|
The heroes can fire off one use of the Pit Fiends to drain the dam, but will the dam be jammed after that (open or shut)? Will the people of Turtleback Ferry have to establish a presence at the dam, including a small farm to provide sacrifices for the dam?
When was the pit fiend last drained? could a Greater Restoration get him a hit dice back?
The heroes can fire off one use of the Pit Fiends to drain the dam, but will the dam be jammed after that (open or shut)? Will the people of Turtleback Ferry have to establish a presence at the dam, including a small farm to provide sacrifices for the dam?
When was the pit fiend last drained? could a Greater Restoration get him a hit dice back?
The pit fiend was last drained 54 years ago, the last time the dam was activated. The other pit fiend died and turned to dust at that time. That is pretty far outside the time limit (one week per caster level) of Greater Restoration.
Farm animals aren't a bad idea for triggering the mechanism.
As far as I can tell, Volume 3 of RotRL expects the PCs to release the pressure in the dam once and then forget about it. I would guess that if Karzoug succeeds in rising then he'll fix it by binding two new pit fiends inside, but that's probably not considered a happy ending.
I don't see an easy solution to this. Odds are good that the dam will be pit fiend-free by the end of HMM, and the dam was already badly damaged in that scenario already. If the PCs ignore the issue they risk the flooding of half of Varisia, but if they do the problem justice then that's looking like a really big undertaking with no victory in sight.
If we ignore the problem will it go away? :)
I'm not an engineer, and I could be wrong about this. The break strikes me, though, as something that would weaken the overall structure. Formerly there was this arc that was anchored at both sides, and it held back the entire Storval Deep, which is why places like Ilsurian and Whistledown can exist at all. Won't the damaging of the dam hasten its crumbling?
|
Yeah, most damns have an "overflow" (sluiceway?) to releive pressure should the valving malfunction or the water rise faster than they can handle. Given the damage to the damn, I would assume that
1. The lake would be slightly lower than in the past.
2. The river to Turtleback Ferry would be more prone to flooding (the default opening in the damn kept the flow 'normalized'. Now, during "high water" seasons, the river will grow.
3. Erosion of the damn through the damaged portion *MAY* further weaken the structure, but I would just make this a gradual effect. Over the coarse of a hundred years or so it wears down, lowering the lakes level, widening the floodplain, etc.
4. Since none of this overly effects RotRL or presumably any Pathfinder in the near future (I doubt Paizo will advance the timeline by 100 years or so) its really not an issue.
Basically, ignore it.
Yeah, most damns have an "overflow" (sluiceway?) to releive pressure should the valving malfunction or the water rise faster than they can handle.
So given that I have an engineer (IRL) in my group, how do I describe this overflow? My guess is that he's going to be looking for it, even if his character isn't. Would it be away from the dam itself, maybe somewhere off to the east?
Creative Director
|
Eventually, the dam'll need fixing. That's a long term goal, though, since it only ever floods so much that it needs fixing once or twice a century. Plenty of time for Varisians and PCs to find a solution and fix it (or plenty of time to procrastinate).
The overflow itself is mostly internal; it outflows at the base of the dam and is largely unseen from outside. The PANIC overflow is the part of the dam that's broken, and what needs to be fixed by the PCs in the adventure.
Thanks! I suspect that the long-term stuff is mostly going to matter to PCs who actually take over the fort.
Kyra initiated what will be a ritual routine of sending strong and hearty petitioners to volunteer to enter the circles with restoration scrolls already prepared for the next crisis when it might arrive.
I like the animal sacrifice idea as well.
As it is, I'm still curious how the next installments refer back to any prior locations now that the heroes have increased in power and fame. They made a lot of excellent ties, and I'm keen on how anything might change.
|
|
| 1 person marked this as a favorite. |
Another point to consider: there's something in The Storval Deep that really likes dirt. Ten millenia of runoff from three rivers means that it was unrealistically deep to begin with, or something must very efficiently convert mud and silt into heat, light, neutrinos, ducks, huge flocks of fish-eating wyverns (that know to leave their droppings downstream of the Deep)*, or something else not easily contained in a lake; or maybe Golarion's spheres of annihilation were ancient Thassilonian mining tools. Seriously, the Banqiao flood was partly due to silt (and bad communications) and the dams there failed after only a couple decades or so. As world features go, Skull Dam is cool, but fantastic, rather than realistic.
