40d:Well guide

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This guide assumes you've read the main article on wells and are familiar with the basic information found in that article, of what a well does and what is required to build one.

A well can be vital to any fortress, but deciding that you need one and building one are two different things. Draining water from the surface can flood your fortress if you aren't careful, and building a well only to see the water source dry up is beyond frustrating. This guide will walk you through several different situations, how to build a well by draining a pond, and by using a brook or river.

Choosing a Location

You want a well central to your dwarves, so they'll all get good thoughts from seeing it, and near any hospital beds you have. You can have more than one well, which solves that problem, but raises the one of engineering water to feed them all. If it's indoors (or behind walls), then there's no threat from carp, goblins, or animals, and it can provide a safe source of drinking water during a siege.

The important part about the well is to make sure that you don't create a situation where the water will flood your fortress, due to pressure from a source at a higher level. If the water is stable before you build the well above it, it will be safe (unless your dwarves change things), but if you are introducing a flow, make sure you understand how pressure works and will not fall victim to its surprises. (See pressure.)

Water sources

A well needs a water source of at least 3/7 depth, at least 1 z-level under it (not between it and the water, but on the next level immediately below the well). Pre-existing water is safe because it's the most predictable - what you see is what you got, no surprises. You can instead use dwarven engineering to bring water from a distant source to (beneath) your well, with a safety factor* based on your experience and the complexity of the project. (See flood.)

Pre-existing sources

A brook, river, or murky pool can provide water under a well. The surface of a brook tile will have to be channeled out, but it works just fine. Murky pools can dry up in warm seasons, and the well will be useless until they refill from rain. On hot maps, this may never happen - it's quite possible to see your murky pools (which are always full at embark) evaporate away before you ever get a chance to build a well - for this, see below.

Using stagnant water from murky pools or brooks is not optimal, as it will give dwarves negative thoughts, "Has complained about the nasty water lately". To avoid this, moving water from these places on to floor tiles that are not identified as riverbeds or ponds, and building a well over that will work just fine, so long as the final depth is 3/7 or greater.

Channeling water to your well

If the water is not where you want to build the well, you can dig a tunnel or channel and/or otherwise create an aqueduct to bring it to where you want it. You should consider adding a door or floodgate somewhere near the water source so that you can dry out your tunnels for future projects, repair, or recovery of lost items. Also consider a (secondary) drain, if feasible near a chasm or other large water-dump area. Bear in mind that the game lag produced by water constantly flowing from source to drainage can be as devastating to game play as any flood (depending on the capabilities of your computer).

Channels are very handy for moving water, but be cautious about leaving open water where it isn't necessary. A dry channel makes a great moat, but a wet channel is a random hazard, and dwarves have a nasty habit of diving into any available water for a variety of reasons. Instead of digging long wet channels, have a dwarf mine out extra one level down, bring him back out e.g. through a door, then channel the last square back up to the water source. Up+down stairs or a ramp on the level below can substitute for a channel for moving water, but be warned that any effort to "channel" out these to create empty space for a well means that the dwarf goes to the bottom level and gets rid of his means of escape upward. It is best to carve a ramp or two adjoining any open water without hostile inhabitants, such as muddy lakes, for dwarves to escape if they choose to. Leaving a stairs or ramp as an "emergency exit" is never a bad idea.

Long aqueducts

If you need to get water from a brook at the edge of the screen, it's never going to make it down that 1-square wide passage... and more surprisingly, it's not going to make it down a 5-square wide passage either, evaporating long before it arrives at the destination. The solution is that you need to put the aqueduct below the level of the river or brook, 1 square wide. Channel out a connected area of open space underground at the level of the brook bed, separated from the brook by one square of rock. Make sure you include a lever-controlled floodgate, get your miners out, and channel the edge of the brook. The amount of open space at the level of the brook bed controls how fast the water fills. Then dig wells down into the aqueduct normally.

For exceptionally long distances, you may have to install a floodgate every 100 tiles or so - filling the first section, then letting that spill out to the next, and so on, to avoid water so shallow that it simply cannot support the distance without evaporating at the same rate it is filling.

Aquifers

If you have an aquifer, just channel a 1x1 square in any open stretch of floor above it and build the well. You'll have other construction projects to worry about.

Safety

Any dwarves fighting (or sparring) near a well may accidentally dodge into it, usually resulting in injury, drowning and swift death. As such, you should keep military infrastructure, especially barracks, away from wells. Building escape stairs from your water source may also be a good idea, as well as teaching your dwarves to swim.

Style points

• Widen the area around the well, and make it a meeting hall. Smoothed or engraved walls and floors will make your dwarves happy. Smoothed and especially constructed floors will guard against tower-cap blockages, if that is a concern. The well has to be in a stone layer, not soil.

• Wells can be stacked on top of each other across multiple Z levels and still remain functional. A bucket dropping from a well on Z+2 will pass through a well on Z+1 to successfully reach water at Z+0.

• Add a gap between the channel and the stairs, then construct walls in the gaps. This avoids the aesthetic problem of muddy stairs inside your well. Be careful, your well will need to be twice as deep.

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#.OX#
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Special Considerations

Using ponds/pools

The highest priority for well building is if only "muddy pond" is available in a hot climate. These can dry out within a season or two after starting the game and will never return. Carve out a fairly large space to use as a reservoir and get that water down to an unexposed area. A reservoir can also be a handy precaution when tapping underground rivers with waterfalls or in other cases where you may not really be sure what the water level is.

