||Stratus Consulting, Inc., Boulder, CO.; Environmental Protection Agency, Washington, DC. Office of Water.; Environmental Protection Agency, Washington, DC. Office of Research and Development.
Climate change poses a variety of challenges for water management, and there is a need to develop methods for understanding and managing risk. While much has been written about the projected impacts of climate change at the continental or regional scale, scientists are quick to caution decision makers about using projections based on global circulation models (GCMs) for local decision making. This uncertainty. about specific impacts on local systems has raised concern about the ability of water resource managers to plan for climatic and hydrological changes at the local scale, and has spurred recent activity to develop methods for understanding vulnerabilities, including how to downscale climate models. This study examines and documents the steps taken by some of the leading utilities in an attempt to identify the emergent characteristics of water utility climate change vulnerability assessments. By examining the approaches taken and articulating the steps, information, and judgments needed for such decision making, we hope to contribute to the collaborative problem solving among the user and research communities who are working to further refine and validate such procedures. The study describes the activities of eight water utilities who have conducted climate vulnerability assessments: East Bay Municipal Utility District, City of Boulder Utilities Division, Denver Water, Massachusetts Water Resources Authority, New York City Department of Environmental Protection, Portland Water Bureau, Lower Colorado River Authority, and Seattle Public Utilities.