40d:Aquifer

An aquifer is a subterranean layer of water-bearing rock. Attempts to mine through them will result in the mined-out squares immediately filling with water, effectively halting excavation at or below their level. This, in conjunction with the fact that they are often located in areas rich in clay, loam, and sand, makes it difficult to find great quantities of stone in areas with aquifers, making for more challenging gameplay.

Dealing with Aquifers

The challenges presented by an aquifer may be circumvented in several ways. Firstly, much more of your equipment will likely be made from wood, especially early on, so it may help to be in a heavily forested area. Once you've established your fortress a bit, you will also be able to trade for stone and metals if you run short.

It is also worth noting that it is by no means impossible to find stone on these maps, it is simply much rarer. It may help to create exploratory shafts searching for pockets of stone. Be aware that mining along the level immediately above the aquifer will result in patches of 'damp stone,' which will flood if mined out; these squares will flash with water when designating mining areas.

The Stone method

It is apparently possible on some maps to find patches of rock on the aquifers level these can be dug through to the level below with no ill effects. Perhaps your map includes several biomes and not all of them have aquifers. This method is the simplest method but relies on luck and some searching, and makes it hard to plan ahead since you dont know where the rock may be. Useful for newer players but more experienced players will probably find other methods easier.

If you have access to a supply of magma, you can create your own obsidian caissons. The water from the aquifer is not pressurized and magma is chunky, so it is safe to dig channels in aquifer. Though you will have to re-dig a lot of channels due to an element of chance, you can create a pool of magma on the aquifer z-level, and then pinch the pool off from the supply of magma with water. When it cools (which you can hasten with more water) you can dig down through the middle of a 3x3 patch of obsidian without flooding. With larger starting patches, you can dig through multiple levels of aquifer.

The Pump Method

It is possible to pump the water out of an aquifer; though the supply is apparently unlimited it can be pumped out faster than the water seeps in, allowing for a fairly safe area on the z level. This method is somewhat dangerous since problems with your pumps can lead to drowning, however, it allows a larger area to be cleared than the ice method and can be done anywhere. It's also easier to plan around a series of pumps than hoping you'll hit rock on the way down.

The Ice Method

There is a simple method of getting past an aquifer although it is restricted to a small shaft down, and not possible on all maps. You will need:

• 8 pieces of material suitable for crafting Walls
• 1 Carpenter or Mason (depending on your building material of choice)
• 1 Miner
• 2 grates
• A map which freezes during winter

steps:

1. Dig channels in a 5x5 square, but leave the middle square un-dug.
2. Build 2 grates so you can access the undug central square
3. Dig stairs down a level ensuring you build
4. Dig channels underneath all the other channels and build another down stair on the un-channeled pillar
5. Continue down in this way until you reach the water table
6. Wait for the water to freeze
7. Dig down the stair again the ice will prevent water from flooding the hole dig out the ice in a 3x3 area centered on the stairs, now build walls in the 8 squares bordering the stairs
8. You can now dig down another square to rock below the aquifier
9. This system can be expanded to allow for a bigger stairwell.

diagram:

• C - channel
• G - grate
• W - wall
• x - up/down stairs
• > - down stair
• I - Ice/water

First level:

CCGCC
CCGCC
CC>CC
CCCCC
CCCCC

Intermidiate levels:

CCCCC
CCCCC
CCxCC
CCCCC
CCCCC

Aquifer level:

IIIII
IWWWI
IWxWI
IWWWI
IIIII

Advantages of Aquifers

It's worth noting that the presence of an aquifer, while challenging, does offer some slight advantages. Firstly, much of the area underground but above the aquifer will be sand, clay, or loam, all of which can be planted in without requiring any kind of irrigation or flooding, allowing farming to get under way quicker and with less stress. Additionally, the presence of water 3-4 z-levels below ground anywhere on the map makes placing wells a simpler task, as well as ensuring easy access to subterranean water supplies.