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 climate 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 book 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.