40d:Water

Water is a fluid found all over the world. It flows from mountain springs, forming the world's oceans, lakes, rivers, and brooks. Water falls as rain and snow, and freezes into ice. Water is home to aquatic creatures. Most creatures can swim in deep water, and like all fluids, air-breathing creatures can drown in it. Water comes in two varieties: freshwater, which makes up almost all inland water, and saltwater, which fills the seas; these are home to different aquatic creatures. Injured dwarves will only drink freshwater, though normally dwarves prefer their booze.

In addition, water can be stagnant or murky. This may cause dwarves to have unhappy thoughts if they drink from it.

When water comes into contact with creatures and objects, they become "contaminated" with it. Soil and stone becomes damp or muddy, which can be used for farming.

Water is displayed with the symbols ≈ and ~, sometimes with different blues, brown, and white to show ripples, pollutants and flow. (The game can be configured to show the depth instead). Dark-colored water symbols indicate the water is one Z-level below the camera level. Water has 7 depth levels per tile, with 1 being perhaps ankle-deep, and 7 filling the tile completely. Dwarves and other humanoids can walk through water up to depth 4. At 4 they can choose to walk or swim, any deeper and they must swim to pass through the tile.

Every material sinks in water.^{v0.27.169.33a}

The tiles above brooks are treated as floor tiles. They are passable to creatures, and objects do not fall into them.

Water in Fortress Mode

In addition to drinking, pools and rivers can be used for fishing. To specify a pool of water as a water source, fishing zone, or pond, you need to create activity zones at the level above the water. The "level above the water" is the level at which the surface of the water is at foot-level instead of ceiling level. Water can be bridged, and can also be used to make a moat.

Water can be moved by digging channels or tunnels, using buckets, or by constructing a screw pump. Dwarves will use buckets to fill a pond. Screw pumps (operated by dwarf or machine power) can move water vertically and horizontally.

Lakes can be drained by digging into the side of them. Rivers can also be redirected in this manner. It is not possible to dig directly up into a water-filled tile, however.^{v0.27.169.33a} Fish and other aquatic creatures will stay in the water as it moves, but may end up on the ground if the water becomes too shallow. Drained lakes that are outside are filled by melting ice and snow, but not by rain.

Tiles adjacent to a water-filled tile are labeled "damp" and flash the water symbol when accessing the designations menu. When a miner discovers a damp tile, he cancels the mining designation, the game pauses, and the camera centers on the tile. This happens for every damp tile discovered, and each must be designated again before a miner will dig it out.^{v0.27.169.33a} Digging under a water-filled tile does not actually drain it, even though you receive multiple warnings about damp tiles.

Water wheels can be used to generate mechanical power from flows.

Water in Adventurer Mode

Water preference, when possible or necessary, is set by pressing m. Moving onto a water tile can be done by carefully moving with Alt+direction key. This also works to move up out of water, as long as your character has some swimming skill.

Swimming

If an untrained swimmer jumps into water, four things happen; they start drowning, they are stunned from the impact, they are forced into a prone position (panicking or thrashing?), and their movement is reduced to a third of their speed.

To train swimming skill, find a pool of shallow water (preferably depth 1) to practice in. The speed of training seems to vary depending on the strength of the current; higher levels of water usually mean more current, and more pushing of your character around. Brooks count as ground tiles, you can't swim in them.