Water on the move

Dam Break

Open a breach in the wall and follow the flood wave through the valley.

100%reservoir remaining

0.0peak flow · units/s

The dam is holding

Reservoir Breach width

Changing either setting refills the reservoir and repairs the dam.

Ground resistance Medium

View

Darker blue means deeper water.

Show flow streaks

Try a wide breach at ¼×. The striped posts are two units tall. Drag to orbit · Scroll to zoom.

body > main { display: none; }.simulation-fallback { max-width: 720px; margin: auto; padding: 24px; line-height: 1.6; }.simulation-fallback img { width: 100%; height: auto; }← Explore all worlds

Dam Break

Breach a dam and follow the flood wave into the valley. Compare reservoir levels, opening widths, and the resistance of the ground.

Blue water rushing through a gap in a concrete dam and spreading down a green valley with pine trees and striped depth posts.

Enable JavaScript in a browser with WebGL 2 to run this interactive simulation.

A dam holds water above the valley below. When a gap opens, the difference in water level drives a flood through it.

The reservoir stays still behind the intact wall. Breaking the dam opens a gap and sends water downhill.
A wider breach lets more water through at once. A higher reservoir can produce a stronger release.
The flood spreads into low ground and slows as it spreads out. Rougher ground resists the flow more.
Water leaving the far end of the valley keeps flowing downstream. The trees and striped depth posts provide scale without blocking the flood.

Try this: Break the dam at ¼×, then restart with a wider breach and compare the peak flow. Darker water is deeper; Flow speed makes fast water pale. This is an illustrative model, not a flood forecast.