Published pieces

New dust-on-snow monitoring technology coming to Steamboat lab, expanding a growing snowpack data network

Published April 23, 2021 in The Steamboat Pilot & Today and The Aspen Times

The first automated dust-on-snow monitoring technology in the mountains of northwest Colorado is expected to be installed this fall to study the impact of dust from arid landscapes on downwind mountain ecosystems in the state and in Utah.  

McKenzie Skiles, who is a hydrologist and a University of Utah assistant professor, will use close to $10,000 from a National Science Foundation grant to purchase four pyranometers, which measure solar radiation landing on, and reflected by, snow. 

These instruments will be placed on a data tower at Storm Peak Lab, a research station above Steamboat Springs that studies the properties of clouds, as well as natural and pollution-sourced particles in the atmosphere. The lab sits at 10,500 feet near the peak of Mount Werner at the top of Steamboat ski area, in the Yampa River basin. Starting next winter, live information will be transmitted to MesoWest, a data platform at the University of Utah in Salt Lake City.

This station will be the latest added to a growing network of dust-on-snow monitoring towers across the state and Utah. Such stations offer key insights to researchers studying how dust impacts the timing and intensity of snowpack melt, Skiles said. 

“My goal is to have a network of dust on snow-observation sites that spans a latitudinal gradient in the Rockies and headwaters of the Colorado River,” Skiles said.

Five towers spread around Colorado and Utah currently take in data on the solar energy absorbed and reflected by the snow. Dust particles darken the snow’s surface then absorb more energy than they do from clean snow. Such a process changes light frequencies recorded by the pyranometers. Researchers take this frequency data and run it through models to quantify how much surface dust heats snow and speeds snowmelt.

Of the currently operating stations, one is near Crested Butte; one sits on Grand Mesa above Grant Junction; two are near Silverton; and one is in the Wasatch Mountains near Alta, Utah. The sites are run, respectively, by Irwin Mountain Guides; by the U.S. Geological Survey and a collaborative user group; by the nonprofit Center for Snow and Avalanche Studies; and by University of Utah researchers.

Stations were first established in the Senator Beck Basin, near Silverton in the San Juan Mountains, which is the Colorado range most immediately downwind from the deserts of the Colorado Plateau and receives the first dust — and the most dust. In analyzing data from the two radiation towers there, Skiles and colleagues revealed that dust on snow shortened the cover by 21 to 51 days and caused a faster, more-intense peak-snowmelt outflow. In a 2017 study that also analyzed data from Senator Beck Basin, Skiles showed that it was dust, not temperature, that influenced how fast snowpack melted and flowed into rivers downstream.

The Steamboat station will fill a gap in the locations of radiation towers, Skiles said.

“We know that a lot of dust comes from the southern Colorado Plateau and impacts the southern Colorado Rockies, but we don’t understand dust impacts as well in the northern Colorado Rockies,” she said.

Since there isn’t a data station in the northwest portion of the state, “The only way to know if there’s dust there is to go and dig a snow pit,” said Jeff Derry, executive director of the Center for Snow and Avalanche Studies. CSAS runs the Colorado Dust on Snow program (CODOS), which includes the two radiation towers in Senator Beck Basin.

Three times a year, usually in mid-March, April and May, CSAS staffers tour Colorado, digging snow pits at mountain locations to assess dust conditions statewide. Since dust events continue into May, this year’s conditions are currently hard to quantify, Derry said. 

So far, this spring has been dustier than 2020; five dust events have hit the Senator Beck Basin as of April 14, compared with the three total dust events last year. As in years past, Senator Beck basin has experienced more dust events than have the sites to the northeast, according to Derry in the latest CODOS update. Yet, a recent April storm distributed dust on all sites in the state. 

Unlike the past few years, Rabbit Ears Pass — the CODOS sampling site closest to Steamboat Springs and located northwest of Bear Mountain along the U.S. 40 — has received at least as much dust as the Senator Beck Basin has, according to the CODOS update. As of the April 12-14 CODOS tour, two dust layers of moderate severity are present on the pass. That amount probably came from storms in the Uintah basin, in the Four Corners region and in Mexico’s Chihuahuan Desert, Derry said. 

These dust layers will warm the snow and have an impact on snowmelt timing this runoff season, Derry said. In order to quantify that effect, radiation data from dust-on-snow study plots, like the one planned for Storm Peak, is needed.

Dust in arid landscapes — often disturbed by human activity — travels in wind currents during storms and is deposited on downwind mountains, Skiles said. The number of dust events and mass of dust carried in storms vary from year to year depending on wind speed, the intensity of drought and the frequency of human activities that disturb surface soils, said Janice Brahney, an assistant professor at Utah State University who studies nationwide dust composition and deposition patterns.

For instance, Senator Beck Basin experienced a peak in dust events from 2009 through 2014 and a decline in recent years. This decline is probably due to storms and winds that are not strong enough to carry and deposit dust into Colorado mountains, Brahney said. 

“My sense is that a lot of the storms that are occurring in the southern United States are still occurring — they’re just not always reaching Colorado,” she said.

Dust data will provide future insights for Steamboat water policy and management

Skiles’ lab isn’t the only entity interested in the Storm Peak Lab dust-on-snow data. Kelly Romero-Heaney, water-resources manager for the city of Steamboat Springs, anticipates using the data in the city’s next water-supply master plan.

  “We update our water-supply master plan at least every 10 years,” Romero-Heaney said. “So, even if it’s another eight years of data that’s needed before we can see measurable trends, by the time we update our models, we’ll be able to integrate that data,” said Romero-Heaney.

