Press Release

To be published in June issue of Colorado Water

May 26, 2003
Contact: Dr. Jill Baron
Telephone: 970 491 1968
Email: jill@nrel.colostate.edu

CONFERENCE SUMMARY: ASSESSING THE IMPACTS OF PROLONGED SEVERE DROUGHT ON AQUATIC ECOSYSTEMS AND WATER QUALITY OF THE SOUTH PLATTE RIVER BASIN, COLORADO

During a drought, discussion usually centers on the lack of water, but there are obvious repercussions beyond those concerned with just the amount of water available. Two of these important repercussions were the focus of a recent conference: Assessing the Impacts of Prolonged Severe Drought On Aquatic Ecosystems and Water Quality Of the South Platte River Basin, Colorado. The conference was held April 3-4, 2003 at Colorado State University, and was sponsored by the EPA Office of Global Change.

Long-term and severe drought is a recurrent phenomenon in the western United States. In addition to the available historic data, paleoclimatic records show that low precipitation periods lasting 10-15 years have occurred surprisingly often over the past several hundred years. Thus, native riparian and aquatic plant and animal populations have evolved with high climate variability. Until recently, native freshwater populations have been able to find local refugia (springs, deep pools) during times of drought in order to persist. However, extensive damming, redistribution, and consumptive use by society has greatly reduced native habitats, and even dried up entire water bodies. The current drought has been especially hard on native and sport fisheries in Colorado.

The South Platte River Basin is the largest population center in Colorado, and supports a nationally important agricultural industry. Although the water originating in the mountains is relatively pure, downstream use has a large effect on water quality. Urban areas contribute nutrients, volatile organic carbon compounds, organochlorines, pharmaceuticals that can often function as endocrine disruptors, and PCBs while agricultural areas contribute nitrates, salinity, and sediments. River flow for nearly 100 km downstream of Denver is almost entirely wastewater effluent, except during spring runoff. In dry years these effluents become even more concentrated in surface waters, as there is less overall water for dilution.

These two topics engendered discussion among speakers, panel discussants, and the 100+ participants of the conference. The objectives of the conference organizers, Jill Baron (USGS and CSU) and Alan Covich (CSU), were to share scientific understanding of the consequences of severe drought, develop awareness and possibly preparedness for future drought, and build collaboration and trust among participants. Judging from the liveliness of the discussion and debate, the conference readily met its objectives.

A broad range of presentations explored direct and indirect effects of drought on species, ecosystems, and water quality, and the social and economic ramifications of drought to communities. A number of innovative planning and modeling tools were presented as ways to explore the consequences of different management approaches on municipal, agricultural, and environmental parameters. Several talks on managed groundwater recharge, termed “smart storage” by one speaker, were presented to illustrate innovative partnerships that can enhance instream flow, wildlife habitat, and water rights obligations.

Conference participants were reminded that drought exacerbates and accelerates problems associated with continued population growth. Drought also highlights flaws in water management, such as the direct connection between water supply and water quality that was overlooked in times of water abundance. Issues of current concern include the impact of tributary groundwater pumping on stream flows, the continued movement of water from agriculture to cities, the search for additional trans-basin diversions, the Big Straw, and growing pressure to pursue significant water conservation measures. Water quality and environmental issues are often considered as constraints limiting water development and management options, not as having value as sources of important environmental goods and services. Ultimately, the greatest environmental impact of drought may be in how it influences the political environment, and the long-term, statewide legacy of decisions made during periods of crisis. Communication and dialog among scientists and water managers, scholars and citizens, are essential to input to the debate over the future of Colorado’s water resources.