Cleaning the Water Supply under Alternative Climate and Land Use Scenarios in a typical Midwest watershed

There is a critical need for improved understanding of how the integrated effects of climate change and land use will affect regional water quality and water treatment costs. Climate change directly affects the hydrological cycle and water resources either positively or negatively, depending on the region and patterns of land and water use. Future climate change trajectories will lead to changes in land use among forests, urban areas, and agricultural lands which will affect aquatic water quality and water treatment costs. In the Midwest, intense land and water use for agriculture releases contaminants into water bodies and increases water treatment costs necessary to safeguard human and aquatic life. Source water protection can be a very efficient way to reduce water treatment cost. In Indiana's Upper White River Watershed, intensive agriculture has impaired water bodies; this situation will worsen with population growth, climate change, and land use change. Current water protection programs lack sufficient long-term quantitative scientific guidance to improve watershed protection efficiencies. While many studies on water conservation are qualitative and practical, very few analytical studies have integrated long-term climate change, water quality, and treatment costs to inform watershed protection strategies.

In this study, we integrate long-term climate change and land use change dataset, the InVEST Water Purification modeling framework, field experimentation, and local stakeholder engagement to examine the interaction of climate change, land use, water purification, and treatment costs in the Upper White River Watershed. The outcome will advance the study of watershed protection that integrates complex social and biophysical processes, inform and guide conservation practices by revealing areas that most effectively clean the water supply under future climate change scenarios. The approach will be beneficial to local community and is easily applied to other regions.