Published: May 12, 2002

Drought has most Coloradans focused on the increased risk of fire hazard, but scientists at CU-Boulder and NOAA have additional concerns about the risks to water quality as the summer heats up.

"The threats that drought represents to aquatic organisms include loss of habitat and alterations to the quality of the remaining habitat," said Jim Saunders.

Saunders is associate director of the Center for Limnology at the Cooperative Institute for Research in Environmental Sciences on the Boulder campus. CIRES is a joint institute of the University of Colorado at Boulder and the National Oceanic and Atmospheric Administration.Ìý

"Drought undermines an important facet of regulatory protection of aquatic life by reducing the amount of water available for diluting pollutants and by slowing the flow of the water," Saunders said. "Drought also increases summer stream temperatures - at low flows, streams heat up more during the day."

"Since one of the most prominent influences on water quality is the discharge of treated wastewater, with reduced flow, concentrations of pollutants in surface waters also increase," he said. "Heat and increased pollutants are both reasons that threats to aquatic organisms can mount during drought." A recent fish kill in a small lake in Boulder has been attributed to the drought.

Saunders is involved in CIRES' Western Water Assessment, a four-year-old study that assesses regional climate within local social, economic and environmental contexts. For the project, Saunders has been modeling the South Platte River basin -- an area that includes Denver -- where stream flow is currently at about 50 percent of normal.Ìý

Supported at CU-Boulder by the NOAA Office of Global Programs, the Western Water Assessment is only one of several Regional Integrated Science Assessment groups nationwide that reflect a new, localized approach to understanding the impacts and identifying responses to climate extremes, according to Martyn Clark, project leader.

"The regional studies involve environmental and social scientists, legal specialists, hydrologists and climatologists," Clark said. At CU-Boulder, CIRES scientists partner with the NOAA Climate Diagnostics Center and CU's Natural Resources Law Center in evaluating both the environment and decision-making processes governing water use in seven states.

"The work is designed to help natural resources managers make better decisions," Clark said.