Maybe the reason the gnomes of the Sanos are so secretive is because they know that Skull Dam has got to go, so that the Mushfens &c. don't all get nibbled away by the sea, and their druids have begun planning about how to make that happen. Or maybe they're in charge of the flup pipeline at the bottom of the Deep that's giving all that mud a bypass around the dam.
*My own theory is that the Wyvern Mountains must have been built up of dire freshwater mussel shell middens from the eponymous predators.
That's an interesting angle, logic poet. As a damn, I would think that druids and Gnomes would view the infernal device as obscene. The trolls and the Ettin could have been a major hindrance before, but now after it's cleared, perhaps something might happen.
I was half tempted to use the whole *Yap gets the PC's to the Shimmerglens* as a massive decoy while Druids and Gnomes and other volunteers use their combined forces to obliterate the damn.
I won't, but I am very tempted.
If the gates remain open, that might help the dam. If the water level goes below that level of the damage made by the ogres, then the water will stop pouring through and the dam won't have to put up with the force of the erosion.
Yeah, but look at the size of that lake. That's a lot of water to suddenly add to the Yondabakari valley. The water stains on the front of the dam make it look like more than half the height being held back would be drained, which is going to make a pretty big impact on the ecosystem behind the dam and (in the short term) flood a lot of stuff along the river (and possibly Lake Syrantula).
Or am I misunderstanding the situation?
No, tbug, I think you're right. Destroying the dam all at once would be an extremely bad idea, even for rabid druids. Say good bye to the Shimmerglens and Turtleback Ferry. Chunks of the Sanos Forest and the Ashwood would probably be hit. All the towns along Lake Syrantula and the Yondabakari would probably get flooded. The water might even reverse the flow of the river out of the east end of Lake Syrantula. And sections of the Mushfens would probably get disrupted as well.
Now, if you had a bunch of high level druids who were willing to take their time, they could probably slowly lower the dam and control the water and stuff so that there wasn't a lot of destruction. But it might take a long time. And it would only be possible because whatever original magical protections were there have faded with time.
So if the gates are just left open, how quickly will the water level of the lake drain? Will that be slow enough to prevent widespread change (other than having a much smaller lake behind the dam)?
|
|
If the gates remain open, that might help the dam. If the water level goes below that level of the damage made by the ogres, then the water will stop pouring through and the dam won't have to put up with the force of the erosion.
This does not address the point I was trying to make. If you look on the regional map, you'll see three rivers that drain into the Storval Deep. One comes from mountains, and the other two come across distances. Along the way, they pick up dirt. Since the dam blocks most of the water (as is its purpose), most of the dirt stays behind. Basically, the Deep is a settling tank. Imagine a pitcher of lemonade, into which you pour damp sugar. Even if you have a few glasses, eventually, the pitcher won't disolve the sugar and it will drop to the bottom. In the particular case, an accurate map of the region from 10,000 years ago would have to have read "The Storval Deeper," relative to the situation today.
|
|
No, tbug, I think you're right. Destroying the dam all at once would be an extremely bad idea, even for rabid druids. Say good bye to the Shimmerglens and Turtleback Ferry. Chunks of the Sanos Forest and the Ashwood would probably be hit. All the towns along Lake Syrantula and the Yondabakari would probably get flooded. The water might even reverse the flow of the river out of the east end of Lake Syrantula. And sections of the Mushfens would probably get disrupted as well.
...
Longer term, Magnimar would probably go into decline, as there's no guarantee their river is the going to continue flowing to them, instead of along a new route the Deep's outflow might cut.
