Watershed

Terrain and storms

Watershed is an educational terrain sandbox for PC built around real elevation data. You draw an area anywhere on Earth, choose a storm, and watch rain run through its valleys and toward the sea. Water flow is calculated on your graphics card, and the ground can fill with lakes or drain as you change the rainfall.

Six storm presets range from a desert cloudburst to a week-long monsoon, with each representing a real order of magnitude. You can also set the numbers yourself. Cloud shadows, rain and lightning appear over the terrain, while procedural sound follows the water.