Mist is created by water falling from one Z-level to another, from ocean waves, and from items or creatures skipping across water. The mist is generated on levels below the top level (from which the water drops), but spreads out similar to miasma and therefore can appear even on the top level. Walking through mist generates a happy thought for a dwarf.
not confuse mist with magma mist.
 Generating Mist
Simply put, screw pumps are daisy chained (output to input) in a circle and then water is added to the system. Water is typically added by designating one of the inputs to the pump a Pond and having dwarves fill it up. Once water is dropped from the floor above it is immediately sucked up by the next pump. Since there is falling water, mist is generated. Ahh, lovely waterfalls!
Below is an example of a simple mist generator. The Z=0 level can be anything, a booze stockpile, barracks or even your atom smasher.
Pump Floor (z=1) ▒▒▒▒▒▒ ▒.÷÷.▒ ▒÷ ÷▒ The water can go clockwise or counter clockwise. ▒÷ ÷▒ Make sure your pumps are correctly aligned. ▒.÷÷.▒ ▒▒▒▒▒▒Some important considerations:
- Evaporation is nonexistent as long as the pumps are working and the water is moving even above ground.Verify
- Job cancellation spam is possible if the water is filled to greater than 4/7 and a dwarf walks where the water falls. Even then, this can be prevented by blocking access to these tiles without blocking the water, such as by placing a statue underneath or greatly reduced by setting them as restricted traffic areas.
- Mud will form where ever the water falls. Subterranean trees can sprout up and clog the system. Solutions to this problem include: statues, paved roads, constructed floors or fortifications, or to simply channel out the space once the mist generator is running.
- The z=-1 layer can also be identical to the z=0 level. Mist will also be generated there. Because the water never touches the floor there, you don't have to worry about muddy tiles.
- This system is generally only capable of maintaining a single 7/7 square of water, due to the way water descends z-levels. Any additional water put into the system will quickly overflow into the pump chamber (z=1).
- Automated mist generators may significantly lower your FPS, particularly if multiple generators are used.Verify This might be remedied by triggering via a repeater with a long delay or by one or more pressure plates (perhaps set to activate by a passing dwarf).Verify
A movie  best illustrates the operation.