Posts tagged United States
CU-Boulder wins $1.4 million NSF award for climate change, water sustainability study
Oct 10th
The University of Colorado at Boulder has been awarded $1.4 million for a new study on how changes in land use, forest management and climate may affect trans-basin water diversions in Colorado and other semi-arid regions in the western United States.
The grant, part of the National Science Foundation-U.S. Department of Agriculture Water Sustainability Climate Program, was awarded to Assistant Professor Noah Molotch of the geography department. Molotch and his team will be identifying thresholds, or “tipping points,” of change in land use, forest management and climate that may compromise the sustainability of the policies and procedures that dictate the timing and quality of water diverted from Colorado’s West Slope to the Front Range.
Molotch said that in Colorado and semi-arid regions around the world, trans-basin water diversions that redirect water from areas of surplus to areas of demand are based on policy agreements and infrastructure operations made under climatic and land use conditions that may differ considerably from conditions in the near future. Measurements over the past 50 years, for example, suggest a broad-scale reduction in snowpack water storage in the western U.S. because of regional warming temperatures, a trend due in part to a shift from snowfall to rainfall, he said.
The Colorado Big Thompson Project depends upon a dwindling supply of Western Slope snowpack.
In addition, land-cover changes associated with population growth, fire suppression and mountain pine beetle outbreaks have altered the hydrology of mid-mountain ecosystems in the West, said Molotch, who also is a scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. CU is teaming up with the National Center for Atmospheric Research in Boulder on the NSF-funded project.
The NSF award comes on the heels of a May 2012 agreement between water managers in Summit and Grand counties on Colorado’s West Slope and in the Denver area on how best to share water from the Colorado River basin. “This is a great example of communities that historically battled for water resources coming to the table in a good faith effort to find solutions to water allocation issues,” said Molotch. “These groups have no pretenses about the potential impacts of climate change and realize we can’t afford to bury our heads in the sand on this issue.”
Collaborators on the project include Patrick Bourgeron and Mark Williams, fellows at CU-Boulder’s Institute of Arctic and Alpine Research, and David Gochis, Kathleen Miller and David Yates of NCAR.
A study led by Molotch published Sept. 10 in Nature Geoscience tied forest “greenness” in the western United States to fluctuating year-to-year snowpack. The study indicated mid-elevation mountain ecosystems — where people increasing are building second homes and participating in a myriad of outdoor recreational activities — are most sensitive to rising temperatures and changes in precipitation and snowmelt.
“We found that mid-elevation forests show a dramatic sensitivity to snow that fell the previous winter in terms of accumulation and subsequent melt,” said Molotch, also a fellow at INSTAAR. “If snowpack declines, forests become more stressed, which can lead to ecological changes that include alterations in the distribution and abundance of plant and animal species as well as vulnerability to perturbations like fire and beetle kill.”
Colorado snowpack was at an all time low this past winter
As part of the new award, Molotch and his team will evaluate regional climate models in the mountain West developed at NCAR in an attempt to make temperature, precipitation and snowpack projections “more robust,” Molotch said. While the efficiency of water in trans-basin diversion projects in the western U.S. has in the past been enhanced by the natural storage of moisture in mountain snowpack that allowed for a slow, steady delivery of water into the system, warming temperatures are already causing this beneficial “drip effect” to be greatly reduced, he said.
If the winter temperatures are hovering around 15 degrees Fahrenheit and the climate warms by a few degrees, for example, there will be negligible impact on snowpack, Molotch said. But if temperatures hover near freezing, slight temperature increases can trigger earlier snowmelt, and precipitation that used to be in the form of snow turns to rain, significantly affecting trans-basin water diversion activities.
“One of the most interesting aspects of this project to me is the changes we are seeing in the ‘wildland-urban interface,’ particularly in Colorado,” he said. “There is some irony that Front Range people who have built second homes in Summit County, for example, may actually start to have an effect on the water they have relied on to be piped through the Continental Divide to the Denver area.”
Burned forests can cause early runoff
In addition to providing land and water resource decision makers with projections on how future water supply and demand will change in the future, the NSF-funded project will provide a unique educational experience for graduate students, Molotch said.
