Climate is changing. During the last century, the global average temperature increased 1.4F (IPCC, 2007). Changes in the form, amount, and intensity of precipitation have also been observed, although with significant regional variability (IPCC, 2007; Groisman 2005). Climate modeling experiments suggest these trends will likely continue or accelerate throughout the next century (IPCC, 2007; Karl et al., 2009). There is increasing concern about the potential effects of climate change on water resources. Potential effects of climate change include increased risk of flooding and drought, changes in the quality and seasonal timing of runoff, loss of aquatic habitat, and ecosystem impairment (Bates et al., 2008; Karl et al., 2009; U.S. EPA, 2008). Many communities, states, and the federal government are considering adaptation strategies for reducing the risk of harmful impacts resulting from climate change. Challenges remain, however, concerning how best to incorporate diverse, uncertain, and often conflicting information about future climate change into decision making. Despite continuing advances in our understanding of climate science and modeling, we currently have a limited ability to predict long-term (multidecadal) future climate at the local and regional scales needed by decision makers (Sarewitz et al., 2000). It is therefore not possible to know with certainty the future climatic conditions to which a particular region or water system will be exposed. Water resources in many areas are also vulnerable to increasing water demand, land-use change, and point-source discharges. Climate change will interact with these and other stressors in different settings in complex ways.