The most current plan, released in 2019, includes forecasts for Steamboat Springs’ water supply 50 years into the future. The plan — factoring in historic streamflow data and stressors to water supply such as climate change, wildfire and population growth — concluded that the city will meet its demands through 2070.

“One thing we’re fortunate in is that we have a relatively small community for a relatively large snowy water basin,” Romero-Heaney said.

Mount Werner Water and Sanitation District supplies the city with its water, derived primarily from Fish Creek and Long Lake reservoirs, said district general manager Frank Alfone. In the summer months, the district also treats water from the Yampa River to meet irrigation demands, he said.

In order to predict Fish Creek and Long Lake reservoir levels, Alfone relies on data from the Buffalo Pass snowpack station, which is run by the Natural Resources Conservation Service, and on monthly water-supply forecasts from the National Oceanic and Atmospheric Association.

Alfone says dust on snow and the city’s water supply have “an impact now, and more so in the future,” Alfone says.

Indeed, dust levels are expected to rise throughout the West. A 2013 study revealed that since 1994, dust deposition has increased in the region, with the majority of dust lifting from deserts in the Southwest and the West, along with regions in the Great Plains and Columbia River Basin. This increase, according to the study, is probably due to heightened human disturbance of dry soils, which includes off-road-vehicle use, gas drilling, grazing and agriculture.

Increasing dust accelerates snowpack entrance into rivers, Skiles said. This earlier runoff lengthens the period when water can evaporate from rivers and lower streamflow, impacting water supply in the warmer months, according to her study, 

“What we’re finding is that runoff is happening earlier and earlier each year, and that has real implications for us come August and September, particularly if we get very little rain throughout the summer season,” Romero-Heaney said. 

Data from the widening dust on snow-monitoring network will aid water-resource managers and researchers in predicting how dust will shape future snowpack across Colorado.

“Dust does play a really significant role in hydrology. And that’s really important in the Western states, where we rely on the mountain snowpack not just for our own drinking water, but for our own functioning ecosystem,” said Brahney, lead author of the 2013 dust study.

“We anticipate some challenges for the whole basin, although we will still be able to reliably supply our customers with drinking water,” Romero-Heaney said.

Soil-moisture monitoring station high in Castle Creek Valley completes local water-research network

Published March 29, 2021 in The Aspen Times

Last summer, the Aspen Global Change Institute’s first subalpine soil-moisture and snowpack-monitoring station began transmitting live data to researchers, stakeholders and the Aspen water department.

The station, which sits at 11,500 feet on Cooper Basin Road near the edge of the Castle Creek watershed, tracks soil moisture at multiple depths; soil temperature; snow depth; wind speed and direction; air temperature; humidity; and radiative balance. That data is made available online in real time. 

“The new station fills a gap in that there wasn’t information being measured at that elevation,” AGCI research director Julie Vano said recently.

AGCI now has 10 stations covering the major elevation zones and ecosystems present in the Roaring Fork Valley.

  The stations, known as the Interactive Roaring Fork Observation Network (iRON), gather data on soil-moisture levels, which are key but understudied  variables in streamflow forecasting. In the 2020 Western Water Assessment report for the Colorado River upper and lower basins, scientists emphasized that surface soil-moisture data — critical for streamflow forecasting and for monitoring the impacts of climate change on the hydrologic cycle — was sparse.

Gathering data at all elevations throughout the Roaring Fork Valley provides scientists with a localized, clearer picture of how climate change is impacting the hydrologic cycle at the Colorado basin’s headwaters. The study of headwater areas is important because 15% of the upper and lower basins’ surface area — primarily the high mountains of the Western Slope, but also spanning mountainous areas in Utah and Wyoming — provides 85% of total annual runoff into the Colorado River.

A storehouse of data

The AGCI network gives scientists the opportunity to study how elevation and varying ecosystems shape soil-moisture retention.

“People who live in the mountains know that everything varies a lot in a pretty small geographic distance,” said ACGI community science manager Elise Osenga. “You’ll have changes in soil type, changes in plants, even changes in rainfall from one mile to the next mile over.” 

As the network continues to accumulate data, it will create a local picture of climate change’s impacts on the water cycle. Throughout the upper basin, scientists have shown that snowmelt and runoff are occurring earlier than they did between 1950 and 2000. Every degree of warming is expected to reduce upper-basin runoff by 5%. Having a data record for a specific basin will give these impacts a local focus, Vano said.

Since 2015, AGCI staffers have been submitting their data to international hydrologic and soil-moisture databases.

“Since we started sharing, over 1,800 requests for our data have been made,” Osenga said.

The ACGI is working to create partnerships with other soil-moisture monitoring basins and research institutions across the West to share data, allowing for future hydrologic studies involving intrabasin comparisons.

“Nothing is fully underway just yet,” Osenga said.

Determining climate-change trends via iRON data will take time to develop. The first iRON station was created in 2012. Of the 10, six have been installed since 2015. To detect climate trends, at least 10 years of data from all stations is needed, Vano said.

Adding to the uncertainty, the Colorado River basin has been in an extended dry period marked by frequent droughts since 2000, marking “the driest 21-year period in the Colorado River asin in more than 100 years of record keeping and one of the driest in the past 1,200,” according to a 2021 U.S. Bureau of Reclamation report on water-supply security.

“We have really short data records, and those data records exist within an already really dry period,” Osenga said of  iRON.

So, in order to gain an understanding of soil moisture in the Roaring Fork Valley, data from future potentially droughtless years is needed, Osenga said.

