Why is the water source being ignored

dwarf-fortress

I need to empty a Murky Pool, and as I am fairly early in my fortress, I figured the easiest way to do this was to get my dwarves to haul all the water in buckets into an artificial pond.

I dug a sufficiently sized hole and added several Pond designations to it (so I could have several dwarves working on filling it). I also created a Water Source designation over the Murky Pool. Before long, several dwarves were hard at work emptying the pool. The water level in the pool dropped until it had less than 1/7 deep water per tile. About 30% of the tiles were dry, and the rest were at 1/7. At that point, the dwarves stopped getting water from the pool, and started emptying another nearby pool, which wasn't marked as a water source.

Since there are no other water sources on the map, why aren't they using the remaining water in the Murky Pool?

Best Answer

When the water level gets to 1/7, it's basically considered a "puddle", instead of actual water. At that point, the dwarfs can't scoop it up in a bucket, so it's useless. Since there are no other designated water sources on your map, your dwarfs default to just finding some water however they can, which in this case means other murky pools.

If your primary purpose was to empty out this particular murky pool, rather than to fill up your new pond zone, congratulations; you've done it. 1/7 water isn't real water, and it will evaporate entirely in a few minutes (probably).