“We have climate change, snowpack, changes in land use, all feeding into the pipeline that is bringing water to Colorado’s Front Range,” he said. “As the two main stressors, climate change and land use increase, there is the possibility of pushing the systems into an unsustainable state.”
Boulder completes project to modernize historic hydroelectric facility
Oct 4th
The City of Boulder recently completed a 2.5-year modernization project of its historic Boulder Canyon Hydroelectric (BCH) facility with the help of a $1.18 million American Recovery and Reinvestment Act (ARRA) grant from the U.S. Department of Energy (DOE). Originally built in 1910, the BCH facility was in need of upgrading if it was to continue to be operable. Without a new turbine and generator, operation of the facility was expected to cease within five years or less.
“Hydropower resources are an important part of President Obama’s all-of-the-above energy strategy to develop all of America’s energy resources. The completion of this important water power project in Colorado demonstrates how investments in America’s clean energy economy are helping to create jobs, diversify America’s energy portfolio and strengthen American energy security,” said David Danielson, assistant secretary for energy efficiency and renewable energy at the U.S. Energy Department.
Boulder’s historic hydrppower plant
The BCH facility was originally built by the Central Colorado Power Company for the sole purpose of hydroelectric power production as part of the Boulder Canyon Hydroelectric System. The system began delivering water for Boulder’s municipal water supply in the 1950s. Over the years, the system was owned and operated by numerous companies, and in 2001, the City of Boulder purchased the system from Public Service Co. of Colorado and incorporated it into its hydroelectric program.
“The Boulder Canyon Hydro Facility is extremely unique due to its age, its history, and where and how it was constructed,” said Director of Public Works for Utilities Jeff Arthur. “The effort to upgrade the turbines was arduous and complex. Obviously, the city was concerned with continuing operations at the facility, increasing power generation, and improving safety, but equally as important, was preserving the historical significance of the plant itself. This is a facility the community should be proud to own.”
The modernization project included removing one of two pre-existing 10 megawatt turbine/generators and replacing it with a new five megawatt turbine/generator. The new five megawatt turbine/generator is more appropriately sized for the plant’s power generation and will generate up to 583,000,000 kilowatt hours of electricity during its 50-year lifespan. This will, in effect displace the need to burn more than 300,000 tons of coal (the amount needed in a traditional coal-fired plant to produce the same amount of energy). Despite its smaller size, it should also generate up to 30 percent more energy because it is more efficient. The pre-existing turbine/generators were more than 70 years old. One of the original turbine/generators failed in 2000 and was not repaired at that time, but it will remain on site for historical purposes.
Other improvements to the facility included enhanced lightning protection; removal and replacement of aging transformers and an old oil storage tank; upgraded wiring; installation of a state-of-the-art turbine isolation valve; and installing remote monitoring and operation equipment.
The total project cost was approximately $5.155 million and was funded by city water utility funds in addition to the ARRA grant. The ARRA funding was announced by the DOE in November 2009 when it awarded grants to seven different hydropower projects throughout the country.
Approximately 35,000 new work hours were created as a result of the project, or approximately seven full-time jobs. This number does not include the hours needed by subcontractors or the associated work hours created or preserved by using materials that are manufactured in the United States, as this project did.
“The city is grateful for the funding support we received from the Department of Energy,” said City Manager Jane Brautigam. “Without that support, completing this complex project would have been difficult, if not impossible. As with most of our capital projects, Boulder places a high level of importance on leveraging local funds with other funding sources so that we can make improvements that appeal to the greater good of the community. We are all proud of this project and expect to see this facility continue its important role of providing our community with clean energy well into the future.”
Boulder’s Hydro Program
Beginning in the early 1980s, Boulder recognized the potential for hydroelectric energy generation within its water system and began developing facilities to produce electricity as a by-product of its water utility operations. Today, Boulder owns and operates eight hydroelectric facilities. These hydroelectric plants produce environmentally friendly hydroelectricity by making use of pressure developed in the water supply pipelines due to the large elevation drop between the city’s water sources in the mountains and delivery points on the plains. This pressure must be reduced to treat and deliver the water and would otherwise be wasted through pressure-reducing valves. Revenue from the sale of the electricity produced by the hydro plants allows the city to maintain lower water rates for its customers.
