Water
Water could not be found in Module:ItemData.
Types
In ECO there is fresh water and salt water.
The game tracks the spread of salt water through terrain. Most plants have a limited tolerance for salt in the soil and will suffer if the salt water spread is to great. Destruction of beach terrain hastens the spread of salt water through terrain even if the water doesn't visibly spread.
Salt water that comes into contact with other biomes at high enough levels will cause the previous biome to change to ocean biome. Dirt in the new ocean biome will transform to Ocean Sand texture. Currently there is no known way to revert biomes changed to ocean, and is most commonly experienced alongside rises in sea level. Rises in sea level will also cause fresh water lakes and streams to become 'contaminated' with salt water changing the flora and fauna, this will also contribute to salt water spread.
The effects on e.g. farming is yet widely unknown and remains to be tested.(Note: Farming near a water source ie: river, will cause the water to turn brown, effects came after constant working with the land near water
Physics
It is possible for the player to fire bows and use tools underwater, as well as mine at blocks when submerged.
Blocks such as dirt and stone can be used to 'exclude' water from an area that has been flooded.