40d Talk:Underground river

Assuming that there's some logic behind underground river locations, it seems to me that the following might be good places to look: 'Upstream' from the source of a regular river (perhaps that river doesn't start there, but that's simply where it makes it to the surface first), in an area without many visible surface rivers (rain falls and has to go somewhere), and in areas with lots of limestone, which is where a lot of real-world underground rivers are. NPComplete 13:18, 4 December 2007 (EST)

It is in my understanding that underground rivers spawn cave fish. Also, above ground rivers channeled under ground do not spawn cave fish. Can someone verify this? --Flaa 12:55, 22 April 2008 (EDT)

As far as I'm concerned creatures spawn only in respectable biomes. When you channel to cave river this biome does not extend up. It cannot be extended in any direction. If you could block flow of the cave river you could make small pond, from which cave fishes could travel up the channels to the aboveground river, but they will never spawn there.--Someone-else 14:38, 22 April 2008 (EDT)

In the current version (38c) underground river creatures do get caught in cages. I can verify this, I have a pit full of cave crocodiles, and I've caught numerous lizardmen. -- Lotus 9:58, (CST) June 11, 2008

Flooding

Do cave rivers still flood seasonally like in the 2D versions? Extar 15:11, 30 August 2008 (EDT)

Odd River

I have a very... odd river. It starts out as mist, in the middle of nowhere, and counts as a waterfall, then it goes on for a screen, then falls off a chasm. http://s4.tinypic.com/6sgi90.jpg The entire area 1z above is empty space the same size as the river. Then above that, rock. Where is the water comming from? It's mildly amusing, because random underground river creatures will spawn in it, swim around for a while, then fall into the chasm.

A underground river tends to start within pure rock without any "real" reason. My actual map has one starting this way, too. It´s not as odd as yours. It goes south, then 1 z-level down, then nort-west, then down again, then east... There are five of these short parts before it goes down a chasm. I think this is normal when it doesn´t come from the edge or leaves the map.--Kami

(I hope I'm doing this right. First comment.) My map has a river. It starts as the odd river described, a 'waterfall' which doesn't fall. From there, it travels west southwest for quite a ways, then has a sharp bend, to northwest, for a short way, and then it falls several Z-levels. After that, it travels north for a ways, then drops several more Z-levels, to a chasm. --wattj 15:43, 31 January 2009 (EST)

Underground rivers can spawn anywhere, essentially. They are created by a special tile-type that creates water out of thin air. My most interesting underground river started at the very edge of the map, in the middle of a chasm, which meant the water just fell straight down into the chasm. It looked pretty funny. -- j0nas

Every one of your underground rivers fell into a chasm. Do they all have this attribute in DF?--Richards 21:19, 10 August 2009 (UTC)

Nothing "odd" about how these start - that's textbook if your map encompasses one or both ends of an UG river. (If they seem to "go off the map", then you are not seeing the actual start/end of the feature.) As for the "chasm", I believe that is also the case, yes - it's how the feature seems to terminate at the down-river end. Not an actual, proper chasm in that technical sense, but something close enough.--Albedo 21:25, 10 August 2009 (UTC)

Do to underground rivers still spawn creatures in 40d?

All the frogmen and giant olms on my map fell into a bottomless chasm. Will I ever see one again? Or, like regular chasm creatures, do they never replenish in 40d?--Jpwrunyan 05:31, 13 August 2009 (UTC)

No. --Birthright 09:55, 18 August 2009 (UTC)

+1. Have no idea what you mean by "regular chasm creatures" - no creature ever "spawns", only vermin.--Albedo 17:09, 18 August 2009 (UTC)

Except for wild animals, which reportedly will migrate onto your embark region from the map edge (though I haven't had the opportunity to observe such behavior). --Quietust 21:09, 18 August 2009 (UTC)

Migration occurs, but it's not "spawning", which is the sudden appearance of the (fully grown) vermin/fish anywhere - not entering from a map edge. Vermin (and fish that fall into that category) have no "young". Creatures do.--Albedo 22:24, 18 August 2009 (UTC)

Just to clarify, regular chasm creatures = creatures that regularly appear in chasms (trolls, gremlins, batmen, etc.). Anyway, thanks for answering my question.--Jpwrunyan 13:30, 17 October 2009 (UTC)

A RL example of an underground river. Fascinating

Mexican underwater river