Introducing the WASH Flows analytical tool

The Stockholm Environment Institute has introduced WASH Flows, a Microsoft Excel-based analytical tool that integrates household-level water, sanitation, and hygiene (WASH) data with watershed-scale hydrological modelling. By linking these traditionally siloed disciplines, the tool allows users to estimate service baselines, identify community vulnerabilities, and model the impact of interventions on water quality and availability. A case study in the Tupiza watershed, Bolivia, demonstrated the tool's ability to identify critical gaps in safely managed water and sanitation and to propose infrastructure solutions that enhance community resilience to drought.

• The WASH Flows tool is designed to bridge the gap between watershed management and water, sanitation, and hygiene (WASH) services, which have traditionally been governed in silos. It connects household-level WASH data with watershed-scale flows to allow for an integrated analysis of water security.
• Operating within a Microsoft Excel interface, WASH Flows can estimate wastewater generation, water demand, and WASH service levels based on household infrastructure. It can be used as a standalone tool or coupled with watershed-scale modelling tools like WEAP (Water Evaluation and Planning) to analyze the reliability of water sources and the impact of wastewater on downstream water bodies.
• In a case study of the Tupiza watershed in Bolivia, the tool identified significant WASH service deficiencies in rural areas: only 25% of households had access to safely managed water services, 4% had safely managed sanitation, and 22% of rural communities had access to basic hygiene services.
• The Tupiza case study used WASH Flows to estimate that wastewater discharge from rural communities resulted in a biological oxygen demand (BOD) ranging from 10 to 15 kg per inhabitant per day.
• By coupling WASH Flows with climatic data in the WEAP Tupiza model, researchers identified six communities lacking water access during drought periods. The model suggested that implementing community drinking water systems (such as rainwater harvesting tanks and wells) and decentralized sanitation systems (such as artificial wetlands and urine-diverting dry toilets) could reduce water-access vulnerability and increase drought resilience.
• The tool's outputs were validated through a two-stage process: first, by comparing the calculated service baseline against national census data, and second, through 'ground truthing' visits to communities to gather data on topography and existing infrastructure to verify proposed technical solutions.

APA

Claure, P., Esquivel, N. N., Liera, C., Trujillo, A. S., & Escobar, M. (2023). Introducing the WASH Flows analytical tool. Stockholm Environment Institute. https://www.sei.org/wp-content/uploads/2023/02/wash-flows-watershed-management-tool.pdf

Chicago

Claure, Pamela, Nhilce N. Esquivel, Carla Liera, Adriana Soto Trujillo, and Marisa Escobar. Introducing the WASH Flows analytical tool. Stockholm Environment Institute, 2023. https://www.sei.org/wp-content/uploads/2023/02/wash-flows-watershed-management-tool.pdf.

Wikipedia

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BibTeX

@techreport{claure2023introducing, author = {Claure, Pamela and Esquivel, Nhilce N. and Liera, Carla and Trujillo, Adriana Soto and Escobar, Marisa}, title = {{Introducing the WASH Flows analytical tool}}, institution = {Stockholm Environment Institute}, year = {2023}, month = feb, url = {https://www.sei.org/wp-content/uploads/2023/02/wash-flows-watershed-management-tool.pdf}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }