As agricultural landscapes urbanize throughout the United States, aquatic systems degrade. Impervious surfaces such as roofs, streets and sidewalks cause fundamental changes in watershed hydrology. These surfaces increase runoff peaks and volumes and decrease water quality and groundwater levels. Soil and nutrient runoff erodes channels and degrades habitats by causing sedimentation and eutrophication of lakes and wetlands.

Diminished groundwater levels, in turn, desiccate wetlands and reduce high-quality groundwater flow to springs, streams and lakes. Consequently, wetland biodiversity declines. Regions that pump groundwater for domestic use and irrigation exacerbate these hydrologic and ecological effects.

The North Fork of the Pheasant Branch Conservancy near Madison is an ideal subject for an interdisciplinary research effort to learn about these effects and develop analytical and modeling tools to minimize them. Civil and Environmental Engineering Professor Kenneth Potter (back row, second from right) and Center for Limnology Researcher Richard Lathrop (back row, third from left) are co-principal investigators on the study, which includes scientists from UW-Madison and the Wisconsin Department of Natural Resources.

Considering a range of urban development issues, including storm runoff, groundwater depletion, wastewater treatment, nuisance algae growth and wetland degradation, the team is evaluating alternative management practices and urbanization patterns. In addition, researchers also examining how these issues are interrelated and the social and political opportunities for, and constraints on, effective management.

Photo by Bruce Fritz