As for the rabid druids, I disagree. Some of them might argue for a sharp, shock, which would have only a brief interval of adjustment. On Earth, there exist plant species that require disasters; for instance, some seeds germinate only after being weakened by fire. Coconuts, as a species, benefit from storms and hurricanes because though the trees might lose all their leaves, or even die, the disruptions in regular sea currents tends to spread their seeds to places they wouldn't have gone.
|
|
| 1 person marked this as a favorite. |
After further thought on the Storval Deep mud problem, I've concocted the following crazy ecosystem:
The three rivers add soil to the deep. This brings nutreints to the single celled algae. Some of them get eaten by fishes, and so on up, but for whatever ancient accident, the real beneficiaries have been filter-feeding dire freshwater mussels, of which the Deep has multitudes (since the disolved minerals in all that dirt help them build their shells, I guess). One of the few predators of the mussels are the wyverns, which roam in flocks much larger than suggested by the SRD number appearing. They range over the Deep, dive down when they see mussels they think they can take, and use their poison and strength to pry the mussels up from the bottom. Only the weak and desperate wyverns attack humanoids, since the humanoids carry missile weapons, and generaly are too small too be worth the effort, compared to the mussels. Likewise for the giants and ogres. Then they fly over the Wyvern Mountains and drop the mussels from a height sufficient to kill and crack the shells open to get at the flesh within. As a result, those mountains are giant middens of compacted mussel shell, perhaps on top of some original hills of hard rock that started it all. Because the Wyvern Mountains are made in large part of shiny, iridescent nacre, and because they are immune to poison, the top predators of the region are amethyst dragons. The younger than juvenile ones use their superior intelligence and burrowing speed to steal wyvern eggs, while older amethysts hunt live wyverns via crocodile style drownings using their swim speeds and superior Con scores; breath weapon based hit-and-runs in flight using their superior fly speeds to avoid being mobbed by the numerically superior prey, and psychokinesis. Too bad the gem dragons aren't open content.
|
|
Wasn't the Storval Deep originally a mine? A Runelord mine?
Somewhere down there is a golem, digging and digging, at a rate almost identical to the accretion of silt.
Silting up will be a problem if the golem breaks, but the bigger problem comes in another 10,000 years when it reaches the planet's core...
LogicPoets solution is better, but mine's more convenient.
|
|
If the dam breaks, I would rule a much larger Lake Syrantula in the short term, with the destruction of all the communities on its shores, as well as Turtle Back Ferry. White Willow and Pendaka would also be destroyed (and countless other settlements along the river between Claybottom and Syrantula. The residents of Bitter Hollow would soon have to relocate, but I don't think the devestation would strike them as quickly as the down river communities.
Eventually I think the water would flow south and west forming a secondary lake in the shimmerglens and a tertiary lake in the northern Mushfens. Magnimar would see major flooding for a year or so but the waters would eventually reside to their original levels.
The Storval deep would be reduced to half of its original size, revealing many lost mines and catacombs.
As for the silt - perhaps the Storval Deep was originally twice as deep and now there is a dangerous layer of muddy goop at its bottom. A real peril for incautious underwater explorers.
Wasn't the Storval Deep originally a mine? A Runelord mine?
IIRC, it was a quarry.
If the dam breaks...
There are some nice Wikipedia pages on dam failure
After further thought on the Storval Deep mud problem, I've concocted the following crazy ecosystem:
Spoiler:
The three rivers add soil to the deep. This brings nutreints to the single celled algae. Some of them get eaten by fishes, and so on up, but for whatever ancient accident, the real beneficiaries have been filter-feeding dire freshwater mussels, of which the Deep has multitudes (since the disolved minerals in all that dirt help them build their shells, I guess). One of the few predators of the mussels are the wyverns, which roam in flocks much larger than suggested by the SRD number appearing. They range over the Deep, dive down when they see mussels they think they can take, and use their poison and strength to pry the mussels up from the bottom. Only the weak and desperate wyverns attack humanoids, since the humanoids carry missile weapons, and generaly are too small too be worth the effort, compared to the mussels. Likewise for the giants and ogres. Then they fly over the Wyvern Mountains and drop the mussels from a height sufficient to kill and crack the shells open to get at the flesh within. As a result, those mountains are giant middens of compacted mussel shell, perhaps on top of some original hills of hard rock that started it all. Because the Wyvern Mountains are made in large part of shiny, iridescent nacre, and because they are immune to poison, the top predators of the region are amethyst dragons. The younger than juvenile ones use their superior intelligence and burrowing speed to steal wyvern eggs, while older amethysts hunt live wyverns via crocodile style drownings using their swim speeds and superior Con scores; breath weapon based hit-and-runs in flight using their superior fly speeds to avoid being mobbed by the numerically superior prey, and psychokinesis. Too bad the gem dragons aren't open content.