While drought is predicted to become more frequent and intense in the future, it is less clear how precipitation trends — which are the greatest drivers of soil moisture — will take shape. Some models indicate that precipitation could increase in the upper basin in the coming decade, which would reshape iRON’s soil-moisture data, Osenga said.

Don’t be so predictable 

While long-term trends from the Roaring Fork data remain ambiguous, yearly data provides useful insights for the Aspen water department in predicting spring- and summer-streamflow conditions.

“When I’m not in meetings and other obligations, I’m constantly looking at data,” said Steve Hunter, utilities resource manager for the city of Aspen.

To better predict spring streamflow, Hunter checks snowpack, water supply and streamflow forecasts from national organizations such as the National Weather Service (NWS), U.S. Geological Survey and the National Resource Conservation Service. Hunter utilizes data from the NRCS Snow Telemetry (SNOTEL) sites in the Roaring Fork watershed. The SNOTEL site at Independence Pass is the closest representation of the Castle and Maroon Creek watersheds given the absence of a SNOTEL site in the watersheds themselves, Hunter said. On Wednesday, the snow-water equivalent measured at Independence Pass was at 13.8 inches, which is 91% of average, calculated from data from 1981 to 2010. Snow depth, which is different from SWE, at Independence Pass was at 52 inches. At the Castle Creek iRON station, snow depth was at 53 inches.

 Hunter also tracks the information coming from iRON. Soil-moisture data ends in the fall, when frozen water begins accumulating on the soil as snow. In the fall of 2020, seven of nine stations had the lowest levels of soil moisture on iRON station record, said Osenga. (The Castle Creek iRON station was not included in analysis.) Of the two with higher water levels than prior years, one station is in an irrigated area, providing an artificial boost to moisture levels, Osenga said. 

Dry fall soil conditions mean that as snow begins to melt this spring, more water will soak in — and be absorbed by plants and the atmosphere — before running into local creeks and rivers, Osenga said. 

Hunter is holding out hope that more stormy weather could give the snowpack the boost it needs for adequate streamflow this spring and summer.

“We’re just hoping we get a lot of snow and then liquid precipitation in the spring,” said Hunter.

Deciding what’s important

While the AGCI plans on expanding its reach through collaborations, the organization does not plan to add more iRON sites in the near future. Each site has been funded by a combination of partners, including private organizations, government entities and educational interests.

“It’s supported by the community, which is really amazing,” Vano said of iRON. “You don’t see that often in the world of science. So, the community is really deciding that understanding these changes is really important.”

Toxic algae blooms in reservoirs near Steamboat detected thanks to new state protocol

Published December 31, 2020 in The Steamboat Pilot & Today

Since state officials began a more focused monitoring effort six years ago to detect toxic algae blooms in Colorado’s lakes and reservoirs, testing has documented harmful levels of such toxins three times on the Western Slope. 

Two of those toxic blooms occurred in Routt County reservoirs — first at Stagecoach Reservoir in 2019 and then at Steamboat Lake last summer, which was the first year that state park managers were required to regularly test for toxic algae. Results showing bacteria above state thresholds caused a two-week swimming closure at the popular state park.

Since 2014, toxic algae has been discovered in nine Front Range lakes or reservoirs, while the only other Western Slope bloom was found in 2018 at Fruitgrowers Reservoir in Delta County.

More research is needed to determine the causes of these recent blooms. But an increase in testing due to more stringent Colorado Parks and Wildlife (CPW) toxic algae monitoring protocol, a history of ranching around and on reservoir land, and climate change are probably contributing to the increase in recorded toxic blooms on the Western Slope.

Steamboat Lake State Park manager Julie Arington said the updated CPW monitoring and testing guidelines influenced the discovery of the toxic bloom last summer. The new guidelines, which were updated going into the season, require park managers to regularly test for toxins May through September, according to CPW officials. 

“It may have been there before (this year), but we just didn’t notice it. We hadn’t been testing for it,” Arington said. But in mid-August, when water temperatures were at their warmest, toxin levels were found to be above the recently-established thresholds and park managers shut down the lake to swimming for two weeks, until winds and cooler temperatures slowed the blooms down.

Blue-green algae that populate lakes in and of themselves are not harmful and form the basis of the riparian food web. Under certain conditions, however, the algae multiply rapidly, form blooms and produce toxins. 

 Nutrients and warming cause these blooms, said Jill Baron, a research ecologist and senior scientist with the U.S. Geological Survey. “Period.”

 Toxic algae feed off phosphorus and nitrogen, nutrients sourced from fertilizers, vehicle emissions, sewage, soil, animal excrement and plant material. If ingested in levels above state health standards, the toxins cause sickness, liver and brain damage when ingested during recreational lake activity or when drinking contaminated water.

Tracing Steamboat and Stagecoach nutrients
          Steamboat and Stagecoach reservoirs sit in the greater Yampa basin to the north and south, respectively, of Steamboat Springs. Steamboat Lake, which holds 23,064 acre-feet of water, is portioned off a creek that feeds into the Elk River, a tributary of the Yampa. Stagecoach, which holds 36,439 acre-feet of water, is a dammed section of the Yampa River. 

Nutrients deposited at the bottom of both reservoirs from decades of ranching probably contribute to the blue-green algae blooms. By the early 1880s, settlers were ranching in the Yampa Valley, including the lands that would become Stagecoach and Steamboat reservoirs, said Katie Adams, curator for the Tread of Pioneers museum. 

Steamboat Lake was constructed in 1967 with funds from the operators of Hayden Station power plant and the Colorado Division of Parks and Outdoor Recreation. It became a state park in 1972. 

