An interactive 3D model of how rainfall, river levels, sea level rise, and drainage combine to flood a city. Adjust the controls and watch the water rise.
📘 Learn: Why cities flood ▾
Rainfall that exceeds what soil and drains can absorb pools on streets and low ground — this is urban flooding.
Drainage efficiency represents storm drains, canals, and pumps. Aging or blocked drains lose efficiency, making the same rainfall much worse.
River level rises after heavy rain upstream. Land near riverbanks (the floodplain) is flooded first and worst.
Sea level rise permanently raises the baseline water table for coastal cities — even "sunny day flooding" grows more common over decades.
Just 15–30 cm of fast-moving water can float a car. 60 cm can move most vehicles entirely.
Higher elevation = lower risk. City planners use zoning to keep critical buildings (hospitals, shelters) on higher ground.
Combining factors compounds risk: a high river level plus heavy rain plus poor drainage is how the worst urban floods happen.
Flood Controls
🌧️ Rainfall 20 mm/h
Precipitation intensity. Heavy, sustained rain overwhelms drainage and pools water city-wide.
🏞️ River Level 10%
Upstream flow intensity. Raises water along the river channel and its floodplain first.