Mountain is representative of a larger trend. Summer snow covering the Northern Hemisphere receded from 10.28 million square miles at its peak in 1979 to a low of 3.69 million miles in 2013, according to Climate Central’s website WXshift.com. Not only does that impact water supplies, but less snow cover means more sunlight absorbed by Earth, driving a feedback loop of further temperature increases.
Snowfall has also decreased in many parts of the United States, according to the Environmental Protection Agency, although no significant trends in precipitation have been found in the Aspen area or Colorado in general. Some climate models predict more precipitation in the future, but rising temperatures could mean that precipitation comes more often as rain rather than snow.
In Pitkin County, as in the American West and other mountain drainages around the world, snowpack is arguably the most consequential climate-change indicator. Mountain snowpack not only determines availability of snow for recreation but also how much water will be available for all manner of natural and human uses. In Colorado, including the Roaring Fork River valley, snowpack — usually measured by the amount of water in the snow, known as snow water equivalent, or SWE — is generally variable and can range widely from year to year. But this, too, has become more extreme in recent years.
“We’ve observed these huge year-to-year shifts,” said Karl Wetlaufer, a hydrologist with the U.S. Department of Agriculture Colorado Snow Survey, which collects and manages snowpack data. “So that does feel like a trend: Over the last 15 years, things seem to be much more erratic, with more extreme years on both high and low ends.”
The scientific community considers the April 1 snowpack the peak of the water year. Only once since 2010 has the Roaring Fork basin’s snowpack on April 1 been measured between 85% and 115% of normal, said Wetlaufer. That range was more common in earlier periods.
The last two winters feature some of the wildest snowpack swings — and the most extreme weather events. From October 2017 to September 2018, snowpack peaked at 72% of normal; the following snow season, it peaked at 144%.
The low-snow season resulted in such tinder-dry conditions that the Lake Christine fire, the most threatening fire in recent valley history, burned for months in the summer of 2018. That was followed by a winter capped off with an unprecedented avalanche cycle, the result of a steady buildup of the snowpack on a weak base layer, ultimately unleashed by a massive storm cycle that was fueled by warm atmospheric rivers from the Pacific Ocean.
Besides more variability, some recent scientific analyses, including this map produced by the EPA and AGCI’s 2014 report, have found that Colorado’s snowpack is decreasing. A study published by Peter Goble and Nolan Doesken of Colorado State University’s Colorado Climate Center found that central Colorado’s snowpack is diminishing by an average of .49 inches of SWE per decade, which was the most of the four regions studied. This calculation includes measurements taken at a station near Independence Pass.
A half-inch of SWE can equate to 7.5 to 10 inches of snowfall, Goble said, which over 100 years could mean 75 to 100 fewer inches of snow — about one-third of the roughly 300 inches that fall on average on the Aspen Snowmass slopes.
“Considering that loss may accelerate, those numbers look a little threatening to the local lifestyle,” said Goble.
Recent research also accounts for factors such as dust on snow, likely to be more frequent in the future given the increasing aridity of areas west of Colorado and more human disruption of those areas. Dust on snow, similar to rain on snow, melts the snowpack more quickly.
Scientists agree that the main factor contributing to a declining snowpack is not less snowfall but warmer temperatures due to increased greenhouse-gas emissions. And because temperatures are expected to continue to rise — the amount depends on how much emissions are curbed — snowpack around Aspen and elsewhere will continue to decline.
Still, Goble is hopeful.
“When you look at the projections and how winters might change, it’s not a totally hopeless situation,” he said. “We still have control over our future. If this is a problem humans take seriously and we see a lot of action on a large scale over the next couple decades, it will make the outlook for the back half of the century a lot brighter than if it was business as usual.”
AGCI’s 2006 report for the city of Aspen, on the other hand, painted a dire scenario for future skiers (as well as downstream water users) with continued warming, including the potential for shorter ski seasons and substantially reduced snow cover.
Aspen Mountain will still be skiable in 2030 under all emissions scenarios, the report concluded, but “by 2100 the base area of Aspen Mountain has essentially lost a skiable snowpack, with the exception of the lowest greenhouse-gas concentrations.”
In all future emissions scenarios, the AGCI report found that Aspen Mountain’s base snowpack will start to accumulate later in the fall and melt earlier in the spring due to warming temperatures. Snow depths at all elevations are projected to be reduced throughout the season. In the worst-case scenario, the ski season will be 10 weeks shorter by 2100 and “snow depth goes to near zero for the entire lower two-thirds of the mountain.” That’s everything below the base of the Ajax Express chair.