The former ranch lands where Stagecoach is today were bought in 1971 by the Woodmoor Corporation, which planned to build a residential and recreational community with ski areas and golf courses, but the company went bankrupt in 1974. The site was later bought and developed by the Upper Yampa Water Conservancy District and power companies, which funded the reservoir’s construction in 1988. So, for decades leading up to the post-war era, cattle excrement was enriching the reservoir lands with nitrogen and phosphorus — nutrients that fuel the growth of blue-green algae.

Those involved in planning and constructing Stagecoach Reservoir were told algae blooms were a likelihood, said Stagecoach State Park manager Craig Preston.

“Even when they were going through the (construction) processes, they were told there would likely be algae situations, because of the nutrients in the soil,” Preston said.

Baron agrees that nutrients at the bottom of both lakes probably contribute to the blooms.

“They basically took a meadow and turned it into a lake. So, all that vegetation and organic matter on the bottom of that meadow is slowly decomposing and putting its nutrients into the lake itself,” Baron said.

Researchers are focusing on the region to determine which specific sources of nitrogen and phosphorus prompt harmful algal growth. The USGS has been collecting data on algae compositions in Stagecoach Reservoir and in the greater Yampa River watershed and will analyze possible sources of blue-green algae as part of the report, USGS hydrologist Cory Williams said. The results of the study will be published in February or March, according to Williams.

Origins and evolution of state protocol and monitoring

CPW began drafting toxic-algae protocol the summer of 2014, after a local agency found microcystin — a toxin commonly produced by blue-green algae — in Denver’s Cherry Creek Reservoir, said CPW Water Quality Coordinator Mindi May.

“At the time, we didn’t know what the numbers meant. So, we started looking around for state or federal thresholds, and there just weren’t any,” May said.

That same summer, a toxic bloom in Lake Erie contaminated the drinking water of 400,000 residents, forcing officials in Toledo, Ohio, to cut off water for three days. After these two events, May asked Colorado Department of Public Health and Environment staff to develop toxic-algae thresholds for drinking water and recreation, and traveled to state parks in 2015 to encourage staff to test for — and monitor — toxic algae during summer months. 

CDPHE developed protocol and thresholds for toxic algae in 2016, based on Environmental Protection Agency standards created in 2014. The thresholds dictate the maximum amount of toxins that lakes can contain, including 8 micrograms per liter for microcystin and saxitoxin, and 15 micrograms per liter for anatoxin and cylindrospermopsin. If lakes cross this threshold, state park managers must post danger signs and close the lake to activities involving bodily contact with the water until tests show that toxins fall below harmful levels, May said.

In 2018, the CDPHE developed a database to compile monitoring and testing efforts in Colorado reservoirs and track the occurrence of toxic-algae blooms since 2014. Data from park managers’ toxin tests are included, along with data collected by CDPHE officials and other local and federal agencies, said MaryAnn Nason, CDPHE’s communications and special projects unit manager.

“We really learned a lot in those early years, and we have a lot more resources now to monitor and test for toxins,” May said of CPW’s and CDPHE’s efforts.

Western lakes lack data but will feel burn of climate change

CDPHE data shows an increase in toxic blooms from 2014 to 2020 and hints that these blooms are spreading west. Last summer recorded seven toxic blooms, compared with four in 2019 and one in 2018. Yet, increases could also be due to increased monitoring and testing over the years and due to the new 2020 protocol. For instance, 52 lakes were monitored for toxic algae in 2014, compared with 73 last summer.

More data is needed to determine how climate change and nutrients will interact to produce toxic blooms, and determine the impacts this will have on drinking water and summer recreation for high country and Western Slope lakes. 

It is likely that climate change will spur more toxic blooms in the West. In a 2017 study of 27 Rocky Mountain lakes, researchers project that climate change will cause average annual lake-surface temperatures to increase 41% by 2080, with dramatically warmer water in the summer and 5.9 fewer ice-free days with each passing decade.

Warmer lakes create a widened window for toxic algae to bloom. A separate national study, also from 2017, predicts that rising air temperatures and the resultant warmer waters will increase toxic-bloom occurrence from an average of seven days per year in U.S reservoirs now  to 16-23 days in 2050 and 18-39 days in 2090.

Long-term solutions for current and future blooms include placing limits on greenhouse gas, as well as nitrogen and phosphorus emissions, Baron said. Short-term solutions include waiting for blue-green algae to stop producing toxins and keeping visitors out of the water while they do, said May.

As frosty temperatures inhibit algal growth, Steamboat and Stagecoach park managers get a break from thinking about the turquoise-tinted toxins. In May, they’ll start the second season of following the parks’ new protocol, May said.

 Regarding last summer’s toxic bloom, Steamboat Lake State Park’s Arington said, “I think this won’t be the last year that we see it.”

Gunnison River, with elevated selenium levels, faces review for reclassification

Published December 3, 2020 in The Aspen Times

State water quality officials will soon evaluate whether two water improvement programs in the Gunnison River have successfully reduced a chemical toxic to endangered fish.

The Colorado Department of Public Health and Environment (CDPHE)’s Water Quality Division is analyzing five years of data on selenium levels in the Gunnison River. Division staff break rivers into segments, analyzing selenium levels in each one, according to Skip Feeney, assessment work group leader for the Water Quality Control Division.

 If levels stay at or below the state standard of 4.6 micrograms per liter for each analyzed river segment, the river will be reclassified from a water body that threatens aquatic life to one that meets state water quality standards, said Feeney.

“Our goal is to provide an accurate, defensible proposal to the commission and let the commission make an informed decision,” Feeney said.

