The OpenCities Dominica project addresses the lack of flood data to enhance resilience planning on the island. Through community-based mapping using mobile phones, 260 building footprints were updated in OpenStreetMap, and 24 essential maps were created. This effort has fostered a culture of open data use, strengthening disaster preparedness. Dominica emerges as a leader in adapting to climate threats, demonstrating the effectiveness of mobile mapping for community resilience and sustainable development.