Pumps & sources
100%
TrickleTorrent
The pump tool links two points: first click drinks, second click pours. Faucets add water, drains take it away.
Thermodynamics
Water freezes at 0° and boils at 100°. Steam rises, cools, and rains back down.
Ice holds its shape until something warms it — try freezing a waterfall mid-air.