A key segment for members of the Selenium Management Program, a collaboration between government agencies, nonprofits and stakeholders, is the main stretch of the Gunnison river. This segment winds for 58 miles from Delta to Grand Junction, and was designated as essential to pikeminnow and razorback survival by the Fish and Wildlife Service (FWS) in 1994.

Historically, the segment has contained selenium levels toxic to the two fish species, according to Dave Kanzer, deputy chief engineer for the Colorado River Water Conservation District and Selenium Management Program member. 

 Yet, the past five years of USGS data show selenium levels have stayed below 4.6 micrograms per liter. Each yearly average was below 4.6, with the average for all five years totalling 3.2 micrograms per liter, according to Aspen Journalism analysis. 

“This type of analysis is not directly applicable to the CDPHE listing methodology, but it does tell a good story,” said Kanzer.

To calculate the final selenium load for each segment in the Gunnison river, CDPHE is synthesizing data from the past five years of data from the USGS, Colorado River Watch, United Companies and the water quality control division, Feeney said. United Companies, a Grand Junction-based construction company, is required by the state to monitor selenium levels near the gravel pits the company operates, according to United Company environmental specialist Tyra Bartuska.

From there, CDPHE calculates selenium concentrations as 85th percentiles, meaning the value that 85% of the data values from 2015 to 2019 fall below, said MaryAnn Nason, CDPHE Communications & Special Projects Unit Manager. During the last regulation cycle, which used data from 2010 to 2015, the 85th percentile value for selenium in the mainstem of the Gunnison was 6.7 micrograms per liter, 2.1 micrograms above the state standard, Nason said. 

Selenium’s origins and pathway to the rivers

Selenium is a natural element found in Mancos shale, a soil type common in the Uncompahgre and Grand valleys, found in the Gunnison river basin. When irrigators transport water to and through their farms in open canals, selenium dissolves into the water and percolates into groundwater or gets carried into drainage ditches that discharge into the Gunnison river.

In the Gunnison river and its tributaries, selenium accumulates at levels toxic to the endangered Colorado pikeminnow and razorback sucker, Kanzer said. 

“Where we have good flows of water, [selenium] concentrations are not an issue because of dilution. But smaller tributaries, smaller water areas or backwater areas where you don’t have good circulation, you get selenium that can accumulate in the ecosystem, really in the sediment and in the food web,” Kanzer said.

 High selenium levels threaten the survival the Colorado pikeminnow and razorback sucker, who exist only in the upper Colorado River basin, said Travis Schmidt, research ecologist for the Wyoming-Montana Water Science Center. The species swim between the Colorado and Gunnison rivers, accumulating selenium and transferring the element to their offspring.

Selenium gathers in fish tissues when females ingest algae or smaller fish. It then is transferred to offspring during the egg laying process, Schmidt said.

“Selenium replaces sulfur in protein bonds, so anything that lays an egg can transfer a lot of selenium to its progeny,” Schmidt said.

Once transferred to fish eggs, the element causes neurological, reproductive, and other physiological deformities in a significant proportion of both fish species, Schmidt said. A study that analyzed fish tissue samples collected by federal and state agencies from 1962 to 2011 found 63% of Colorado pikeminnows and 35% of razorback suckers exceeded healthy selenium tissue concentrations in the upper Colorado river basin.

The Selenium Management Program and Salinity Control Programs work to reduce selenium loads 

Selenium was first addressed by the US Fish and Wildlife Service (FWS) in 2009 in a document written for the Bureau of Reclamation. The document analyzed the effects of the Aspinall Unit, a series of three dams on the upper Gunnison River, on Colorado pikeminnow and razorback sucker recovery. In the document, the service concluded that in order to comply with the Endangered Species Act, the Bureau of Reclamation had to increase spring flows downstream of the Aspinall Unit and initiate a management program to reduce selenium in the Gunnison --- the Selenium Management Program, founded in 2009.

“It’s a two-prong type of plan,” said Kanzer of the program’s goals.

The first objective is to meet the state standard for dissolved selenium throughout the Gunnison river basin, and particularly for the 58-mile main segment of the Gunnison, said Kanzer. The second goal is to help transition the pikeminnow and razorback sucker from endangered to self-sustaining populations, Kazer said.

To achieve the first goal, SMP members help irrigators obtain funding from the Bureau of Reclamation and Department of Agriculture, said Lesley McWhirter, environmental and planning group chief for the Bureau of Reclamation Western Colorado Area Office. Individual farmers can apply for funding for on-farm irrigation projects through the Department of Agriculture, while ditch companies can apply for funding projects that deliver water to farms through the Bureau of Reclamation’s Salinity Control Program.

“The ditch company is basically a group of individual farmers who have banded together to manage their ditch. They operate the ditch company out of somebody’s kitchen table,” said Paul Kehmeier, a farmer in Delta County.

The Salinity Control Program began in 1974 with the goal of reducing salt loading into the Colorado River basin. The program awards grants to ditch companies every two to three years. In the last grant cycle in 2019, the Bureau of Reclamation awarded 11 ditch companies $37 million to line irrigation systems. Of the 11, 8 were located in Mesa, Montrose, and Delta counties, where the Gunnison River runs, according to McWhirter.

Kehmeier received Bureau of Reclamation funding to line a ditch running to his farm in 2014. The process took five years and 1,400 hours of labor, Kehmeier said.

“I am very happy I did it — it’s worth it. I’ll be happier as the years go by and the memory of how much work it was fades away a bit,” Kehmeier said.

