So you have found the perfect embark but it has one of those pesky aquifers? Fret not, breaking through is way easier than you think and then the aquifer is actually quite useful.
The premise for the below methods is always, that we want to get a single stair through the aquifer as quick as possible. Then it's easy to dig larger openings (or even mine out the entire aquifer layer) from below. These methods are probably not new, but I have not seen them mentioned anywhere so here goes.
Getting through aquifers, located exclusively in the soil layers is easy (just look at the first few steps of the below methods) so we will deal with deep aquifers extending into the stone layers.
If done correctly, all three methods should be 100% safe for the miner -- doing everything correctly on the first attempt is probably hard though.
Some general remarks:
Usually it's possible to tell what you are dealing with, before even starting to dig. The embark screen tells you if there is an aquifer present and how many soil layers there are. If there is an aquifer, the first two soil layers are dry and then any layer, that can bear an aquifer, will do so. From looking at the pebbles and rocks on the surface you can then decide, wether your aquifer extends into the stone layers (only sandstone, conglomerate, puddingstone) or not. In the former case you will have between three and seven layers of wet stone. I've read about different layouts, but never encountered one.
In the proceedings below we assume that there are two wet soil layers. If there is only one, there are some short cuts. With more than two wet soil layers the methods don't work anymore but I've never seen that (on a flat embark anyway). If someone has an example embark, I'd be interested to experiment with it.
All the methods below depend on digging around in an aquifer layer. To accomplish this, a stair is dug in the level we are working in, and then another stair as a drain in the level below. Designating can be a hassle due to all the wet stone warnings, but I find it manageable with macros. Do not dig more tiles than nescessary without opening drains underneath.
Cave-ins will be used in various places. These can be set of safely, even without access to mechanisms or building materials, by removing the last connecting tile from a diagonal. Just like miasma, cave-in dust does not spread diagonally. There is also a bug, transforming soil material in a cave in into the layer material it is dropped in. It's fine since the dropped tiles will not be aquifer tiles anyway.
If you have access to building materials, various short-cuts are available but the aim is to get by with as little as possible.
This method ist the most versatile and the quickest way to break through an aquifer that I know of. You will need a pump, a pick and two beards and since a pump can be produced from the embark wagon wood, this should be possible in almost all cases.
Though getting through the soil layers using only the pump is possible, it's much easier to do by cave-in.
While the components for a pump are being produced, you can prepare the ground above the aquifer. When ready, the pump is assembled (here pumping from the west).
Once the pump is activated, the up-down-stair can be extended two levels down. Then the pump can be disassembled. Meanwhile you prepare the landing site for a plug on Z2. It is important, that the outer ring on Z2 are up-stairs since we will dig under them. It is equally important, that the other tiles are down-stairs since up-stairs are, unlike ramps, not crushed under a cave-in.
If you use a different layout, make sure that the pump components are safely out of the cave-in area. Then the plug is dug out, removing the last tile safely from a diagonal.
The plug is just large enough to place the pump inside and prepare an access to Z3. Don't replace the up-stair with an up-down-stair, since you will need a floor there later.
The down-stair on Z3 can be dug from the level above, even though the tile is flooded and it allows us to know wether there is another aquifer layer beneath. After the pump is activated, you can start smoothing the accessible tiles on Z3 and dig a new drain on Z4.
When the drain is done, the pump can be disassambled again and the up-down-stair can be connected to a down-stair on Z2.
Now prepare the space for the next pump. The channeling will take a while since the miner is being pushed around a fair bit but it will get done eventually. It might help to have an agile (and strong?) miner here.
Once this is done, remove the up-stair, construct the pump again and channel its intake tile.
And that's it essentially. You can continue like that, alternating between NS and EW direction for the pump, until reaching the last aquifer layer. Don't dig any stairs further down before all the tiles have been smoothed.
How long the process takes varies quite a bit, probably due to all the being pushed around by water.
On my test embark, I broke through on the 20th of Slate before the miner got hungry for the first time.
Further remarks:
- If you have only one wet soil layer, you can skip the cave-in. Just make an "island" in the first aquifer layer by digging a ring of stairs with drains below, shaped like the outer ring on Z1 (of course your lower layer would be stone).
Dig the stairs and drains first, then dig out the aquifer tiles inside the ring. - If you are on a glacier (or frozen ocean, I guess), where the first dry layer is ice, you cannot place the pump in this layer, since the pumped-out water will freeze immediately rendering the pump inoperational. Freeze your way into the first layer as seen in the picture (again, you'd have a stone layer).
Then dig stairs into the single remaining soil tiles and continue as before. Alternatively, you can use method II. - With a slightly larger plug at the beginning, the method can easily be extended to result in a 3x3 (or possibly even larger) stair centered at the pumps intake tile.
For this method, you don't need anything but a miner with a pick and freezing weather.
Channel five tiles on the surface as shown in the image. All except the channel in the north-western corner can be extended right into the first aquifer layer. The channels can be floored over immediately.
