Integrated water-energy-emissions analysis: Applying LEAP and WEAP together in California

The document argues that the 'nexus' of water, energy, and climate requires integrated modeling tools to avoid unwanted policy consequences. To address this, the Stockholm Environment Institute (SEI) linked its WEAP and LEAP systems. A California case study simulating the use of desalinated seawater to meet 5% of Southern California's urban water demand by 2049 found that while desalination could reduce water imports by approximately 300 million cubic meters per year in normal years, it would increase the water sector's electricity use by about 3 terawatt-hours and greenhouse gas emissions by 1.4 million tonnes of CO2e per year by 2049.

• The 'nexus' of climate, water, and energy is characterized by intricate links where decisions in one sector impact others; for example, biofuels increase irrigation demand, and hydraulic fracturing requires significant water supplies.
• SEI has integrated the Water Evaluation and Planning (WEAP) system and the Long-range Energy Alternatives Planning (LEAP) system to allow policy-makers to model evolving conditions and cross-sectoral impacts of policy choices.
• In California, the water sector accounts for 19% of total electricity consumption, with the State Water Project (SWP) being the largest single power consumer, using 3% of total electricity to pump roughly 4 billion m3 of water annually.
• California's Global Warming Solutions Act (AB32) targets reducing GHG emissions to 1990 levels (427 million tonnes of CO2e) by 2020, with electricity generation contributing about 24% of total emissions.
• A case study on meeting roughly 5% of Southern California's urban water demand with desalinated seawater through 2049 indicates that in normal years, water imports could be reduced by about 300 million cubic meters per year.
• The integrated analysis shows that by 2049, the use of desalination would increase the water sector's electricity consumption by approximately 3 terawatt-hours and increase emissions by 1.4 million tonnes of CO2e per year compared to a business-as-usual scenario.

APA

Stockholm Environment Institute (2012). Integrated water-energy-emissions analysis: Applying LEAP and WEAP together in California. https://leap.sei.org/documents\LEAPWEAPPolicyBrief2012.pdf

Chicago

Stockholm Environment Institute. Integrated water-energy-emissions analysis: Applying LEAP and WEAP together in California. 2012. https://leap.sei.org/documents\LEAPWEAPPolicyBrief2012.pdf.

Wikipedia

{{cite report |author=Stockholm Environment Institute |title=Integrated water-energy-emissions analysis: Applying LEAP and WEAP together in California |date=2012 |url=https://leap.sei.org/documents\LEAPWEAPPolicyBrief2012.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{stockholmenvironmentinstitute2012integrated, author = {{Stockholm Environment Institute}}, title = {{Integrated water-energy-emissions analysis: Applying LEAP and WEAP together in California}}, institution = {Stockholm Environment Institute}, year = {2012}, url = {https://leap.sei.org/documents\LEAPWEAPPolicyBrief2012.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }