How to read this map
Every coloured line is a stretch of channel (about 200 m) that drains at least 0.25 km². Hover for its name; click to see why it ranks where it does, walk upstream or downstream, trace where its water goes, and log what you find there.
Main channels are labelled on the map. Every drain has a name in its hover label and panel; drains without a name on OpenStreetMap are named after the nearest neighbourhood, for example "Kalerwe drain 2".
Maintenance priority
The average percentile rank of six present-day pressures: runoff load (upstream area × paving), culverts and bridges, mapped dump sites and markets nearby, buildings within 15 m of the channel, buildings on low ground within 150 m, and how little wetland is left. Checked against 45 reported flood hotspots: AUC 0.73.
Emerging risk
Growth since 1990 in upstream paving and in building on the valley floor. Change measured in 1975–2000 predicted where valley floors were built over in 2000–2020 (AUC 0.79).
Work class
Urgent: high priority and still worsening. Fix now: high priority, stable. Coming: rising risk, not yet high. Watch: middle on both.
Field reports
Reports are shared with everyone who opens this page. They build the flood and blockage record that keeps the rankings honest.
Background map
Zoom in and the background switches to satellite imagery so you can see the actual channel, roofs and roads. Use the buttons in the legend to choose relief, satellite or street map yourself.
Sources
Channels, culverts, waste points, places: © OpenStreetMap contributors · buildings: Microsoft Global ML Building Footprints · built-up and population: JRC GHSL R2023A · relief: Copernicus GLO-30 DEM · wetland: ESA WorldCover 2021 · radar: ESA Copernicus Sentinel-1 · hotspots: KCCA/NEMA lists, news and local reports. Satellite imagery: Esri World Imagery (Esri, Maxar, Earthstar Geographics) · street map: © OpenStreetMap contributors. Analysis and tool: Gava Charles.