Mancos shale is rich in salt and selenium. Therefore, when farmers receive funding to reduce salt loads, selenium often decreases as well. This is exemplified by a USGS analysis, that found selenium loads to have decreased by 43% from 1986 to 2017, and by 6,600 pounds per year from 1995 to 2017.

 “The selenium control is a happy, fringe benefit of salinity control,” Kehmeier said.

Selenium Management Project members help farmers learn about and obtain funds for irrigation improvement projects, McWhirter said. This, along with selenium data gathering and analysis and facilitating meetings between government agencies, nonprofits, and stakeholders, is a main way the SMP works to reduce selenium in the Gunnison river, said Kanzer.

CDPHE to submit proposal by January

CDPHE plans to submit its proposal to the Water Quality Control Commission in early January, Nason said. 

“I don’t know yet what the water quality status is looking like. That’s just part of the process — we’re just getting started,” Feeney said.

If the main segment of the Gunnison river is found to have selenium levels below the state standard, it would mean the SMP is closer to obtaining the dual goals of fish protection and selenium reduction, Kanzer said.

Even if the main segment of the Gunnison is reclassified, the Selenium Management Program will continue efforts to reduce selenium in the Gunnison basin, Kanzer said. The Colorado pikeminnow and razorback sucker depend on the entire Gunnison basin, and therefore other segments containing toxic selenium levels require reduction efforts. If new research comes out showing fish are harmed by selenium at levels lower than 4.6, the state could lower the selenium standard, reclassifying segments of the Gunnison as a danger to aquatic life, Kanzer said.

“The jury’s still out — we’re still trying to understand what levels are acceptable and not acceptable. There’s always room for refinement of that standard, and that dialogue is ongoing,” Kanzer said.

After the Division submits its proposal to the Commission, the proposal will then be released to stakeholders and anyone who has applied to receive hearing notices or track Colorado’s regulations. The public can submit their own proposals or comments by emailing the Commission. In May, the commission will review all proposals and comments to make a decision on the river segment’s 2020 status, Feeney said.

Aspen water users meet Stage 2 cutback goals, cutting use by 20% since Sept. 1

Published October 11, 2020 in The Aspen Times

An analysis of five weeks of Aspen water-treatment plant data shows that local water users cut consumption by an average of 20% in the four weeks after Stage 2 water restrictions took effect, compared with the week before the stricter regulations were in place.

However, year-over-year data shows that water use in 2020, over the course of the past five weeks, was down by smaller amounts compared with the non-drought year of 2019.

Stage 2 water restrictions began Sept. 1, with the goal of reducing water use by 15% to 20% compared with “current use,” according to a news release announcing the restrictions.  

That appears to have been achieved, as average daily water use was 5.86 million gallons from Aug. 24 to Aug. 30, according to water-treatment plant data provided by city of Aspen staff and analyzed by Aspen Journalism,. Average use dropped to 5.08 million gallons per day the following week and to 4.7 million gallons per day over the four weeks from Aug. 31 through Sept. 27.

Comparing average daily water use with a non-drought year provides further context when examining the degree to which restrictions have influenced water use in recent weeks. Aspen Journalism’s analysis of the city’s daily treated volumes included totaling water use on a per-week basis and finding the average consumption per day for a given week. Those numbers were compared to average daily totals from corresponding seven-day periods in 2019, a non-drought year in which water restrictions were not in place for the utility’s approximately 4,000 customers in the city of Aspen and surrounding neighborhoods. 

That analysis showed an average decline of 10% when comparing five weeks in 2019 versus 2020. However, the differences between weekly totals from year to year varied considerably. In addition, a large decline in weekly water use in 2020 compared with 2019 often corresponded with a burst of rain or snowfall, levels that were sourced from National Oceanic and Atmospheric Administration data. For instance, over the week of Sept. 7-13 weekly water use declined by 36% from 2019 to 2020. This steep decline is probably related to the three-day snowstorm that occurred that week in 2020, which dropped on the city a cumulative 8.5 inches of snow Sept. 8-10, according to NOAA data. 

In contrast, the week of Sept. 21 in both 2019 and 2020 saw neither rain nor snow, according to NOAA data. That week in 2020, the city used 6.2% less water than in the same week in 2019, according to Aspen Journalism’s analysis. Precipitation levels were similar for the five weeks spanning late summer and early fall, with 2020 having two more days and 0.7 more inches of rain compared with 2019, according to NOAA data.

Declines in water use may relate to rainfall and snowfall since weather events prompt the city’s parks and open space department and residents to stop or reduce watering to parks, gardens and open space, said Steve Barr, the city of Aspen’s parks operations manager. Because approximately 60% of total municipal water is diverted to parks, landscapes and gardens, rain and snowfall prompt reduced water use and probably correspond to declined treatment-plant figures.

“A period of rain (in late August) allowed us to shut down irrigation for three or four days. Truly, this saves the largest amount of water,” Barr said. Yet, more data would need to be analyzed in order to draw statistically sound conclusions about the relationship between weather and water use for the entire city water system, said Steve Hunter, utilities operations manager for the water department.

Due to the many factors that influence treatment-plant numbers, it is difficult to discern from the data how resident behavior changed after the Sept. 1 water restrictions and how behavioral changes influence city water use, Hunter said.

City population, visitation, humidity, weather and special events also influence the daily volume of treated water, according to Hunter.

“Just like our weather, no two days are exactly the same,” he said.

The reduction targets identified with Stage 2 restrictions are meant to give water users a goal to hit compared to their normal usage, according to water plant officials.

