Water

Water is a fluid block which flows quickly. It cannot be legitimately obtained in game, but can be found naturally.

Generation
Water generates at sea level around the edges of the map, and can sometimes be found inland in small ponds and lakes. Sometimes, if the terrain is low enough, larger portions of the map can be submerged under water. Caves can also sometimes be flooded if they are exposed to water through a cliff face.

Behaviour
When Water is not flowing, it uses the still block ID. In this form, the block is not ticked, and remains dormant until it receives a block update and finds an empty space to flow into. The block will then convert to the flowing block ID.

In the flowing form, Water is ticked periodically every 4 ticks. Each tick, it will attempt to flow into any empty spaces around it. If no empty spaces are found, the block will revert to the still block ID.