I put the vast majority of your (clever) post in tags, so as not to spam the board.
Alternate ideas: It has already been established that there are several tribes of giants (Stone, Hill and otherwise) that call the lake and surrounding areas "home." Rather than massive flocks of wyverns, why not have the giants be the chief consumer of mollusk?
Also, I believe that common top-level predators (in the real world) include: wading birds, alligator, otter, mink, and raptors. I know that in this case, raptors refers to birds of prey, but there are other possibilities.
Further information presented here might be useful, esp. the blurb about Anomalodesmata.
|
For a simpler (though less clever as well) solution, couldn't we postulate a Thassilonian construct dredger still working the bottom of the Deep, moving accumulated silt elsewhere, perhaps to locations on the shoreline somewhere? We know that Karzoug was pretty excited about his dam, and you know when he made it he would have been expecting him and his empire to last for millenia yet... he'd've thought ahead on this.
|
|
If it keeps on rainin, levees goin to break,
If it keeps on rainin, levees goin to break,
When the levee breaks Ill have no place to stay.
Mean old levee taught me to weep and moan,
Lord, mean old levee taught me to weep and moan,
Got what it takes to make a mountain man leave his home,
Oh, well, oh, well, oh, well.
Dont it make you feel bad
When youre tryin to find your way home,
You dont know which way to go?
If youre goin down south
They go no work to do,
If you dont know about chicago.
Cryin wont help you, prayin wont do you no good,
Now, cryin wont help you, prayin wont do you no good,
When the levee breaks, mama, you got to move.
All last night sat on the levee and moaned,
All last night sat on the levee and moaned,
Thinkin bout me baby and my happy home.
Going, gon to chicago,
Gon to chicago,
Sorry but I cant take you.
Going down, going down now, going down.
Robert Plant Meets RotRL #3
|
Creative Director
|
Wasn't the Storval Deep originally a mine? A Runelord mine?
Somewhere down there is a golem, digging and digging, at a rate almost identical to the accretion of silt.
Silting up will be a problem if the golem breaks, but the bigger problem comes in another 10,000 years when it reaches the planet's core...
LogicPoets solution is better, but mine's more convenient.
Yup; the majority of the monuments in Varisia were built out of stone quarried from the Storval Deep; Karzoug flooded the immense quarry once all the "good" stone was played out.
No, tbug, I think you're right. Destroying the dam all at once would be an extremely bad idea, even for rabid druids. Say good bye to the Shimmerglens and Turtleback Ferry. Chunks of the Sanos Forest and the Ashwood would probably be hit. All the towns along Lake Syrantula and the Yondabakari would probably get flooded. The water might even reverse the flow of the river out of the east end of Lake Syrantula. And sections of the Mushfens would probably get disrupted as well.
...Longer term, Magnimar would probably go into decline, as there's no guarantee their river is the going to continue flowing to them, instead of along a new route the Deep's outflow might cut.
As for the rabid druids, I disagree. Some of them might argue for a sharp, shock, which would have only a brief interval of adjustment. On Earth, there exist plant species that require disasters; for instance, some seeds germinate only after being weakened by fire. Coconuts, as a species, benefit from storms and hurricanes because though the trees might lose all their leaves, or even die, the disruptions in regular sea currents tends to spread their seeds to places they wouldn't have gone.
Ra's al Ghul starts a great line about when the forest grows too wild . . .
My wife found it irritating.
I can also see rabid Druids doing it, perhaps they have their INT as a dump stat.
It would make a great side trek.
I don't think the silting up of the Storval Deep is really much of a problem. Giant dire mussels are cute, but I don't think you need to create a complex ecological or magical silt removal system.