Dig a stair in the center of the frozen tiles, then channel the ice on Z1 and then again on Z0.
This will create ice walls on Z1 and Z2. Dig a stair through the center again extending it into Z3 to make a drain.
Now on Z2 dig a ring of stairs with drains underneath.
When the ring is complete, extend the stairs to Z1 and channel the remaining aquifer tiles inside of the ring from Z1.
Now you can channel the ice walls as well as the tile to the north-west of the central stair all the way down to Z2. Z3 should then look like this.
There is still water trapped in the center. Just keep channeling the same ice tiles on Z2 until it spreads sufficiently to allow the miner to stand on the stair. Then extend the central stair to Z4. When this is done, dig out the NE and SW corner tiles and smoothe some tiles.
With Z3 dry, channel out the ice tiles again and repeat the process until you hit dry stone (then don't dig into the corners obviously).
On my test embark I broke through on the 3rd of Felsite, but the miner fell asleep immediately before finishing so it can likely be done quicker.
Further remarks:
- This is the quickest method on a glacier, where the aquifer is exclusively in the stone layers. In this case you can skip the first part.
- If you only dig one corner at a time, the dwarves smoothing the stone will be pushed around less.
- You can also freeze your way to Z1 and then, instead of digging the ring of drains, drop a plug around the ice tiles into Z2, which is probably faster. Don't do it with ice walls though since these will eventually melt (or so I believe).
- You can probably speed up the process, by freezing two levels at a time, as was done for the two soil layers, and digging up-down-stairs in the corners on both levels at once.
- You can also repeat the entire process done for the soil layers a second time in the aquifer layers 3 and 4. You only have to use down-stairs instead of up-down-stairs to make the ring. Once the ring is complete, the up-stairs on Z2 can be transformed into up-down-stairs from above. To continue beyond 4 aquifer layers in this fashion, the method needs to be adjusted or you need a means of walling off the higher aquifer layers. Otherwise there will be too much water.
This method needs nothing except a pick and a dwarf to wield it. Since you can use the wagon wood to construct a pump, it should rarely, if ever, be necessary to resort to it. Situations in which you might include:
- you needed some wood to ensure survival early on
- you needed some wood to make the pick
- your embark wagon is the center of a zombie apocalypse
- you are (by choice or otherwise) playing a hermit challenge
- any combination of the above
As a first step, you need to get into the first aquifer layer using a cave-in (of course you could also use a pump, but if you have a pump, why are you doing this in the first place.). In a fashion similar to the beginning of method I, prepare the landing site for a larger plug.
Notice the single unbroken tile on Z2. To the west,you can see the initial plug, except you can't see it due to the soil-transforms-during-cave-in bug. Now prepare the plug, cutting out a smaller, inner plug for later use. The inner plug is suspended by a single remaining tile.
Once the dust settles, dig through the freshly dropped plug, establish a drain underneath and dig a diagonal, cutting away the last aquifer tile inside of the ring and letting the trapped water drain away.
Once that is done, the landing site for the inner plug on Z3 is prepared
and the plug cut loose. The plug is held by a thin strech of floor on the surface. You have to watch your miner closely here, or the dunderhead will carve the ramp from the surface, promptly to be sweapt into the hole by the cave-in dust.
The collapsed floor covered one of the stairs on Z1 so make sure to open that up again before going on. When the water has drained away again, you can dig through the center of the latest plug and again make a drain below. Yet again dig out through a diagonal. Before going on, all reachable tiles are smoothed.
Go on digging on Z3 making drains on Z4 as needed. Take care not to open up several tiles at once and smoothe each tile as soon as it gets exposed. It's also important to separate the various drains as seen in the picture lest the miner get flooded when working on the lower levels.
The northernmost stair extends all the way through the aquifer and will be the access to the pit after the next cave-in. Now channel around the second inner plug and remove the up-stair below.
The second inner plug is now held by the single up-stair and can be dropped by removing it -- again from a diagonal.
Work on Z4 proceeds essentially as on Z3 rotated by 180°.
The northern up-down-stair on Z4 is flooded so before you can dig the drain underneath, some more work needs to be done on Z3.
Finally, dig the missing drain on Z4, channel around the plug again and set of the next cave-in.
From here on, essentially repeat the previous steps.
Of course the process is rather lengthy, but it's not that bad. On my test run, I got through on the 23rd of Hematite. I didn't try particularly hard to optimize anything so i'm sure it can be done in less than a season.
Further Remarks:
- Getting the miner to stand in the correct place while setting off the cave-ins can be a hassle. In my test run, I had the meeting area to the north of my dig site, which took care of that problem.
- If the surface is too dangerous, you can get into the first aquifer layer using "chicken runs", which does come with a slight risk of drowning your miner. You will have to support, and eventually cut loose, the initial interiour plug from below. Again there is some risk, but in my experiments channeling a supporting stair from inside the ring worked surprisingly well.
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Topic: Fun with Aquifers (Read 1950 times)