“Under these scenarios, some of our seasons are shortened and our terrain could be reduced,” Burkley said. “We would be in download situations more frequently. We would build and concentrate snowmaking at higher elevations. We might have more hike-to or hike-out terrain. We would build lifts to access areas that have more consistent snowpack.”
Burkley said with existing infrastructure, SkiCo can offer lift-served, high-elevation skiing on three mountains. The proposed 180-acre Pandora expansion on top of Aspen Mountain also would expand into terrain that “will probably have the best snow in the future.”
Even as SkiCo relies more on snowmaking, Burkley acknowledges minimum streamflow requirements could be an additional challenge. There could be a time when natural snowpack declines to the point that there won’t be enough water in local streams to make all the snow it needs, in which case the company might have to decide to shut down one or more of its four mountains and focus efforts on what remains open.
SkiCo is also increasing its focus on summer operations, including Snowmass Bike Park. For now, this helps ensure a return on expensive infrastructure; later, it could help make up for shorter winters.
Ironically, the Aspen Snowmass ski areas could actually benefit in the short term from climate change. They’re situated at higher elevations with colder temperatures than many other resorts, especially those outside of Colorado, and could see increased visitation as lower-elevation ski areas become less viable.
Clearly, Aspen isn’t the only ski resort facing an existential crisis. Ski areas across the country are recognizing the challenges that climate change poses to their viability, and that’s provoking a shift in industry thinking.
“In recent memory, climate was an uncomfortable conversation. Resorts said it was politicized science,” said big-mountain skier Davenport, who is now a climate activist and board member of the advocacy group Protect Our Winters, or POW. “Now everyone’s on board.”
The scale of action is bigger than resorts switching to renewable energy or lobbying for climate-friendly policies in Washington, D.C., as SkiCo has been doing for years. Three of the largest industry groups — Outdoor Industry Association, Snowsports Industries America and National Ski Areas Association — recently formed the Outdoor Business Climate Partnership to provide leadership and inspire action on climate change. Using POW’s playbook, SIA launched United by Winter, a climate-advocacy platform for its members. And POW is now on the radar of elected officials in every state where the outdoor industry has a presence.
“It used to be inconvenient for outdoor companies to talk about climate change, but now the opposite is true: If you’re not having that conversation, consumers aren’t buying from you,” Davenport said. “Look how we’ve changed the conversation.”
Untreated, polluted water flowing into the Roaring Fork River in the heart of Aspen and failing underground storm water infrastructure has the municipal government looking for new revenue streams to put toward an underfunded clean river program.
The city has made progress with capturing and filtering runoff before it hits the Roaring Fork from the Aspen Mountain basin on the south side of the river, with catch basins and wetlands near the Rio Grande park and trail.
But on the north side of the river, where east end neighborhoods and homes on Red Mountain are located, untreated storm water runoff goes directly into the Roaring Fork.
That is one likely cause of why the state has put the Roaring Fork on its watch list of impaired waterways, said April Long, the city’s clean river program manager.
Long has been charged with finding new revenue sources to fund the storm water department and clean river program in which almost $19 million in capital projects have been identified.
Ramping up the program is a priority that Aspen City Council zeroed in on earlier this year as it learned it is woefully underfunded…
The main funding source for the clean river program now is a property tax passed by voters in 2007 and put in place in 2008. It generates about $1.2 million annually.
But with underground corrugated metal pipes that are more than 40 years old and are rusting out, replacing just a third of the infrastructure is anticipated to cost $4 million, according to Long…
City Engineer Trish Aragon noted it costs more to replace pipes in emergency situations, and getting out in front of it is a better use of taxpayer money…
The department has identified just under two dozen projects that would create a more robust clean river program and address some of the state’s concerns.
One of them that will get some preliminary attention next year is designing a catch basin on the north side of the river at Mill Street and Gibson Avenue, near the old powerhouse.
It would collect runoff from the east end residential complexes including Hunter Creek and Centennial and some of Red Mountain…
Long and Aragon are beginning to look at funding options based on what other municipalities do, as well as other research and brainstorming exercises.
The establishment of some type of fee, along with grants and creating special districts in neighborhoods where the infrastructure needs to be done are options on the table.
Long said she plans to bring funding options, along with prioritized projects with timeframe scenarios to council sometime next year.
The fight over damming the Crystal River has been resurrected, this time before there are even any dam projects to fight over.