The Great Lakes of North America have been around since the last Ice Age, and they haven't silted up yet. Each lake is very deep, but the connections between lakes are much shallower than the lakes, and there's all sorts of man-made improvements (locks, canals, etc.) So I don't think you can assume that 100% of the silt that enters each lake eventually gets to the Atlantic Ocean.
Lake Ontario looks to be about twice as big as the Storval Deep in surface area. It has a volum of nearly 400 cubic miles with an average depth of 283 feet and a max depth of 800 feet. So the Storval Deep could have 200 or more cubic miles of water volume, depending on how deep the quary went.
No matter how many rivers drain into it, a cubic mile is a lot of silt.
"If you drain it, silt will come."
"If you drain it, silt will come."
O_o
Hmmm....Right. Definately one of your more, uh, concise posts.
Giant dire mussels are cute,
Fear the Dire Scallop!
|
|
...
The Great Lakes of North America have been around since the last Ice Age, and they haven't silted up yet. Each lake is very deep, but the connections between lakes are much shallower than the lakes, and there's all sorts of man-made improvements (locks, canals, etc.) So I don't think you can assume that 100% of the silt that enters each lake eventually gets to the Atlantic Ocean.Lake Ontario looks to be about twice as big as the Storval Deep in surface area. It has a volum of nearly 400 cubic miles with an average depth of 283 feet and a max depth of 800 feet. So the Storval Deep could have 200 or more cubic miles of water volume, depending on how deep the quary went.
No matter how many rivers drain into it, a cubic mile is a lot of silt.
Yes, but unlike Lake Ontario, the Deep has been dammed for 10,000 years. To give a different real-world example, at the end of the last ice age (8,000 years ago), the Mississippi entered the sea at Baton Rouge, 60 miles inland from its current outlet. Further research on my part indicates that the sediment load varies with the seasonal variation in flow, but averaged over the year, is about 300 million tons, and that dirt is about 125 lb/cu. ft. Doing the math and converting units, I get an annual load of about 0.0326 cubic miles per year. At that rate, it would take the MS only about 6,135 years to deliver 200 cubic miles of dirt. Now the tributaries of the Deep are shorter than the whole Mississippi system (including all tributaries, like the Red, Platte, Misouri and Ohio rivers), but given the terrain they run through, they're probably at least as silty. So the volume of silt is much less, but the time is longer. Even if the volume is a tenth of the MS, Skull Dam could have lots of silt against it, depending on the topology of the bottom.
The Storval Deep watershed is tiny compared to "Old Man River". The Mississippi drains a large part of North America, with a drainage basin of 1.245 million square miles according to wikipedia. Judging from the map, the Storval Deep is probably only 50K to 60K square miles. So the Storval basin is only about 1/20th or 5% the size of the Mississippi.
Also, if the rainfall in the area averages less than what you get in North America, there would be proportionately less flow into the lake, and therefore less silt. I wouldn't be surprised if the area was drier.
I have no idea how we could figure out if the land is more or less silty. It's not like we have a lot of geology information. It probably averages out to be about the same, but who knows?
Whether or not there is any silt against the dam would depend on how far down Karzoug dug his quary before he built the dam. And how deep the rift was when he got there. Some of the quary could go way below the level of the bottom edge of the dam. Or maybe more of the digging was "sideways". Whatever.
Anyway, it seems to me that you can make a compelling argument that the potential silt problem isn't big enough to require a complex explanation. It doesn't break my "suspension of disbelief".
The whole "Dastardly Dam Destroying Druids" idea is an interesting hook (and alliterative), but not something I'd want to mess around with. Because if the Druids succeed, you have to re-do a quarter of the map. Seems like a waste of time to me. Why throw out stuff that paizo wrote if you don't have to? I would rather spend my time on other things.
|
Look at Lake Tahoe in California. It has over 60 major stream tributaries and almost no change in depth or silt coverage(although the massive casinos on its south shore has stirred up the lake to make it murkierthan it was 100yrs ago, science has not idea what this will do to the LLLOOONNNNGGGGG range picture for the lake). Its no "great" lake but has many of the same problems presented by yall of the Deep. Science's best guess is that in about 10,000 - 20,000 years will pass before it is transformed into verdant pasture land from the sediment, the granite sediment of the Sierra Nevada Mts. Lake Tahoe is about 1 mi across and 2 mi long, no back story or crazy ecology needed, water is pretty danged good at breaking down even the toughest dirt. Plus most tributaries that feed large lakes have excellent pasture land surrounding the mouth of them due to the serious amount of excellent dirt filtered through the lowland plant life that surround the streams and rivers that feed it.
