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[Merijeek]

So...I seem to have some really bad luck with water. Maybe I should stick to the tropics.

Anyway, the problem I have is that winter comes and my water freezes. So, I figure I'll make a cistern. I dig out a 10x10 cistern that's a couple levels deep and channel some water into it.

And it freezes anyway.

So I reload and make an underground cistern that is about 10 Z-levels down from my main fortress, put a well over it, tunnel to a shaft, and then pump water with a screw pump from a stream to the shaft. Sure, it's kind of annoying that water overflows the hole for my shaft (is there any way to fix that?), but the really annoying thing is that the well in my dining room (or worse, my hospital) starts to flood the room. It sucks even harder when I've got a room that's flooding but the well is STILL DRY because the first Z-level that has water is only at 2/7.

So, how do I correctly make a cistern? I've looked at the wiki, and man that is a bad explanation and a terrible diagram.

Thanks
-Joe

[gtmattz]

You have to make sure the cistern is 100% subterranean.  That is, dont just channel out a hole in the ground and expect it not to freeze, you need to make the top level of the cistern on z-1 with no access to the outside.

[white_darkness]

If an area shows as being "above ground" whether "light" or "dark" it will freeze.  Used to annoy the devil out of me when the hatches on my drowning chambers would pop off in winter.

So your first problem is that you're pumping water from a stream to a vertical shaft?  One thought would be to just eliminate the pump and then have a horizontal tunnel running to the shaft under the surface (so it's not exposed) and then you can build something lever operated over at the stream side to completely seal things off (if needed).

Once you get down to the cistern, I'm assuming  that the wells are off feeder tunnels excavated at the bottom of the cistern?  So you've got a 10 z-level tall cistern with feeder tunnels for the wells on the bottom and the actual wells on the level above?  If the tunnels are straight, the cistern will never fill.  Water pressure is transferred in the horizontal, and vertical but not diagonal.

The only way to fill if you have straight tunnels is to flood your fort.

You could alter the feeder tunnels to have a diagonal bend or two at some point and this would eliminate the water pressure and then you could fill up the cistern.

top down view:

Code: [Select]

OOOO
OOXO
XXOX
OOOO
With O being solid walls and the X being the tunnel.  That's seriously all it takes.

The diagonal twist definitely works, my only well is connected via a 10z level drop to my entrance/drowning chamber/mist generator which continuously pumps water in a 2-z level circle.  Though by logic all the water should just flow down the feeder tunnel to the well cistern and come pouring out of the well.  It doesn't since it has to travel diagonally on the horizontal.

[Merijeek]

"If the tunnels are straight, the cistern will never fill.  Water pressure is transferred in the horizontal, and vertical but not diagonal."

Is, I think, what is confusing the hell out of me.

Maybe I need to know the definition of "pressure". Are you saying that water will flow down that kinked hall, but that the water pressure gets set to 0?

-Joe

[Jelle]

Yes, the water will not rise above the waterlevel where it passes a diagonal path.

[Torgan]

Could also try tunneling down until you find a cavern with a lake in it, either place a well directly over it or syphon off some of the water into a cistern you've dug.  It's probably better to go for the latter as a well acts as an open space so a flying beastie could fly through the hole and get into your fortress from the cavern,

If you dig out a cistern build a fortification between the cavern lake and your cistern (with a floodgate on the cistern side), this should stop anything except water getting into your cistern.  There can be a bug where the water pressure pushes a beast through the fortifications but it's either been fixed or it's very rare.

[fox967]

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This is what i do.

First, i plan out my 'main fortress', so i know where everything is going.
Second, i dig upwards, from the cistern, to the river. Water travels down stairs, so its no problem. I also dig the hole for the well.
Third, i place doors and floodgates, and link em up, so that i can stop the water into the cistern.
And fourth, after its all set up, i channel the side of the river (the bright green bit on my very artistic picture), and let the water flow. This way, i have a nice supply of water.

[greycat]

If I don't have an aquifer, then what I do is dig an underground cistern, which is really just a room.  I generally have two tunnels leading into it -- one for the miners to get in and out of, which is blocked off by a floodgate once they're done in there.  The other is the water input source, which I do not block off (any more -- I did when I was still learning, and having a lever-triggerable floodgate there sure doesn't hurt).

The vital, important, imperative thing is that the water input tunnel leading into the cistern must NOT be able to push the water up through the well that's over the cistern.

So, the way you do that is make sure the water goes through a diagonal AFTER the Z-level drop.

Code: [Select]

############
#.......##<#  water falls down a staircase here, from tunnel to brook or river
#.......##.#
X.........##  water goes through a diagonal here, so it loses pressure
#.......###
#.......#     
#########

In chronological order:

• Dig the cistern, including the tunnel up to the river or brook, but do not dig out the last tile that would cause water to start flowing.
• Remove rocks, ore, gems, whatever you want to salvage.
• Install floodgate on the brook-facing side if you want, and link to a lever.  This is a safety measure, and not 100% required, but... you know how it goes.
• Designate a constructed wall just inside where the non-brook-facing-side floodgate will be, and suspend construction of it immediately, so that dwarves will not stand INSIDE the cistern when installing the last floodgate.
• Install the last floodgate.  Un-designate the constructed wall that never got built (q x).
• Channel out the last tile of the tunnel leading to the brook or river to let water flow in.

That's it.  The water is underground, so it won't freeze.  If the brook/river freezes, no new water will flow in during that time, but if the cistern is large enough to last throughout the winter period (which really doesn't have to be very big at all), then you should be fine until it melts and refills the cistern automatically.

It's entirely gravity-fed.  There's no pumping, no labor of any kind, no wind/hydro power requirement.  If it's set up correctly, there's also no danger....

[Waterbreath]

Hiho!

I have built something like it was suggested here, with nice floodgates and a room, that stores water for my fortress deep underground. This already works to flood rooms for irrigation (two rooms ready for planting booze-mushrooms)


Now my problem: I thought I could build a well in the room above my water-storage-room and just start pulling up water for my dorfs. But when I try to build a well, it says "Needs open space" - what am I doing wrong? How do I get my dorfs safely to the water?

Best regards,
WB

[Torgan]

You need to channel a hole in the floor, you build the well over the hole so the bucket can go down into the water and draw it back up.

[Waterbreath]

This... makes perfect sense. Thanks!

[Torgan]

This... makes perfect sense.

It happens occasionally in Dwarf Fortress.

[Waterbreath]

Yes it works

Although the water-pressure was toooo high at my first try... thought that damn dorf could pull the lever close, but he got washed away...

the next try had a second water-stopping layer to it and now it works perfectly. Although I plan on another well-with-reservoir deeper down and maybe use the no-pressure trick.. although now I can flood the fortress in case I get overrun...