Community adaptation efforts 

Aspen City Council enacted Stage 2 water restrictions after the U.S. Drought Monitor on Aug. 18 classified all of Pitkin County to be in extreme drought. The goal of the restrictions is to protect the streamflow of Castle Creek, which provides the majority of Aspen’s water, with flows throughout the Roaring Fork River basin running 40% to 70% below median, according to a memo from the utilities department concerning the water restrictions. 

In 1997, the city agreed with the Colorado Water Conservation Board to maintain 12 cubic feet per second on Castle Creek, except in extreme drought conditions, according to the state resolution. Dropping below this rate threatens the aquatic ecosystem, as warmer waters stress native fish populations and alter the aquatic environment through increased algal blooms, according to Brad Udall, a water and climate research scientist at Colorado State University.

Many local businesses report following Stage 2 guidelines, which may be associated with the 20% decline in water in the four weeks after the week of Aug. 24. The restrictions put residents and businesses on a staggered watering schedule and prohibit the construction of new landscapes and water systems, as well as prompt other regulations. (Residents and businesses, for example, cannot wash sidewalks with treated city water.) Managers and directors at Aspen Alps, The Gant, Limelight Hotel, Aspen Mountain Lodge and Aspen Meadows Resort said they follow the new protocol.

 “Everyone cares about water use and is very compliant with water restrictions,” said Aspen Mountain Lodge general manager Allison Campbell. “We see it when we’re touring around our state, how dry we are,” 

Many businesses are implementing additional measures to reduce water. Staffers at Aspen Mountain Lodge winnowed their watering window to 15 minutes every three days, compared with every other day required by Stage 2, according to Campbell. At Bumps restaurant, which sits at the base of Buttermilk Mountain, staffers are testing new technology that reduces the quantity of water needed to thaw food, according to Ryland French, energy manager at the Aspen Skiing Company. Businesses could not provide data for these reductions, as many do not collect daily water data but make changes based on the monthly water bill from the Aspen utilities department, according to Campbell, French and Aspen Meadows Resort general manager Jud Hawk.

Other major water users, such as the city golf club and the parks and open space department, have enacted new water practices following the Stage 2 announcement. Golf club staffers cut irrigation to native plants on the course and reduced water to the driving range by 75%, from 62,667 gallons dispensed on the driving range each night to 15,667, according to golf director Steve Aitken.

After Sept. 1, the parks department shortened watering times and limited those periods to every other day. Staffers continued low water-use practices established during the 2018 drought, such as limiting water to native-plant zones, Barr said. From this past August to September, the department reduced irrigation to parks and gardens by an average of 43%, according to data provided by the parks and open space department. The department used less water in 83% of Aspen parks and gardens in September compared with August, according to parks department data.

More changes needed to maintain streamflows

This summer is not the first time that the city of Aspen has tried to meet water-use reduction targets. In 2013, the water department enacted water restrictions with a 20% reduction goal. The city did not meet this target, according to a 2016 water-availability study by the Wilson Water Group. In 2015, the water department lowered the Stage 2 reduction goal to 15%, according to the 2016 study.

The water department also enacted Stage 2 restrictions on Aug. 13, 2018. No analysis was conducted on whether the city met the 15% reduction target, according to Tyler Christoff, director of utilities for the water department. 

Despite current drought conditions, Castle Creek’s streamflow remains above the state-mandated minimum level. The creek averaged 35.6 cfs in the five weeks from Aug. 24 to Sept. 27, with a minimum cfs of 32 the week of Sept. 21, according to water department data. 

The days of Aug. 24 to Sept. 27 fall within the city’s peak water-use period, which runs from June to September, according to the 2016 water availability study. Higher temperatures and evaporation rates mean that Aspen’s parks and landscapes demand more irrigation, Barr said. Last week, the parks department began blowing out and shutting off its irrigation system for the winter, according to Barr. This may cause a decline in demand for city water.

While current drought conditions did not endanger running below the minimum instream flow, studies show that climate change will demand revisions to city water sourcing and use in order to keep Castle Creek above 12 cfs.

Temperature is predicted to rise throughout Colorado by 2.5 to 6.0 degrees Fahrenheit by 2065, according to a report by the research institute Western Water Assessment. Rising temperatures increase evaporation in all forms, transferring water from streams to the atmosphere, said Udall.

“Under a warming climate, the atmosphere has a greater thirst for water. It wants to hold more water as it warms,” he said.

Rising temperatures and the resulting increased evaporation can be expected to reduce Castle Creek’s streamflow by 35% by 2065, according to a 2017 study done by Headwaters Corporation for the city of Aspen. This reduced streamflow, in conjunction with population growth, will lower Castle Creek’s streamflow below 12 cfs, according to a 2016 water availability study by Wilson Water Group. Yet, 12 cfs can be maintained if the water department draws more municipal water from local wells and implements a water-reuse program, where the city golf course is irrigated by upcycled wastewater treatment plant water instead of water from Castle Creek, according to the 2016 study. While the 2016 study concludes that Castle Creek’s minimum streamflow can be maintained with these mitigatory actions, Aspen officials in 2018 asked the state for rights to 8,500 acre-feet of water storage to prepare for the effects of climate change.

“In extreme or prolonged drought, reservoir storage would help create a more resilient water supply for the Aspen community,” Hunter said.

The Wilson study’s authors also suggest implementing Stage 2 or Stage 3 water restrictions to maintain Castle Creek’s instream flow. Stage 3 water restrictions aim to reduce water use by 20%. But the authors add that if city water users fall short of the target reductions, well water can fill the deficit to ensure the required 12 cfs. 