Heavy rain means that it rains more in a year than a pool needs to be full, though pools or other existing water sources found on a map do not overflow. Being in a region with heavy rain has one big advantage - your pools will have more water than they need to be full. This allows them, over the course of a year, to provide more water than they can hold at any one time. Note that only naturally occurring tiles that are "murky pools" will collect rain - an identically size excavation next to a murky pool will not. Expanding a murky pool will allow the water to expand, but rain will only be "collected" in the original murky pool tiles, and any water that is 1/7 deep in the excavated tiles will tend to evaporate as normal for water. Aside from rain refilling murky pools, there is no way to actually collect rainwater in DF.

Using the well will take a very small amount of water from the water tile below (1/7 from that one tile), so it will eventually dry up if not replenished.

Salt water

Salt water is encountered near sea-forts, and reservoirs require that it is purified through a pump first, kept separate from any natural, non-constructed surfaces, and then held in a specially dwarf-constructed reservoir. However, a well will allow dwarves to drink from a salt water source without problem (although this may be a bug).

Step by step

Pond Draining Technique

1. Mine a one-square wide tunnel to a place near the pond to be drained.

~######
~#+++++
~######

2. Figure out how many squares of water are in the pond. You will need the same number of empty tiles below your well. Stairs do count as empty. The well does not need to be on the same level as the water.

3. Channel though the floor to the end of the tunnel. Your well will be on this tile, or directly below it.

4. Dig a staircase down, just behind the channel.

~########
~#.>+++++
~########

5. Repeat this stair and channel pattern as far down as you need. If in doubt, make it a level deeper than you need.

######
##.X#
######

6. If you run out of depth, just make the bottom wider.

#####
#+++#
#+.X#
#+++#
#####

7. Almost ready to drain the lake! Check for any leaks. You might want to place a door behind the channel, as a precaution.

8. From the surface, channel through the last square separating the pond from the tunnel. Wait for all the water to drain into the well.

9. Build the well. You can make it anywhere above the water surface. You might want to widen the tunnel so more dwarves can access the well at once.

######
#+++##
Do++D+
#+++##
######

10. Install a door to seal off the dry lake. (Or use a wall, but this might cause a dwarf to trap himself in the lake bed.)

Aquifer Technique

A small 1x1 Stair down to the aquifer is mostly the only reason to have an aquifer at all.

Style points

• Widen the area around the well, and make it a meeting hall. Smoothed or engraved walls and floors will make your dwarves happy. The well has to be in a stone layer, not soil.

• Add a gap between the channel and the stairs, then construct walls in the gaps. This avoids the aesthetic problem of muddy stairs inside your well. Be careful, your well will need to be twice as deep.

#####
#.OX#
#####

Using ponds/pools in areas with heavy rain

Heavy rain means that it rains more in a year than a pool needs to be full, though pools or other existing water sources found on a map do not overflow. Being in a region with heavy rain has one big advantage - your pools will have more water than they need to be full. This allows them, over the course of a year, to provide more water than they can hold at any one time. Note that only naturally occurring tiles that are "murky pools" will collect rain - an identically size excavation next to a murky pool will not. Expanding a murky pool will allow the water to expand, but rain will only be "collected" in the original murky pool tiles, and any water that is 1/7 deep in the excavated tiles will tend to evaporate as normal for water. Aside from rain refilling murky pools, there is no way to actually collect rainwater in DF.

Tapping a Brook

A brook can be tapped to supply constant water for a well, if you have one in your area.

WARNING: Trying this downstream from a waterfall doesn't seem to work; the water pressure it produces is too high, you will flood your fortress (unless you use floodgates to control it).

You'll need to understand the basics of digging, etc., as much is glossed over in this particular guide.

1. Dig out a room similar to the one below. It's easier if it's one z-level above the brook itself but that can be addressed several ways. The room itself could be different, perhaps even just one square of a channel, where the well will be placed. Whatever you prefer.

z-0:

	  ###+###
	  #+++++#
	  #+++++#
	  #+++++#
	  #.....#
	  #######

OR

	   #+#
	   #.#
 	   ###

2. Connect your channel from the room above to the brook as follows. The tunnels can be wider, longer, and can drop a z-level or two if you need to by various methods. You'll need some way for the miners to get down here; access from other rooms on that z-level by door, staircase, whatever.

z-1:

        ###########
        #+++++++++#
        #+#######+#
        #+#     #+#
        #+#     #+#
        #+#     #+#
        #+#     #+#
        #+#     #+#
############################
@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@@@@@@@@@@@@@@@@@@@@@@@@@@@@
############################

3. Mine the last two wall segments, your miners should easily outrun the water to the safety of a staircase/door. From then on you should have a perpetual water source. It will fill the trench tiles to 7/7 but should not overflow into your fortress proper, as the water is returned to the brook and thus the pressure does not build up.

4. Build a well on one of the channel squares in your original room and cover the others with floor grates/floor hatches. Or, if you chose the smaller room, build the well, you're done.

Water FAQ
How do I move water up levels?
How do I stop water moving up levels?
Can dwarves swim to the surface for air?
How long does it take for a dwarf/goblin/creature to drown?
How deep is the water?
Is it possible to melt ice?
How do I build a well?
How do I channel a path for water?
Will water push items around?
Can I build a dam to stop the water?
Digging designation canceled: Damp stone located
What is the best way to proceed on a map with no rivers? Will my dwarves die of thirst?
How can I divert a river to allow safe(ish) indoor fishing?
How can I dig through an aquifer?
How do I purify my water?
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