WEAP: water evaluation and adaptation planning

WEAP is a comprehensive software tool for integrated water resources planning used by over 50,000 users in nearly 200 countries. It functions as a database, forecasting tool, and policy analysis system that balances water demand—including use patterns and allocation—with supply factors like streamflow and groundwater. The software features a GIS-based graphical interface and supports scenario-based analysis to evaluate the impacts of climate change, demographic shifts, and policy changes on water systems. It has been applied in diverse global contexts, including projects in China, Rwanda, Colombia, India, Nepal, and California, to support stakeholder dialogue and evaluate environmental flows.

• WEAP is an integrated water resources planning tool used by more than 50,000 users across nearly 200 countries and has informed over 1,000 publications globally.
• The software operates as a database for maintaining supply and demand information, a forecasting tool for simulating runoff, pollution, and water quality, and a policy analysis tool to evaluate management options and competing water uses.
• Scenario analysis is a central feature of WEAP, allowing users to model the effects of climate change on demand and supply, rising CO2 levels on crop yields, and changes in demographic or economic patterns.
• The tool utilizes a GIS-based graphical interface and incorporates CMIP6 climate scenarios and built-in databases for elevation and land cover to streamline model-building.
• WEAP has been applied to specific regional challenges, such as evaluating climate and land use impacts on river flooding in Colombia, supporting multi-stakeholder dialogue in China, and exploring water conservation in India and Nepal.

APA

Stockholm Environment Institute (2025). WEAP: water evaluation and adaptation planning. https://www.sei.org/wp-content/uploads/2023/03/weap-factsheet-2025.pdf

Chicago

Stockholm Environment Institute. WEAP: water evaluation and adaptation planning. 2025. https://www.sei.org/wp-content/uploads/2023/03/weap-factsheet-2025.pdf.

Wikipedia

{{cite report |author=Stockholm Environment Institute |title=WEAP: water evaluation and adaptation planning |date=August 2025 |url=https://www.sei.org/wp-content/uploads/2023/03/weap-factsheet-2025.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{stockholmenvironmentinstitute2025weap, author = {{Stockholm Environment Institute}}, title = {{WEAP: water evaluation and adaptation planning}}, institution = {Stockholm Environment Institute}, year = {2025}, month = aug, url = {https://www.sei.org/wp-content/uploads/2023/03/weap-factsheet-2025.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }