Discover where water flows from towns around the world with Downstream, a constantly changing river and water flow map for your TRMNL.

Every 15 minutes, Downstream picks a different town and follows the path a raindrop would take from there, stream by stream and river by river. See the entire route on a map, from the starting stream to its final destination: a sea, lake, or sometimes somewhere underground.

The map shows every named stream, river, and lake along the journey, together with the total distance and a rough estimate of how long the water takes to travel. Some routes are only a few kilometres long. Others cross entire countries and travel thousands of kilometres before reaching the sea.

River network: HydroATLAS (Linke et al. 2019; Lehner & Grill 2013) and lake residence times: HydroLAKES (Messager et al. 2016), both CC BY 4.0, simplified. Towns: GeoNames (CC BY 4.0). Stream, river and lake names and the map: © OpenStreetMap contributors (ODbL). Seas: Natural Earth. Dams, canals and city drains are not modelled.