Although I like the giant mussels idea......
|
|
Although I like the giant mussels idea......
Thanks. I've been looking for something to do justice to the Amethyst Dragons since their lairs are supposed to be glittery. Also, shell midden archaeology is cool. Most of the Wyvern mountains are probably quarry tailings (or whatever the term is for quarries instead of mines).
For the record, I would also point out that one of the three rivers involved with the Deep appear to be flowing out, not in, and going through the mountains to merge in the lake below the dam. So some of that silt is likely spilling right on out and away.
Do you mean the one that flows through the Iron Peaks? I disagree with your interpretation, if so. It looks to me like that one flows out of the Peaks and into the Deep, while another, separate river has a source very near to its but flows to join the Skull River past Turtleback Ferry.
I could, of course, be wrong. :) Anyone have anything authoritative to add?
The heroes can fire off one use of the Pit Fiends to drain the dam, but will the dam be jammed after that (open or shut)? Will the people of Turtleback Ferry have to establish a presence at the dam, including a small farm to provide sacrifices for the dam?
When was the pit fiend last drained? could a Greater Restoration get him a hit dice back?
As interesting as this thread as been, I think a solution to resolving the dam issue needs to be more of a character based one. Just say at clan of engineer dwarves from Janderhoff have found out about the dam and see it as an opportunity to test they abilities and stick it to the giants in the region.
If you haven't got to this part in your campaign, create a likable dwarven or other type of engineer character that is part of a guild (create one) that the party meets in either Sandpoint or Magnimar. It gives your players a future resource that they can call on to work not only on the dam, but also help rebuild Fort Rannick if the group decides to maintain control of the fort. It could make for some good gaming.
What if the dwarves find out that below the waters of Storval Deep there are rich resouces? Throw in some "2,000 Leagues under the Sea" and you have some underwater mining dwarves. It might be some nice flavor.
What if the dwarves find out that below the waters of Storval Deep there are rich resouces? Throw in some "2,000 Leagues under the Sea" and you have some underwater mining dwarves. It might be some nice flavor.
Dwarves in diving bells and deep sea dirigibles being besieged by Dire Scallops? Awesome.
<snip>The whole "Dastardly Dam Destroying Druids" idea is an interesting hook (and alliterative), but not something I'd want to mess around with. Because if the Druids succeed, you have to re-do a quarter of the map. Seems like a waste of time to me. Why throw out stuff that paizo wrote if you don't have to? I would rather spend my time on other things.
Well, that's just way too sensible.
Dwarves in diving bells and deep sea dirigibles being besieged by Dire Scallops? Awesome.
What if the dwarves find out that below the waters of Storval Deep there are rich resouces? Throw in some "2,000 Leagues under the Sea" and you have some underwater mining dwarves. It might be some nice flavor.
I agree. I wouldn't miss that BBQ for all the puns of Bullwinkle. It's been so long since I've had raw oysters either. I make a mean seafood quiche myself.
On maintaining the emergency spill way power, since the PCs will be fairly high level by the end of RotRL, they could contrive something more magically advanced then a sacrificial fish farm. Going a little outside of the rules, but I would think any planar mage with a decent wisdom score should be able to figure out a way to tie the Plane of Positive Energy directly to the gate mechanism. Would it be expensive and costly to the PCs? More then likely as I guess such a permanent power source would conservatively cost close to a million gold and require a fairly heavy expenditure of experience points.
If I know my group RotRL isn't going to be about the return of the old Rune Lords but the rise of new ones, the PCs.
|
|
The Storval Deep watershed is tiny compared to "Old Man River". The Mississippi drains a large part of North America, with a drainage basin of 1.245 million square miles according to wikipedia. Judging from the map, the Storval Deep is probably only 50K to 60K square miles. So the Storval basin is only about 1/20th or 5% the size of the Mississippi.