Stage 2 conditions will last as long as Pitkin County remains in extreme drought, which will probably be into 2021, Hunter said. In April, the water department will assess winter snowpack — which is predictive of spring and summer streamflow — and will decide to continue State 2 or lift it, said Hunter.

Hunter believes the ordinance unites the city in environmental goals. 

“We believe the community’s knowledge and participation in conservation practices creates a more resilient future,” he said.  

Pitkin County launches project to restore ancient wetland at North Star Preserve near Aspen

Published September 5, 2020 in The Aspen Times

On a recent morning, Liza Mitchell of Pitkin County Open Space and Trails rolled out fiber matts over a soil-filled portion of a ditch in the North Star Nature Preserve, adding a final layer to a wetland plug that the natural resource planner and ecologist and her team had been working on for the three weeks prior. 

The plug is the central component of the program’s fen-restoration project, which aims to enhance the wetland’s ability to provide habitat, store and filter groundwater, and sequester carbon.

While North Star is known as an idyllic paddleboarding and beach destination, 77% of the preserve is closed to public access. This includes the property west of the Roaring Fork River, where the fen sits. 

The preserve’s 245 acres function primarily to protect native species and ecosystems. The first 175 acres of the preserve were bought by the Nature Conservancy in 1977. In 2001, Pitkin County Open Space and Trails and the city of Aspen jointly purchased the 70 acres below the initial property, creating the current North Star Nature Preserve, according to the 2020 North Star management plan.

“It’s for wildlife,” Mitchell said of North Star.

Critical to the nature preserve 

Aligning with the goal of conservation, Open Space and Trails staff identified the North Star fen as a site for ecological restoration. Situated in the northwest corner of the property, the 14-acre fen, which is a peat-filled wetland, is populated with sedges, reeds and grasses. 

The wetland is critical to the entire preserve, providing wildlife habitat, water filtration and flood mitigation. In dry months, groundwater stored in the fen percolates into the Roaring Fork River, benefiting the watershed and its thirsty users, Mitchell said.

Yet, due to human alterations to the watershed and North Star, the fen is drying out. In 1936, two tunnels, multiple canals, and the Grizzly and Lost Man reservoirs were completed as part of the Independence Pass Trans-Mountain Diversion System. The system moves water from the upper Roaring Fork River basin to the east side of the Continental Divide, satisfying the water needs of Colorado’s largest cities, according to the 2020 management plan. 

This system diverts as much as 40% of the Roaring Fork’s headwaters upstream of the preserve, reducing the volume of river water that flows into the property and saturates the fen, Mitchell said.

The fen underwent further drying in the 1950s, when the preserve was a private ranch owned by James Smith. Smith dug ditches through the fen for pasture and hay cultivation, and those ditches continue to drain standing water into the Roaring Fork, according to Mitchell.

Saturation solution

The wetland plug combats the drying by slowing the outflow of water from the fen into the Roaring Fork River. Mitchell, two staffers from Basalt-based Diggin It Riverworks and two ecological consultants began the plug construction Aug. 10. The first week, the team filled 130 feet of the main ditch with a mixture of locally sourced and imported soil. In the second and third weeks, the team added a layer of local soil, scattered native plant seeds and sealed it all with hay, mulch and matting, Mitchell said.

“It’s been a pretty quick project,” she said. “We’ve really tried to get in, get out and minimize disturbance as much as possible.”

6,700 years of carbon sequestration

The wetland plug increases saturated conditions in the fen, or the presence of standing water, enhancing the fen’s ability to provide ecological services to the preserve. For instance, saturated conditions allow fens to function as carbon sequesters by storing peat, or carbon-rich plant material. 

Peat accumulates at a rate of 8 inches per 1,000 years, according to David Cooper, wetland ecologist and professor at Colorado State University. With 53 inches of peat soil, the North Star fen is estimated to be 6,700 years old, according to a Pitkin County news release.

“Peatlands make up about 5% of the land surface of the world,” Cooper said, “but almost 45% to 50% of all the soil carbon on Earth is in peatlands.” When fens dry up, the carbon stored as peat is released as carbon dioxide, contributing to global warming, he said. 

Saturated conditions also support wildlife. Standing water creates the ideal habitat for native plants, such as beaked and blister sedge, as well as native amphibians and waterfowl. Saturated conditions suffocate canary grass, an invasive species that spread increasingly through the fen as it dries up, Mitchell said.

Wet by standing water, fens filter groundwater. The peat body removes excess nitrogen as well as heavy metals that would otherwise accumulate in watershed fish populations, Cooper said. 

A positive for North Star neighbors

Mitchell anticipated finishing the construction phase of the restoration project this past week. She plans to place wattles, or cylinders of hay, across the wetland plug to prevent soil and seed erosion. She will also add hay bales and cylinders to the fen’s two smaller ditches to retain water and provide a surface for native plants.

After this construction phase, a hydrologist and botanist hired by Open Space and Trails will monitor the fen for three years. The consultants will conduct studies and submit reports to the U.S. Army Corps of Engineers, which issued the initial permit for the project in 2018, according to Mitchell.

In the spring of 2021, Open Space and Trails staffers hope to get the local community involved with the project by having volunteers plant native sedges and rushes over the plug. 

Already, community response to the restoration project has been very positive. Even without physical access to the fen, neighbors are excited about the prospect of improving habitat for wildlife, such as blue heron and elk, which they enjoy watching from their windows, Mitchell said.

“North Star can get a lot of negative attention surrounding the paddleboarding and recreation use, so it’s really nice to have another project that there seems to be widespread agreement on,” Mitchell said. “Everyone can get behind that it’s a pretty light touch for a pretty big benefit.”