Integrated decision support for energy/water planning in California and the Southwest

Policy makers and resource managers need to understand the interconnections between energy and water use and production -- the energy-water nexus -- to make well-informed decisions regarding long-term system planning. Planning and assessment issues include the development of strategies for reducing the vulnerabilities of water and energy systems to climate change while also reducing greenhouse gas emissions. To provide useful decision support for climate adaptation policy and planning, it is important to understand the regionally-specific characteristics of the energy-water nexus, and the history of the current water and energy supply systems serving an area. This will help decision makers understand the extent to which past choices have determined the nature of current adaptive capacity, and how those choices may have reduced certain vulnerabilities, while perhaps increasing others. We present an integrated water/energy modeling platform that can facilitate tailored water-energy analyses based on a detailed representation of local conditions. The modeling platform entails linking the Water Evaluation and Planning (WEAP) integrated water management modeling system with the Long Range Energy Alternatives Planning (LEAP) system to create fully-coupled modeling capabilities. This will allow analysts to consider feedbacks between energy system development and changes in water policy or infrastructure in order to better represent the long-term consequences of decision-making in either sector. Preliminary results are presented from an effort to create this coupled modeling system for the U.S. Southwest and California. This region is marked by large-scale regional integration of both the electric power and water sectors. The linkages between water and energy planning and policy questions in this region are described along with early insights from applications of the coupled modeling system.