Unseen Colorado Mountain Aquifers Throw Water on 'Teflon Basin' Myth

Image: A researcher investigates the snowpack at the Niwot Ridge Long-Term Ecological Research (LTER) site. Credit: Niwot Ridge LTER site

Scientist Mark Williams of the University of Colorado at Boulder conducted geochemical studies that show that less than half of the annual snow melt in the Green Lakes Valley in the mountains west of Boulder arrives at a downstream watershed treatment facility as "new water." He found that most of the water sampled from North Boulder Creek during runoff months was "old groundwater" that had been stored in subterranean mountain catchments.

"We're seeing that snow melt is re-charging the hydrologic systems in the mountains, pushing old groundwater from subsurface reservoirs into rivers and streams," Williams said. "The common perception that water stored in mountain snow packs runs immediately into streams and rivers is probably wrong, and the Teflon basin myth is incorrect."

Groundwater in the Green Lakes Valley on Niwot Ridge -- a National Science Foundation (NSF)-funded Long Term Ecological Research (LTER) site -- appears to be stored in a huge catacomb of rock that Williams likened to a tiered cake. Researchers sampled surface snow and rain as well as streams, lakes and springs in the area, at tree line and above.

Similar studies by Williams and colleagues near Leadville, Colo., showed that high-mountain groundwater is dominated by snow melt that is locked underground for years or decades. Water from the snow pack replenishes high-altitude groundwater reservoirs, pooling underground rather than rushing downstream toward the plains.

"A greater understanding of how human activities impact the water in our aquifers, streams and rivers is critical," says Henry Gholz, director of NSF's LTER program. "This research demonstrates how wrong our simplifications can be."

The many fault and fracture zones in the Rocky Mountains are the primary portals to the hidden catchments, he said. But the complex geology overlying the mountain aquifers continues to challenge researchers.

"The significant delay between the time we saw water entering the system at the top end and the time it showed up in the creeks was surprising," Williams said.

The researchers found that just before the peak spring runoff, more than 50 percent of the flow in North Boulder Creek above tree line was old groundwater. During the weeks immediately following the peak runoff flow, the amount of aging groundwater in the creek jumped to roughly 80 percent, he said.

"But we don't yet know how connected high-mountain groundwater is to the large, well-known aquifers on the eastern plains," Williams said. "We need to investigate this possible connection."

Source: NSF

OSU Scientist Uses Fiber Optics to Measure Water and Air
Scientists at Oregon State University are using fiber optics to study the temperature of water, the flow of air, and the dynamics of snow melt.
Slow melt of heavy snow better for the environment
Water is on the minds of many Canadians at the moment, and not just because this Saturday is World Water Day. The record level accumulation of snow laden with imported moisture brought up from the Gulf of Mexico has resulted in snow packed with water: This kind of snow takes longer to melt than the usual lake effect, dry, fluffy snow typically seen around southern Ontario.
Melting snow provides clues for acidification
In forests of the northeastern United States, sulfate and nitrate are the dominant dissolved forms of sulfur and nitrogen in precipitation. In winter, these acidic agents accumulate in the snowpack and are released to groundwater and streams over a short period of time during spring snowmelt. This pulsed release of sulfate and nitrate in snowmelt can cause episodic acidification in poorly buffered soils, ultimately threatening the health of acid-sensitive biota.
High temperatures, low precipitation creating many problems
The hot, dry conditions in Indiana may have one bright spot - creating a more fiery display of fall leaves in some parts of the state. But that's not much solace for farmers, gardeners, boaters and fishermen plagued by a weather system that shows no signs of dissipating soon.
US needs to plan for climate change-induced summer droughts
The western United States has experienced increasing drought conditions in recent years – and conditions may worsen if global climate change models are accurate – yet the country is doing little to prepare for potential catastrophe, a group of scientists said today.
NASA Outlines Recent Changes in Earth's Freshwater Distribution
Recent space observations of freshwater storage by the Gravity Recovery and Climate Experiment (GRACE) are providing a new picture of how Earth's most precious natural resource is distributed globally and how it is changing.
Evolving designer ecosystem sheds light on unintended consequences
Amidst the semi-arid stretches of Phoenix, a visitor might blink twice at the sight of a sailboat cutting across the horizon. Tempe Town Lake, on the northern edge of Arizona State University (ASU), is just one of a multitude of lakes, small ponds, canals and dams combining flood control, water delivery, recreational opportunities and aesthetics, and altering perception of water availability and economics in the area.
Thawing permafrost likely to boost global warming
The thawing of permafrost in northern latitudes, which greatly increases microbial decomposition of carbon compounds in soil, will dominate other effects of warming in the region and could become a major force promoting the release of carbon dioxide and thus further warming, according to a new assessment in the September 2008 issue of BioScience.

Unseen Colorado Mountain Aquifers Throw Water on 'Teflon Basin' Myth

Related stories:

News discussion: