Costs of repairing and expanding aging infrastructure and competing demands for water from other sectors such as industry and agriculture are stretching water managers' abilities to meet essential domestic drinking water needs for future generations. Using Bayesian statistical modeling on past and present water use, we project domestic water demand in the context of four climate scenarios developed by the Intergovernmental Panel on Climate Change as part of the their Special Report on Emission Scenarios (SRES). We compare 2010 demand to projections of domestic water demand for the years 2030, 2060 and 2090 for the four SRES scenarios. Results indicate that the number of counties exceeding fifty percent or greater demand over 2010 levels increases through 2090 for two of the scenarios and plateaus around 2050 for the other two. Counties experiencing the largest increases in water demand are concentrated in the states of California, Texas, and isolated portions of the Mid-West, Southeast, and Mid-Atlantic. Closer examination of the spatial distribution of high demand counties reveals that they are typically found near or adjacent to metropolitan centers, potentially placing greater stress on already taxed systems. Identifying these counties allows for targeted adaptive management and policies, economic incentives, and legislation to be focused towards locations that are potentially the most vulnerable.
Keywords: Climate; Resilience; Sustainability; Water demand.