Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[soulsource]

I'm wondering about the z-variation of aquifers.
Assume one breaches through an aquifer at a high-elevation point (a hilltop or something like this), and starts digging horizontally two z-levels below the aquifer. Two levels, as aquifer blocks will spawn water directly below them. At some point the aquifer has to follow the shape of the hill, so that by just digging horizontally, one will end up just one z-level below the aquifer, meaning that the tunnel would get flooded.
Does Dwarf Fortress warn of damp blocks in such a case?

Or, phrased differently: Are the blocks directly below an aquifer reported to be damp if one digs into them from the side?

Sketch (side view - S=soil, X=stairs, R=rock, A=aquifer, W=wall)

        SSSSSXXSSSSSSS
    SSSSSSSSWXXWSSSSSSSSSSSS
SSSSSSSSAAAAWXXWAAAAAASSSSSSSSSSS
SSSSAAAAAAAAWXXWAAAAAAAAAAAASSSSSSSSSS
AAAAAAAARRRRRXXRRRRRRRAAAAAAAAAAASSSSSSSSSS
AAAARRR?     XXRRRRRRRRRRRRRAAAAAAAAAASSSSS
RRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRRAAAAAAAAAA

What happens when digging at the question mark? Will there be a warning, or will there be *fun*?

[Iamblichos]

You get a warning about damp stone digging in any direction except up.

Digging down, yes, damp stone.  Same from the side.  If you were at the question mark and punched a stairway upwards, though, you would get no warning... but you would get a nice bath 

[soulsource]

Thanks a lot! Now that I know that horizontal digging should be safe unless one ignores damp stone warnings, I can start to extend my freshly founded fort without worrying too much about drowning my dwarfs.
I just wasn't sure if the stones directly below the aquifer are being treated as damp, as they are not shown as damp when piercing through the lowest aquifer level by building stairs from above (until the aquifer spawns water on the stair tile). Probably the damp flag gets removed as soon as one removes the aquifer tile, as there is no source of water adjacent any more, and gets set back when there's actual water above it.

[escondida]

Even though you get the warning, I'd say it's still probably best to have your fort's first stone layer at least 2z under the aquifer, Just In Case™.

[ImagoDeo]

Even though you get the warning, I'd say it's still probably best to have your fort's first stone layer at least 2z under the aquifer, Just In Case™.

Then tap the aquifer to fill all your cisterns and to power your water wheels and to drown your goblins.

[soulsource]

Then tap the aquifer to fill all your cisterns and to power your water wheels and to drown your goblins.

That's exactly what I'm planning, but I'll try to do all of this on the top of the aquifer, in order to be relatively safe from drowning my fort.. Also, as annoying as aquifers tend to be, on my current embark I'm very happy to have one, as the surface is an unexpectedly nasty place. I was prepared to face wild beasts and the cold weather, but there are things coming over from the neighboring forest that should not be able to move any more... That's why building aquifer powered water wheels is definitely preferable to sending out dwarfs to get their heads bitten off by undead ravens while trying to mount a windmill.

Meanwhile, thanks to your answers, I've started digging around below the aquifer, and I can confirm now from my own experience that there's a warning while mining horizontally.

[escondida]

You don't have to dig your fort into the filthy dirt layers like some human cellar. As long as you have at least one layer of some between you and the aquifer, you're golden. If you design your fort to take advantage of multiple z-levels, too, you don't have to worry about unexpected outcrops of aquifer further down than the rest.

Tapping an aquifer from below can be done safely by simply having a pressure limiter (see the wiki on pressure) at any spot you want the water to stop falling and start moving on that z (for instance, at the top of your cistern).

[soulsource]

My fort is mostly located below the aquifer. There are currently only six things above it:

• The trade depot. I didn't want to bother making the aquifer breach big enough to allow wagons to pass.
• Barracks. I like to have them close to the entrance, just in case something nasty tries to sneak in.
• Underground farm plots and pastures - there wasn't enough time to irrigate below the aquifer yet, and I'm not sure if that'll be necessary at all.
• A water source. It had to be built quickly, so it's just a hole into the aquifer for now.
• Water wheels. I didn't feel comfortable draining the aquifer into the caverns, and the easiest way to get flow is to drain aquifer level z into aquifer level z-1
• The refuse stockpile. It was just convenient to re-purpose the now covered hole used to freeze through the aquifer, as it is inside, but above ground, so it should be miasma-safe.

Currently I'm working on breaching the aquifer a second time in order to transfer the power of the water wheels to a more suitable location. It'll take some time though, as I'm planning to use a pump-based method instead of freezing the aquifer - undead ravens spawn on the surface every once in a while, and I won't be so stupid as to leave a big hole into my fortress open again. The last time, which was started before I knew that undead animals would show up, I already lost two dwarfs...

I'm also considering building a pressure limited water source below the aquifer, right next to the hospital. I'm only worried about the miner who will have to dig into the aquifer. Do you think a door is enough to let the miner escape, but keep the water under control? Or is this too risky? (I'd seal it off properly afterwards...)

