Bay 12 Games Forum

Dwarf Fortress => DF Gameplay Questions => Topic started by: Tachytaenius on November 27, 2022, 06:58:54 pm

Title: Complex water engineering question
Post by: Tachytaenius on November 27, 2022, 06:58:54 pm
I have this complex water setup planned that will allow me to drain any cistern in the system for cleaning of contaminants.

Will water ever be able to flow up through the magenta arrow?
(https://i.imgur.com/vN1zOxr.png)

Someone already said "maybe if the caverns are completely flooded" and that makes sense, but otherwise?

Also, I have a well feed cistern because I feel like using diagonals to nullify pressure is a cheat. Just for my own worlds, of course.
Green arrows are pumps and blue lines are grates. The reason there is a pump (going up through a grate) for the moat thing drain is in to be building destroyer immune.
Title: Re: Complex water engineering question
Post by: anewaname on November 28, 2022, 10:48:38 am
To allow water off the map, it takes about 3 map-edge tiles to handle 7/7 water entering the system. Where the magenta arrow starts, it is important that junction has a vertical fall. Until the caverns below are completely full, pressured water will not be pushed sideways into the pipe underneath the farms. Most caverns have multiple off-map exits and a significant number of "empty" tiles, so you should be able to dump a river down that pipe without flooding the farms, because of that vertical fall at that junction.
Title: Re: Complex water engineering question
Post by: mightymushroom on November 28, 2022, 11:58:44 am
It looks like the moat is supplied by pump and emptied by pump, yes? My experience with pumping is that a pump teleports water to the "nearest" available location, it has no bias to go downward when a downward opening is available. So, it depends on how much water is in the moat, but I would identify a risk of flooding (at or higher than the magenta arrow) while emptying the moat.

And speaking for myself, I would be equally cautious with large-scale gravity draining elsewhere in the system. The previous advice about the main vertical plunge is true for that junction, because the pressure point where water falls onto other water is down in the cavern. I would worry, though, whether too much water becomes pressurized as it takes the first, shorter drain out of the well or well-feed cisterns onto the horizontal run. (I've not tried something exactly like this, but it would be consistent with my own understanding.)

That said, it looks like you already have enough control mechanisms (red bars are floodgates/doors/bridges, right?) to isolate one drain at a time. Keep those closed and they totally stop backwash. As shown here I think you're more likely to suffer operator error than design error.
Title: Re: Complex water engineering question
Post by: Salmeuk on November 29, 2022, 06:05:18 pm
be aware that unless you assist the water in it's off-map travel, the lag produced from flooding cavern open spaces is significant and tough to reverse.
Title: Re: Complex water engineering question
Post by: A_Curious_Cat on November 29, 2022, 10:11:01 pm
“assist the water in it's off-map travel”?

???
Title: Re: Complex water engineering question
Post by: Bumber on November 30, 2022, 03:11:35 am
“assist the water in it's off-map travel”?

Build an aqueduct/pipe to the edge of the map instead of dumping it into the middle of the caverns.
Title: Re: Complex water engineering question
Post by: Salmeuk on November 30, 2022, 03:16:33 am
“assist the water in it's off-map travel”?

Build an aqueduct/pipe to the edge of the map instead of dumping it into the middle of the caverns.

exactly. as previously mentioned, 3 edge tiles should take care of 7/7 consistent flow
Title: Re: Complex water engineering question
Post by: Blue_Dwarf on December 01, 2022, 12:58:59 pm
“assist the water in it's off-map travel”?

Build an aqueduct/pipe to the edge of the map instead of dumping it into the middle of the caverns.

What if his map freezes in winter?
Title: Re: Complex water engineering question
Post by: Salmeuk on December 01, 2022, 04:19:48 pm
freezing only matters on the surface. just build underground tunnel to "off map" via carving fortifications in the map edge tiles, which are normally un-diggable
Title: Re: Complex water engineering question
Post by: Bumber on December 01, 2022, 04:45:09 pm
freezing only matters on the surface. just build underground tunnel to "off map" via carving fortifications in the map edge tiles, which are normally un-diggable

If he considers diagonals a cheat, this is definitely a cheat (and a bad idea for visiting in adv mode.) Easy enough to just drop it downwards after reaching the edge, and you can use drawbridges as walls to make sure it doesn't flow away from the edge.