The Ushahidi platform is an open-source software tool designed to collect, visualize, and analyze crowdsourced data from multiple sources to create customizable maps and timelines, making it easy to track, organize, and present information. Its adaptability makes it valuable for applications such as disaster response, human rights monitoring, community engagement, and civic participation. The platform's strength lies in its ability to democratize data collection and empower communities to tell their own stories.  The UNDP Indonesia Accelerator Lab, in collaboration with the National Land Agency’s project office (PMO Jabodetabekpunjur) and OpenStreetMap (OSM) Indonesia Association, utilised the Ushahidi Platform for the lake mapping initiative in the Jabodetabek area to assess the flood mitigation potential of natural and artificial lakes while promoting citizen participation in decision-making processes. From March to July 2022, participatory data collection was conducted using open-source technologies, including OpenStreetMap satellite imagery and qualitative surveys. In total, data from 170 lakes in the Jabodetabek area were collected through a crowdsourcing platform, making the information publicly accessible.