[Sanctume]

My fort is mostly located below the aquifer. There are currently only six things above it:

• The trade depot. I didn't want to bother making the aquifer breach big enough to allow wagons to pass.
• Barracks. I like to have them close to the entrance, just in case something nasty tries to sneak in.
• Underground farm plots and pastures - there wasn't enough time to irrigate below the aquifer yet, and I'm not sure if that'll be necessary at all.
• A water source. It had to be built quickly, so it's just a hole into the aquifer for now.
• Water wheels. I didn't feel comfortable draining the aquifer into the caverns, and the easiest way to get flow is to drain aquifer level z into aquifer level z-1
• The refuse stockpile. It was just convenient to re-purpose the now covered hole used to freeze through the aquifer, as it is inside, but above ground, so it should be miasma-safe.

Currently I'm working on breaching the aquifer a second time in order to transfer the power of the water wheels to a more suitable location. It'll take some time though, as I'm planning to use a pump-based method instead of freezing the aquifer - undead ravens spawn on the surface every once in a while, and I won't be so stupid as to leave a big hole into my fortress open again. The last time, which was started before I knew that undead animals would show up, I already lost two dwarfs...

I'm also considering building a pressure limited water source below the aquifer, right next to the hospital. I'm only worried about the miner who will have to dig into the aquifer. Do you think a door is enough to let the miner escape, but keep the water under control? Or is this too risky? (I'd seal it off properly afterwards...)

It's easier to breach aquifer from the bottom.  Dig a drain to the map edge ending a carved fortification. 
Then dig stairs up, smoothing walls or construcing wall along the aquifer levels.
Water will drain down below and will toggle between 1/7 and 2/7 so the building of walls suspend is minimal.

[ldog]

My fort is mostly located below the aquifer. There are currently only six things above it:

• The trade depot. I didn't want to bother making the aquifer breach big enough to allow wagons to pass.
• Barracks. I like to have them close to the entrance, just in case something nasty tries to sneak in.
• Underground farm plots and pastures - there wasn't enough time to irrigate below the aquifer yet, and I'm not sure if that'll be necessary at all.
• A water source. It had to be built quickly, so it's just a hole into the aquifer for now.
• Water wheels. I didn't feel comfortable draining the aquifer into the caverns, and the easiest way to get flow is to drain aquifer level z into aquifer level z-1
• The refuse stockpile. It was just convenient to re-purpose the now covered hole used to freeze through the aquifer, as it is inside, but above ground, so it should be miasma-safe.

Currently I'm working on breaching the aquifer a second time in order to transfer the power of the water wheels to a more suitable location. It'll take some time though, as I'm planning to use a pump-based method instead of freezing the aquifer - undead ravens spawn on the surface every once in a while, and I won't be so stupid as to leave a big hole into my fortress open again. The last time, which was started before I knew that undead animals would show up, I already lost two dwarfs...

I'm also considering building a pressure limited water source below the aquifer, right next to the hospital. I'm only worried about the miner who will have to dig into the aquifer. Do you think a door is enough to let the miner escape, but keep the water under control? Or is this too risky? (I'd seal it off properly afterwards...)

It's easier to breach aquifer from the bottom.  Dig a drain to the map edge ending a carved fortification. 
Then dig stairs up, smoothing walls or construcing wall along the aquifer levels.
Water will drain down below and will toggle between 1/7 and 2/7 so the building of walls suspend is minimal.

That's assuming you can get under it in the 1st place. I always look hard for an embark that has a partial aquifer (because they are downright useful), but if you've got 1 covering the entire embark there's no choice but to go down.

[Sanctume]

My fort is mostly located below the aquifer. There are currently only six things above it:

• The trade depot. I didn't want to bother making the aquifer breach big enough to allow wagons to pass.
• Barracks. I like to have them close to the entrance, just in case something nasty tries to sneak in.
• Underground farm plots and pastures - there wasn't enough time to irrigate below the aquifer yet, and I'm not sure if that'll be necessary at all.
• A water source. It had to be built quickly, so it's just a hole into the aquifer for now.
• Water wheels. I didn't feel comfortable draining the aquifer into the caverns, and the easiest way to get flow is to drain aquifer level z into aquifer level z-1
• The refuse stockpile. It was just convenient to re-purpose the now covered hole used to freeze through the aquifer, as it is inside, but above ground, so it should be miasma-safe.

Currently I'm working on breaching the aquifer a second time in order to transfer the power of the water wheels to a more suitable location. It'll take some time though, as I'm planning to use a pump-based method instead of freezing the aquifer - undead ravens spawn on the surface every once in a while, and I won't be so stupid as to leave a big hole into my fortress open again. The last time, which was started before I knew that undead animals would show up, I already lost two dwarfs...

I'm also considering building a pressure limited water source below the aquifer, right next to the hospital. I'm only worried about the miner who will have to dig into the aquifer. Do you think a door is enough to let the miner escape, but keep the water under control? Or is this too risky? (I'd seal it off properly afterwards...)

It's easier to breach aquifer from the bottom.  Dig a drain to the map edge ending a carved fortification. 
Then dig stairs up, smoothing walls or constructing wall along the aquifer levels.
Water will drain down below and will toggle between 1/7 and 2/7 so the building of walls suspend is minimal.

That's assuming you can get under it in the 1st place. I always look hard for an embark that has a partial aquifer (because they are downright useful), but if you've got 1 covering the entire embark there's no choice but to go down.

soulsource mentions he already did pierce the aquifer once, and planning to breach it a second time using pump-based method