The importance of infrastructure and national demand to represent constraints on water supply in the United States
James Rising, Laureline Josset, Tara J. Troy, Upmanu Lall
Abstract
Water stress in many regions is a consequence of precipitation that is spatially and temporally distant and the cumulative effects of withdrawals, inter-basin transfers, and reservoirs. Most maps of “water risk” do not account for the role of infrastructure and rely on local runoff metrics, which may be a poor proxy for experienced water stress. We present a new spatial and multi-sectoral optimization model of resource networks, applied here to water resources in the United States. The model, AWASH, includes a detailed representation of surface water and reservoirs, and relates water risk directly to failures to meet water demand as a function of climate. We find that considering the role of water conveyance and storage infrastructure in managing supply leads to a radically different picture of water risk, with substantial reductions due to both types of infrastructure – up to 60% reduction in risk due to conveyance and 38% due to storage. This highlights the importance of accounting of the role of infrastructure in national climate risk assessment and adaptation strategies.