The Colorado Basin Roundtable voted Monday to recommend the state give $25,000 toward a water study in the Crystal River basin, despite calls from some to deny the Water Supply Reserve Fund request because of concerns that a study might conclude there is a need for water storage.
The Colorado River Water Conservation District and the West Divide Water Conservancy District brought the grant request to the roundtable in Glenwood Springs in an effort to solve a long-acknowledged problem on the Crystal: In dry years, there may not be enough water for both irrigators and some residential subdivisions.
On Nov. 18, the Gunnison Basin Roundtable gave its unanimous support to the grant application, even though its support was not necessary. Although the Crystal is in the Colorado River basin, its headwaters are in Gunnison County, and so the Gunnison roundtable decided to voice its support.
The feasibility study would look at water demands and options for creating a basinwide backup water supply plan, known as an augmentation plan. The study will look at small storage alternatives, probably off the main stem of the Crystal. Until the study is completed, it’s unclear how much water is needed for a basinwide backup supply.
But some fear that the plan could include dams and reservoirs on the free-flowing Crystal, and they opposed the grant unless storage was off the table.
Pitkin County Commissioner Kelly McNicholas Kury requested two amendments to the grant application: that any reservoir would be off the main stem of the river and would only be located downstream of the Sweet Jessup Canal diversion (about 2 miles downstream of Avalanche Creek) to preserve the possibility of designating 39 miles of the Crystal River as Wild and Scenic.
“We are not going to support this application as it’s currently written,” McNicholas Kury told roundtable members Monday. “The county continues to support Wild and Scenic designation on the Crystal.”
McNicholas Kury and two other roundtable members voted against the funding: recreation representative Ken Ransford and Eagle County representative Chuck Ogliby, who owns the Avalanche Ranch Cabins & Hot Springs in the Crystal River Valley.
The Crystal River Caucus, which doesn’t have a seat on the roundtable, also objected to the grant application and passed a resolution at its Nov. 14 meeting to that effect. In a letter to the roundtable, the caucus said it does not support the grant and urged voting roundtable members to deny the request. The caucus would, however, support a study and augmentation plan that evaluates options other than storage.
But others downplayed the threat of dams, insisting they won’t happen.
“You’re not going to see a dam on the main stem of the Crystal,” said Colorado River District President Dave Merritt. “It’s not going to happen. The river district is not predisposed to dams. There is a need for a small amount of augmentation water up there. We are talking tens of acre-feet, probably.”
No backup supply
During the historic drought of late summer of 2018, the Ella Ditch, which irrigates agricultural land south of Carbondale, placed a call on the river for the first time ever. This means, in theory, that junior-rights holders upstream have to stop taking water so that the Ella Ditch, which has water rights dating to 1885, can receive its full decreed amount.
Most junior-rights holders have what’s known as an augmentation plan, which lets them continue using water during a call by replacing the called-for water with water from another source, such as a reservoir or exchange. The problem on the Crystal is that several residential subdivisions don’t have augmentation plans.
Without an augmentation plan, these entities — which are the town of Carbondale, the Marble Water Company, Chair Mountain Ranch, Crystal River Resort, Crystal View Heights and Seven Oaks Commons — could be fined for every day they are out of priority and could potentially have their water shut off, if there is a call on the river.
Colorado Division of Water Resources Division 5 engineer Alan Martellaro said instead of each subdivision coming up with its own augmentation plan, a basinwide approach makes more sense.
“We think it would save everyone money if we had a reasonable regional solution,” he said. “It looks a lot to us that a call from the Ella Ditch is going to be more common in the future.”
To understand why some groups are opposed to even just a study whether storage is an option, it helps to review the contentious history of water development in the Crystal River Valley.
In 2011, the West Divide district and the Colorado River District abandoned their conditional water rights for nearly 200,000 acre-feet of water storage on the Crystal River after local groups — Crystal River Caucus, Pitkin County and Crystal Valley Environmental Protection Association — opposed the reservoirs tied to the conditional rights. Known as the West Divide project, the now-defunct conditional water rights were tied to a dam on the Crystal just downstream from Redstone, which would have created Osgood Reservoir, and a dam on the Crystal at Placita, which is at the bottom of McClure Pass.
To try to prevent the specter of dams coming back to haunt the Crystal in the future, Pitkin County and other local groups have pushed for a federal designation under the Wild and Scenic River Act of 1968, which requires rivers to be free-flowing. The Colorado River District opposes the designation.
