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OCTOBER 2, 2012

BOULDER, COLORADO – Where does our water come from and how does climate change affect its future availability? In the arid West, mountain snowpack holds the answers to these and other questions.

Mark Williams, professor of geography and fellow at the Institute of Arctic and Alpine Research (INSTAAR), is an expert in snow hydrology and mountain ecology. He studies the storage and release of water from snowpack into mountain streams and what percentage of that water ultimately makes its way into homes. As principal investigator of the Niwot Ridge Long-Term Ecological Research program at CU-Boulder’s Mountain Research Station, Williams and his team also explore the impacts of climate change, groundwater storage and pollution. The National Science Foundation funds the Niwot Ridge Long-Term Ecological Research project, located above 10,000 feet in the mountains near Boulder.

This team’s research is highlighted in a new five-minute educational video titled, “Water: A Zero Sum Game” viewable at In a one-of-a-kind underground and under snow laboratory, the researchers use an array of lysimeters that isolate, collect and measure snowmelt. These data are important for people downstream.

“Snow accumulates in the winter. It’s kind of like a bank where you have this nice capital account,” says Williams, who estimates that between 60 and 90 percent of all usable water in the western United States comes from snowmelt runoff.

Unfortunately, warming temperatures have resulted in less snow and shorter winters in recent years. In fact, the 2012 snowpack at Niwot Ridge was roughly half of normal and snowmelt began one month before average.
“If we switch from snow to rain because it’s warmer, we’re going end up with less usable water because we’re going to lose that banking effect we get from the seasonal snowpack,” Williams says. “And we’re going to lose more water to evapotranspiration.”

This is of particular concern to the southwestern United States as dry places get drier simply because they heat up faster, he says.

[“Water: A Zero Sum Game” is the latest in a series of videos hosted at The Learn More About Climate initiative localizes climate change for Coloradans, offering web resources, current research, educational videos, educator tools and more. The website also features a video titled “A Hotter, Drier Colorado” that focuses on how climate change is affecting Colorado’s water supply.]

The Long-Term Ecological Research (LTER) program was created in 1980 by the National Science Foundation to conduct research on ecological issues that can last decades and span huge geographical areas. The network brings together a multi-disciplinary group of more than 2,000 scientists and graduate students. The 26 LTER sites encompass diverse ecosystems in the continental United States, Alaska, Antarctica, and islands in the Caribbean and the Pacific—including deserts, estuaries, lakes, oceans, coral reefs, prairies, forests, alpine and Arctic tundra, urban areas, and production agriculture.