The study, in press in the American Geophysical Union journal, Water Resources Research, looked at the effects of a range of reductions in Colorado River stream flow on future reservoir levels and the implications of different management strategies. Roughly 30 million people depend on the Colorado River -- which hosts more than a dozen dams along its 1,450 journey from Colorado's Rocky Mountains to the Gulf of California -- for drinking and irrigation water.
The Colorado River system is presently enduring its 10th year in a drought that began in 2000, said lead study author Balaji Rajagopalan, a CU-Boulder associate professor of civil, environmental and architectural engineering. Fortunately, the river system entered the drought with the reservoirs at approximately 95 percent of capacity. The reservoir system is presently at 59 percent of capacity, about the same as this time last year, said Rajagopalan, also a fellow at CU-Boulder's Cooperative Institute for Research in Environmental Sciences.
The research team examined the future vulnerability of the system to water supply variability coupled with projected changes in water demand. The team found that through 2026, the risk of fully depleting reservoir storage in any given year remains below 10 percent under any scenario of climate fluctuation or management alternative. During this period, the reservoir storage could even recover from its current low level, according to the researchers.
But if climate change results in a 10 percent reduction in the Colorado River's average stream flow as some recent studies predict, the chances of fully depleting reservoir storage will exceed 25 percent by 2057, according to the study. If climate change results in a 20 percent reduction, the chances of fully depleting reservoir storage will exceed 50 percent by 2057, Rajagopalan said.
"On average, drying caused by climate change would increase the risk of fully depleting reservoir storage by nearly ten times more than the risk we expect from population pressures alone," said Rajagopalan. "By mid-century this risk translates into a 50 percent chance in any given year of empty reservoirs, an enormous risk and huge water management challenge," he said.
But even under the most extensive drying scenario, threats to water supplies won't be felt immediately. "There's a tremendous storage capacity on the Colorado River that helps with the reliability of supply over periods of a just few years," said Rajagopalan.
Total storage capacity of reservoirs on the Colorado exceeds 60 million acre feet, almost 4 times the average annual flow on the river, and the two largest reservoirs -- Lake Mead and Lake Powell -- can store up to 50 million acre feet of water. As a result, the risk of full reservoir depletion will remain low through 2026, even with a 20 percent stream flow reduction induced by climate change, said Rajagopalan.
Between 2026 and 2057, the risks of fully depleting reservoir storage will increase seven-fold under the current management practices when compared with risks expected from population pressures alone. Implementing more aggressive management practices -- in which downstream releases are reduced during periods of reservoir shortages -- could lead to only a two-fold increase in risk of depleting all reservoir storage during this period, according to the study.
The magnitude of the risk will ultimately depend on the extent of climate drying and on the types of water management and conservation strategies established, according to the CU-Boulder study.
"Water conservation and relatively small pre-planned delivery shortages tied to declining reservoir levels can play a big part in reducing our risk," said Ken Nowak, a graduate student with CU-Boulder's Center for Advanced Decision Support for Water and Environmental Systems, or CADSWES, and a study co-author.
"But the more severe the drying with climate change, the more likely we will see shortages and perhaps empty reservoirs despite our best efforts." Nowak said. "The important thing is not to get lulled into a sense of safety or security with the near-term resiliency of the Colorado River basin water supply. If we do, we're in for a rude awakening."
"This study, along with others that predict future flow reductions in the Colorado River Basin, suggests that water managers should begin to re-think current water management practices during the next few years before the more serious effects of climate change appear," said Rajagopalan.
Titled "Water Supply Risk on the Colorado River: Can Management Mitigate?" the study was conducted with support from the Western Water Assessment – a joint venture of CU-Boulder and the National Oceanic and Atmospheric Administration, as well as CADSWES and the Bureau of Reclamation.
Other study authors included James Prairie of the Bureau of Reclamation, Martin Hoerling and Andrea Ray of NOAA, Joseph Barsugli and Bradley Udall of CIRES and Benjamin Harding of AMEC Earth & Environmental Inc. of Boulder.
ContactBalaji Rajagopalan, 303-492-5968
Balaji Rajagopalan | EurekAlert!
Joint research project on wastewater for reuse examines pond system in Namibia
19.12.2016 | Technische Universität Darmstadt
Scientists produce a new roadmap for guiding development & conservation in the Amazon
09.12.2016 | Wildlife Conservation Society
Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.
As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...
At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).
Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...
Many pathogens use certain sugar compounds from their host to help conceal themselves against the immune system. Scientists at the University of Bonn have now, in cooperation with researchers at the University of York in the United Kingdom, analyzed the dynamics of a bacterial molecule that is involved in this process. They demonstrate that the protein grabs onto the sugar molecule with a Pac Man-like chewing motion and holds it until it can be used. Their results could help design therapeutics that could make the protein poorer at grabbing and holding and hence compromise the pathogen in the host. The study has now been published in “Biophysical Journal”.
The cells of the mouth, nose and intestinal mucosa produce large quantities of a chemical called sialic acid. Many bacteria possess a special transport system...
UMD, NOAA collaboration demonstrates suitability of in-orbit datasets for weather satellite calibration
"Traffic and weather, together on the hour!" blasts your local radio station, while your smartphone knows the weather halfway across the world. A network of...
Fiber-reinforced plastics (FRP) are frequently used in the aeronautic and automobile industry. However, the repair of workpieces made of these composite materials is often less profitable than exchanging the part. In order to increase the lifetime of FRP parts and to make them more eco-efficient, the Laser Zentrum Hannover e.V. (LZH) and the Apodius GmbH want to combine a new measuring device for fiber layer orientation with an innovative laser-based repair process.
Defects in FRP pieces may be production or operation-related. Whether or not repair is cost-effective depends on the geometry of the defective area, the tools...
10.01.2017 | Event News
09.01.2017 | Event News
05.01.2017 | Event News
16.01.2017 | Power and Electrical Engineering
16.01.2017 | Information Technology
16.01.2017 | Power and Electrical Engineering