New WEAP PlugIn calculates water stress, disaggregated by sub-basin

The Stockholm Environment Institute and the FAO have developed a WEAP PlugIn that allows for the calculation of water stress at the sub-basin level rather than just on a country-wide basis. By disaggregating data, water resource managers can better visualize spatial variations in water stress and test the impact of different management strategies, such as reducing canal losses or accounting for population growth. The tool uses the Flow Duration Curve (FDC) Shift method to incorporate environmental flow requirements into its calculations. The briefing demonstrates the tool's application using the Senegal River basin and lists recommendations for its implementation in other basins.

• A new PlugIn for the Water Evaluation and Planning (WEAP) software, developed by the Food and Agriculture Organization of the United Nations (FAO) and the Stockholm Environment Institute (SEI), enables the calculation of water stress by catchment area to provide detailed insights at the sub-basin level.
• The tool calculates water stress based on SDG Indicator 6.4.2, which compares total freshwater withdrawals (TFWW) against total renewable freshwater resources (TRWR) after subtracting environmental flow requirements (EFR).
• To standardize calculations where minimum environmental flows are not established, the PlugIn utilizes the Flow Duration Curve (FDC) Shift method, which adjusts requirements based on the ecological management class of the river.
• Application of the tool to the Senegal River basin demonstrates that water stress varies significantly by sub-basin; for example, in 2021, water stress was below 10% in the upstream Bakoye, Kolombine, Faleme and Karakoro basins, but exceeded 70% in the lower portions of the Senegal River below Bakel.
• Simulations in the Senegal River basin indicate that reducing canal losses from an average of 35% to 15% leads to a clear decrease in water stress.
• The tool can project the impact of future uncertainties; for the Senegal River basin, a high population growth scenario (4% per year) is projected to increase water stress and decrease water demand satisfaction, particularly for Dakar.
• Based on testing in Algeria, Rwanda, and the Senegal River basin, the developers recommend that models for disaggregated water stress should cover entire basins, include all significant external water supplies and demands, and avoid selecting small catchments unless they are major freshwater sources.

APA

Joyce, B., & Salazar, D. (2023). New WEAP PlugIn calculates water stress, disaggregated by sub-basin. Stockholm Environment Institute. https://www.sei.org/wp-content/uploads/2023/12/sei2023.062-weap-plugin-water-stress-corrected.pdf

Chicago

Joyce, Brian, and Doreen Salazar. New WEAP PlugIn calculates water stress, disaggregated by sub-basin. Stockholm Environment Institute, 2023. https://www.sei.org/wp-content/uploads/2023/12/sei2023.062-weap-plugin-water-stress-corrected.pdf.

Wikipedia

{{cite report |last1=Joyce |first1=Brian |last2=Salazar |first2=Doreen |title=New WEAP PlugIn calculates water stress, disaggregated by sub-basin |publisher=Stockholm Environment Institute |date=December 2023 |url=https://www.sei.org/wp-content/uploads/2023/12/sei2023.062-weap-plugin-water-stress-corrected.pdf |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{joyce2023new, author = {Joyce, Brian and Salazar, Doreen}, title = {{New WEAP PlugIn calculates water stress, disaggregated by sub-basin}}, institution = {Stockholm Environment Institute}, year = {2023}, month = dec, url = {https://www.sei.org/wp-content/uploads/2023/12/sei2023.062-weap-plugin-water-stress-corrected.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }