WEAP for adaptation planning: Water and climate resilience

The Water Evaluation and Adaptation Planning (WEAP) platform is a scenario-based modelling tool used in 190 countries to integrate supply- and demand-side perspectives for water resilience. It enables users to simulate climate-driven scenarios, evaluate adaptation strategies such as infrastructure upgrades and demand management, and analyze trade-offs at the water-energy-food nexus through integration with the Low Emissions Analysis Platform (LEAP) and macroeconomic models. WEAP supports both top-down and locally led initiatives across various scales, from local watersheds to transboundary river basins.

• WEAP is a scenario-based modelling tool with a 35-year history and over 50,000 users across 190 countries that allows for the analysis of climate change impacts on water availability and the evaluation of resource allocation choices regarding the economy, ecosystem health, and human well-being.
• The platform provides specific capabilities for National Adaptation Plan (NAP) development, including the use of climate projections for temperature and precipitation to simulate future groundwater levels, runoff, and water demand, as well as comparing strategies like ecological restoration and infrastructure upgrades.
• WEAP can be integrated with the Low Emissions Analysis Platform (LEAP) and macroeconomic modelling to analyze synergies and trade-offs within the water-energy-food nexus and their effects on economic growth.
• The tool has been applied in diverse geographic contexts, including modelling complex water systems in California, projecting water supply gaps in Rwanda, managing the Syr Darya and Amu Darya river basins in Central Asia, and developing adaptation strategies for the Upper Lempa River Basin spanning Guatemala, Honduras, and El Salvador.

APA

Davis, M., Huber-Lee, A., & Forni, L. (2025). WEAP for adaptation planning: Water and climate resilience. Stockholm Environment Institute. https://www.sei.org/wp-content/uploads/2025/11/weap-adaptation-planning-water-climate-resilience.pdf

Chicago

Davis, Marion, Annette Huber-Lee, and Laura Forni. WEAP for adaptation planning: Water and climate resilience. Stockholm Environment Institute, 2025. https://www.sei.org/wp-content/uploads/2025/11/weap-adaptation-planning-water-climate-resilience.pdf.

Wikipedia

{{cite report |last1=Davis |first1=Marion |last2=Huber-Lee |first2=Annette |last3=Forni |first3=Laura |title=WEAP for adaptation planning: Water and climate resilience |publisher=Stockholm Environment Institute |date=November 2025 |url=https://www.sei.org/wp-content/uploads/2025/11/weap-adaptation-planning-water-climate-resilience.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{davis2025weap, author = {Davis, Marion and Huber-Lee, Annette and Forni, Laura}, title = {{WEAP for adaptation planning: Water and climate resilience}}, institution = {Stockholm Environment Institute}, year = {2025}, month = nov, url = {https://www.sei.org/wp-content/uploads/2025/11/weap-adaptation-planning-water-climate-resilience.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }