Dwarf Fortress’ aquifers are underground layers of soil or stone that produce water. The first place you’ll run into them is while trying to select an embark location. Finding the perfect embark location in Dwarf Fortress can set you up for success or (immediate) failure.
In our other guides, we told you to avoid aquifers, since flooding your fortress usually just leads to fun outcomes. Avoiding aquifers altogether, though, dramatically limits the available places for your fortresses.
The good news is that aquifers aren’t too hard to deal with, as long as you know what to do. With a little knowledge and planning, building in an aquifer even has benefits — like a secure and indoor source of fresh water.
In this Dwarf Fortress aquifer guide, we’ll explain what aquifers are and then tell you how to deal with them.
While your dwarves are digging into the earth, they might encounter damp soil or stone. You’ll get an alert in the upper left, and any digging jobs that cross that damp stone will be cancelled — meaning you’ll have to re-designate those blocks for mining. With default settings, your game will also automatically pause so you can figure out how to deal with the problem.
A damp stone alert just means that there’s water saturating the block your dwarves have just exposed — either there’s water above it (like a pond or a river) or it’s an aquifer. Check the block above it to figure out which it is.
You’ll be able to see where the damp stone is located any time you open the Mining menu (m). A saturated block will have a water droplet icon over it, but only when you’re mining.
Aquifers in Dwarf Fortress
When you expose an aquifer block, it will start producing water on any open block nearby. Aquifers generate water orthogonally — to the north, south, east, or west only — from the source block.
Light versus heavy aquifers
The difference between light and heavy aquifers comes down to how fast they produce water. Light aquifers generate water on a timeframe across in-game weeks and months, whereas heavy aquifers generate water every in-game minute (basically instantly).
Beyond generating water, aquifers also absorb water. Functionally, what that means is that an aquifer layer will never flood the layer above it — it will never generate more than a 7/7 water depth. (You can check a numerical measure of water depth by hitting f.)
This holds true even if you dump water in from above. This means that an aquifer will only ever generate water one block deep, even if you dig through multiple levels of aquifer.
Once you expose an aquifer, you have a few options for preventing the inevitable flooding. Two of them are simple and permanent (building Walls and Smoothing stone) and the other one (building Screw Pumps) takes a bit more work and is only temporary. Basically, building a pump allows you to drain enough water to do one of the other solutions.
Only naturally generated blocks in an aquifer create water, so a constructed block — like a wall — is safe. Dig an extra block around whatever you’re mining through an aquifer and replace the edges with walls.
Construction can only take place on blocks with less than 2/7 water, so you’ll have to be quick about it. (Remember, you can see how deep the water is numerically by hitting the f key.) If the water gets too deep, you’ll need to build a Screw Pump (below).
If the aquifer is in a stone layer — not a sand, clay, loam, or silt layer — you can instead choose to Smooth the walls (and the floor if you want) with v. Select Smoothing with m and highlight the walls. Smoothing stone walls prevents them from generating water.
Heads up that smoothing does not work on soil. On those levels, you’ll have to stick to building walls.
A Water Pump moves water from a source block, up one level, and then two blocks forward (you decide which direction when you build the pump).
Placing a Screw Pump is a little tricky. The source block has to be below the pump, so you need to channel out a block to gain access to water on the level below.
At the front end of the pump, make sure there are walls — either natural or constructed — blocking the water from flowing back.
Once you have your location set up, go to Build (b) > Machines/Fluids (m) > Screw Pump (p) to build one. Screw Pumps require a few things: one block (either a wooden block from a Carpenter Workshop or a rock block from a Stonemason’s Workshop), one enormous corkscrew (either a wooden one from a Carpenter’s workshop or a metal one from a Metalsmith), and a pipe section (either a wooden one from a Carpenter’s workshop or a metal one from a Metalsmith).
Once a pump is built, you can turn it on by clicking on it and checking the box next to Start Pump Manually. (It’s also possible to power a pump with a Windmill or Waterwheel, but that’s a lot more work.)
Pumps will never lower the source block below 1/7 water depth, though, so the best use is to drain the aquifer block(s) long enough to build a wall or smooth the stone (above).
If you’re ready (and willing) to deal with them, aquifers can be a secure, convenient, and relatively safe source of drinking water for your fortress. Just dig out a room in an aquifer level and wait for it to fill with water. Either mark that as your water source or, if you’re feeling fancy, build a well above it.