“With our challenging history with both the river district and West Divide … this is why we are very nervous whenever we hear discussion of any dams on the Crystal River,” said Bill Jochems, Redstone resident and member of the Pitkin County Healthy Rivers board.
In the end, the roundtable approved the grant request. A motion to amend the request with a no-storage requirement failed.
“Obviously, storage is not the first choice,” said Ken Neubecker, the roundtable’s environmental representative and Colorado project director for environmental organization American Rivers. “But you have to look at all the options, including storage, or you’re just not being responsible.”
The two conservation districts plan to ask for a $50,000 grant from the Colorado Water Plan grant fund in early 2020 to fund the roughly $100,000 project. West Divide plans to contribute $15,000 and the Colorado River District $10,000.
Aspen Journalism collaborates with The Aspen Times and other Swift Communications newspapers on coverage of water and rivers. This story appeared in the Nov. 29 issue of The Aspen Times.
With the clock ticking on moving its conditional water-storage rights, the city of Aspen is taking steps toward developing a water integrated resource plan, or IRP.
City Council last month approved spending $81,674 to hire Broomfield-based Carollo Engineers as a consultant for the first phase of the IRP. A main goal of the plan will be to decide where to move the city’s conditional water-storage rights after a water court judge in June approved the city’s settlement with opposing parties in two water court cases. The decrees issued by the judge in those cases rule out the possibility of the city building dams or reservoirs on upper Castle or Maroon creeks.
The city has six years to finalize a plan to move the water rights and associated storage to new locations. That and the increasing effects of a hotter, drier climate, which means less water in streams, have the city feeling a sense of urgency when it comes to figuring out its water supply.
“We do have a sense of urgency, but we also recognize we are only going to get one chance to make such a large change to our system,” said Margaret Medellin, Aspen’s utilities resource manager. “We want to do it right.”
Conditional water rights
All 10 parties who settled with the city in water court, one of which was environmental group American Rivers, agreed not to oppose the city’s efforts to change its conditional water-storage rights to different sites.
Instead of flooding two pristine valleys to create reservoirs, the city has identified five other locations to where it could possibly store water. Those sites are the city golf course; the Maroon Creek Club golf course; the city’s Cozy Point open space; the Woody Creek gravel pit; and a 63-acre parcel of land next to the gravel pit, which the city bought in 2018.
“We don’t have any issue with Aspen’s plan to move forward with those conditional water rights,” said Matt Rice, director of American Rivers’ Colorado Basin Program. “That’s a decision for them and local stakeholders to make.”
Carollo Engineers was one of five firms that responded to the city’s summer request for proposals. The more than $81,000 that the City Council approved will pay for Carollo to complete only Phase 1 of the IRP, which will define goals and develop a detailed scope of work. Phase 2 would create the IRP using community input.
“Normally, when we do an IRP, we are looking at what the future looks like in terms of water needs and trying to characterize those and predict them out several decades,” said John Rehring, senior project manager and vice president of Carollo Engineers.
City officials maintain that a lack of reservoir storage is a problem.
Medellin said the lack of water-storage facilities is a big weakness in the city’s water system and that it is controversial to build dams and reservoirs “because every valley up here is beautiful.”
But, Medellin said, climate change may increase the need for water storage.
“We’ve acknowledged these storage rights are very important to the future of Aspen, especially as we start to see climate-change implications,” she said.
Carollo Engineers agrees with that assessment.
“Clearly, the city of Aspen’s system lacks the water storage it needs to reliably meet demands through a range of supply-and-demand conditions even now — before the impacts of climate change have fully taken hold,” the proposal reads.
The issue of storage came to the forefront in the Aspen community in 2012 when news broke that the city was contemplating using its conditional water-storage rights to build dams and reservoirs in Castle and Maroon valleys.
Consultants have come to different conclusions about how much water storage the city actually needs. A 2017 report by Deere and Ault Consultants, which was based on conclusions in a risk analysis by Headwaters Corporation, said Aspen needs 8,500 acre-feet of water storage. But a 2016 study by Wilson Water concluded Aspen does not need any storage.
Two other areas that the IRP will address is the vulnerability of Aspen’s water supply to natural disasters such as 2018’s Lake Christine Fire and last winter’s historic avalanches in Castle and Maroon valleys, as well as how to decrease customers’ demand for water. Even though Aspen has taken steps to reduce the use of water for outdoor irrigation through a landscape ordinance, those gains could be wiped out because in a warmer future, there will be less water flowing in local streams.
