The weight of current evidence suggests that climate change is occurring and will continue to occur in the foreseeable future. The rate and intensity of change is not immediately known; however, the impacts can already be observed in changes to the quality of drinking water utility source waters. Climate change models, in general, predict an overall warming of the earth. The warmer temperatures associated with climate change are predicted to decrease dissolved oxygen levels, increase contaminant load to water bodies, reduce stream and river flows, foster algal blooms, and increase the likelihood of saltwater intrusion near coastal regions. Climate change impacts to water quality are occurring over a very dynamic range. The wide variability of impacts is illustrated by regions in the United States such as the southeast, which experienced record drought, and the northeast, which experienced record snowfalls. All of these climate change impacts play a role in water quality and have implications for water, wastewater, and stormwater utilities. The need is pressing for utilities to address changing water qualities, and this will require fundamental changes in utility operations.