By the end of 2011, the city had generated approximately 612,531,577 kilowatt hours (kwh) of electricity since its first hydroelectric project began operation in 1985. Sale of this power has produced approximately $27,095,110 of revenue and has also provided environmental benefits by displacing the need to burn approximately 306,266 tons of coal, preventing the greenhouse gas emissions that would have resulted from traditional coal-fired power generation facilities.
The BCH facility is located on Boulder Creek west of the city. The plant’s power is generated using water diverted at Barker Reservoir that is transported approximately 11.5 miles in the Barker Gravity Pipeline and experiences a 1,800-foot elevation drop to the BCH building.
CU study: Global warming increasing heavy metals in streams
Sep 7th
Increase in metal concentrations
in Rocky Mountain watershed
tied to warming temperatures
in Rocky Mountain watershed
tied to warming temperatures
Warmer air temperatures since the 1980s may explain significant increases in zinc and other metal concentrations of ecological concern in a Rocky Mountain watershed, reports a new study led by the U.S. Geological Survey and the University of Colorado Boulder.
Rising concentrations of zinc and other metals in the upper Snake River just west of the Continental Divide near Keystone, Colo., may be the result of falling water tables, melting permafrost and accelerating mineral weathering rates, all driven by warmer air temperatures in the watershed. Researchers 
observed a fourfold increase in dissolved zinc over the last 30 years during the month of September.
Increases in metals were seen in other months as well, with lesser increases seen during the high-flow snowmelt period. During the study period, local mean annual and mean summer air temperatures increased at a rate of 0.5 to 2.2 degrees Fahrenheit per decade.
Generally, high concentrations of dissolved metals in the Snake River watershed are primarily the result of acid rock drainage, or ARD, formed by natural weathering of pyrite and other metal-rich sulfide minerals in the bedrock. Weathering of pyrite forms sulfuric acid through a series of chemical reactions, and pulls metals like zinc from minerals in the rock and carries these metals into streams.
Increased sulfate and calcium concentrations observed over the study period lend weight to the hypothesis that the increased zinc concentrations are due to acceleration of pyrite weathering. The potential for comparable increases in metals in similar Western watersheds is a concern because of impacts on water resources, fisheries and stream ecosystems. Trout populations in the lower Snake River, for example, appear to be limited by the metal concentrations in the water, said USGS research biologist Andrew Todd, lead researcher on the project.
“Acid rock drainage is a significant water quality problem facing much of the Western United States,” Todd said. “It is now clear that we need to better understand the relationship between climate and ARD as we consider the management of these watersheds moving forward.”
Warmer temperatures and earlier snowmelt runoff have been observed throughout mountainous areas of the western United States where ARD is common, but it is not known if these changes have triggered rising acidity and metal concentrations in other “mineralized” watersheds because of lack of comparable monitoring data, according to the research team.
CU-Boulder Professor Diane McKnight, a collaborator on the project, has generated much of the upper Snake River data through research projects conducted with her students since the mid-1990s. McKnight said students in her environmental engineering and environmental studies class like Caitlin Crouch — a study co-author who received her master’s degree under McKnight — are highly motivated to understand ARD problems.
“Student can see that their research will have direct applications to addressing a critical issue for Colorado,” said McKnight, professor in the civil, environmental and architectural engineering department and a fellow in CU’s Institute of Arctic and Alpine Research.
In cases where ARD is linked directly with past and present mining activities it is called acid mine drainage, or AMD. Another Snake River tributary, Peru Creek, is largely devoid of life due to AMD generated from the abandoned Pennsylvania Mine and smaller mines upstream and has become a target for potential remediation efforts.
The Colorado Division of Reclamation Mining and Safety, in conjunction with other local, state and federal partners, is conducting underground exploration work at the mine to investigate the sources of heavy metals-laden water draining from the mine entrance. The new study by Todd and colleagues has important implications in such mine cleanup efforts because it suggests that establishing attainable cleanup objectives could be difficult if natural background metal concentrations are a “moving target.”
A study on the subject was published in the journal Environmental Science and Technology. Other collaborators include Andrew Manning and Philip Verplanck of USGS. The data analyzed for the study came from INSTAAR, the USGS and the U.S. Environmental Protection Agency.
