**UNOSAT code: FL20240603LKA, GDACS ID: 1102660** This map illustrates satellite-detected water extent in Gampaha, Colombo and Kalutara Districts, Western Province, Sri Lanka as observed from a Sentinel-1 image acquired on 04 June 2024 at 00:25 UTC. Within the analysed areas of about 8,000 km², a total of about 124 km² of lands appear to be affected with flood waters. Based on WorldPop population data and the flood extent about 100,000 people are potentially exposed. This is a preliminary analysis and has not yet been validated in the field. Please send ground feedback to the United Nations Satellite Centre (UNOSAT). Important note: Flood analysis from radar images may underestimate the presence of standing waters in built-up areas and densely vegetated areas due to backscattering properties of the radar signal.