The wetlands in the Congo Basin store and release water, affecting carbon and nutrient transport. This study used remote sensing and modeling to track water sources and sinks. Rain and runoff are the main water sources, while river-wetland exchanges play a significant role in water storage during peak season. River-wetland exchanges also contribute a large portion of water outputs, with evaporation accounting for the rest. Overall, the Congo wetlands receive water from the river during peak storage season and supply water back to the river throughout the year.