Access to safe water and sanitation is critical for public health and sustainable urban development, yet significant disparities persist in informal settlements across low- and middle-income countries. This study explores inequalities in WASH access within Korogocho and Viwandani which are two densely populated informal settlements in Nairobi, using a participatory geospatial approach. Community members collaborated in mapping key WASH-related assets, including water points, sanitation facilities, and waste collection sites, enabling a detailed spatial understanding often absent in official datasets.
A three-stage methodology was applied: participatory asset mapping, field validation using SurveyCTO , and data digitization and uploading onto OpenStreetMap. The process not only improved data quality but also empowered and built capacity of local residents through engagement in data collection and urban planning discussions.
Results revealed critical service gaps, facility unreliability, and infrastructure needs, particularly during droughts. Despite Nairobi’s reported high access levels to improved water (96.4%), this figure masks deep inequalities within its informal settlements. By identifying priority areas and visualizing spatial inequalities, participatory GIS offers a scalable model for inclusive planning and equitable WASH interventions. This research underscores the role of community-driven mapping in fostering sustainable urban resilience and informing policy for underserved populations.