“It’s almost like you are playing this game where you, on one hand, lower the level of demand but, on the other side of the equation, climate change is decreasing our supply,” Medellin said.
Aspen Journalism collaborates with The Aspen Times and other Swift Communications newspapers on coverage of water and rivers. This story appeared in the Nov. 26 edition of The Aspen Times.
On a recent snowy morning, aquatic ecologist Bill Miller dipped what’s known as a Hess sampler into the frigid waters of Castle Creek near Aspen.
Miller stirred up the streambed with his hands, funneling the rocks, sediment and leaves — along with macro-invertebrates such as insects and worms — into the collection container.
After putting the organic material into smaller jars and giving each one a squirt of alcohol as a preservative, heferried them to a lab in Fort Collins. Scientists there will count the number and types of bugs in each sample.
“By the different species that are there, you can get a good indication of stream and water quality, and overall ecological function,” Miller said.
Miller’s work is part of a program that will monitor the health of Castle and Maroon creeks, ensuring that Aspen Skiing Co.’s increased water use for snowmaking on Aspen Mountain won’t harm the aquatic environment of the creeks. The stream-monitoring program was set out in September as a condition of Pitkin County’s approval of Skico’s Aspen Mountain Ski Area Master Plan.
“I think the idea of this is we don’t want the snowmaking to cause significant harm to the creeks,” said Andre Wille, chairman of Pitkin County Healthy Rivers board.
Aspen Mountain expansion
As part of its planned expansion, Aspen Mountain will use an additional 57 acre-feet of water per season, bringing the total average snowmaking water use to roughly 257 acre-feet. For context, Wildcat Reservoir, which is visible from the Snowmass Ski Area, holds about 1,100 acre-feet of water.
Skico is expanding its snowmaking for the 2020-21 season on 53 acres near the summit of Aspen Mountain, which will make it easier to have reliable and consistent snow coverage to ensure a Thanksgiving opening. Skico draws its water for snowmaking on Aspen Mountain from the city’s treated municipal supply, which is from Castle and Maroon creeks.
When Skico makes snow in November and December, the upside is there are fewer municipal water users pulling from local streams — outdoor irrigation season is over and holiday crowds have yet to arrive —but snowmaking uses water when natural streamflows are at some of their lowest points of the year.
“We were definitely concerned with the possibility of too much water being taken out in those early months of the winter,” Wille said.
Miller collected samples from above and below the city’s diversion dams on both lower Castle and Maroon creeks. His samples will act as a baseline against which the condition of the streams in future — and perhaps drier — years will be measured.
According to the resolution approving Aspen Mountain’s master plan, if the county’s aquatic ecologist determines, in future years, that the additional water usage is having a negative effect on stream health, the county could limit Skico’s water use to historical levels — about 200 acre-feet a year.
There is another safeguard to keep water in the river, but some say it may not go far enough to ensure stream health.
The Colorado Water Conservation Board, a state agency, holds instream-flow water rights on both Castle and Maroon creeks. And the state has determined that it requires at least 12 cubic feet per second of flowing water to protect the environment to “a reasonable degree” on lower Castle Creek and 14 cfs on lower Maroon Creek.
“We don’t feel it’s advisable to look at what the CWCB may have decreed in the past for a minimum instream flow,” said John Ely, Pitkin County attorney. “That’s not necessarily indicative from a scientific point of view of what is actually needed to maintain a healthy stream.”
That’s why the county hired Miller — who also is the longtime consulting biologist for the city of Aspen — to do its own assessment of stream health.
Ely said stream samples may not need to be taken every year — just in dry years when snowmaking could exacerbate already low flows. He estimated the annual cost of the monitoring program at about $5,000 to $10,000.
Jeff Hanle, Skico’s vice president of communications, said the company is taking steps to increase the efficiency of its on-mountain storage for snowmaking, such as adding two new ponds on Gent’s Ridge, so it won’t need to pull as much water from the city’s supply during the early season.
Although Skico and Pitkin County still need to work out the details of the stream-monitoring program, Hanle said the company is on board with preserving the ecological health of Castle and Maroon creeks.
“We would not make snow if it’s harming the stream, even if it could shorten a season,” he said. “We aren’t going to damage our home.”
Aspen Journalism collaborates with The Aspen Times and other Swift Communications newspapers on coverage of rivers and water. This story ran in the Nov. 11 edition of The Aspen Times.