...
Whether or not there is any silt against the dam would depend on how far down Karzoug dug his quary before he built the dam. And how deep the rift was when he got there. Some of the quary could go way below the level of the bottom edge of the dam. Or maybe more of the digging was "sideways". Whatever.
...
I took a ruler to the visible part of the rivers upstream of the deep, and roughly estimate it at about 40,000 sq. miles, so your analogy is strengthened. For the Storval river, I estimate the length at about 200 miles and that of the Kazaron plus Stalak, at least another 500 or so, plus whatever's off the map. That's about half the length of the Ganges, and from various descriptions, it sounds like the Kodar mountains have a fair bit of snowmelt to contribute.
In addition to less rainfall, drier would increase loss due to evaporation, as well.
The amount of silt against the dam also depends on the topology of the bottom of the deep, as you say. You're implicitly assuming that the deepest point is in the center, like an inverted wedding cake. This is one fair assumption for a former open pit mine, but not the only possibility. It could also have been the case that the mine is a widening of a gorge between the Iron Peaks and the Wyvern Mountains, in which case the topology would serve to channel stuff right up against the dam. (kind of hard to describe exactly what I mean, but if you think of wedges in 3-d, that's what I'm aiming at.) Much also depends on how many rivers are running through the Iron Peaks. Most of my original complaint is that it appears there are 2, one of which drains into the Deep. If there's only 1, and the Deep drains out that way, my complaint goes away.
Before the internet, who could have believed in armchair hydrology?
|
|
For the record, I would also point out that one of the three rivers involved with the Deep appear to be flowing out, not in, and going through the mountains to merge in the lake below the dam. So some of that silt is likely spilling right on out and away.Do you mean the one that flows through the Iron Peaks? I disagree with your interpretation, if so. It looks to me like that one flows out of the Peaks and into the Deep, while another, separate river has a source very near to its but flows to join the Skull River past Turtleback Ferry.
I could, of course, be wrong. :) Anyone have anything authoritative to add?
Thanks for this exchange; it clarified much of my thinking in my discussion with Michael F.
I'm feeling the submariner dwarves. Very nice.
I can't remember why I decided to look up the great lakes instead of Tahoe.
Anyway, this topic is so last month. ;^)
I just downloaded my PDF of Chapter 4, so we'll have to move on and find something to discuss there!
The heroes can fire off one use of the Pit Fiends to drain the dam, but will the dam be jammed after that (open or shut)? Will the people of Turtleback Ferry have to establish a presence at the dam, including a small farm to provide sacrifices for the dam?
This one's a bit long.
Short answer: Yes, but they intend to make it the Lord-Mayor of Magnimar's problem.So, my party is planning to put two trolls in the circles and then activating the dam. As for the future (I asked) they intend to make it the Lord-Mayor of Magnimar's problem.
We did spend some time talking about the dam and its use. Having the floodgates only opened once in 54 years, seemed a bit odd to me. So instead, I said they opened seasonally based on the amount of pressure behind the dam. As the rainy/winter season progresses, the dam opens and keeps the flow down the river equal. If the dam doesn't open, there'd have to be alternate flood channels elsewhere, otherwise the river would dry up. I said there were several beneath the dam that were only slightly open most of the time. The flood controls for these work the same way the others do (but aren't quite as obvious).
In my campaign we figured the flooding from a catestrophic dam failure would be bad all the way down to the lake below Skull river, but not much further - as the swamps there would flood more than the surrounding plains. With Turtleback ferry sitting so far away from the forest, I've described Turtleback ferry as being on a flood plain (with the road that leads to it being a popular ford in the dry season, but difficult to navigate now that they've had so much rain in the north). I elevated the Kreegwood, and lowered the Ashwood; which will give the road some protection (and explains why they built a bridge above the ford -- it's one of the few places where both sides of the river have an equal height).
With this logic, Claybottom lake can take a fair bit of flooding (and probably does seasonally). Turtleback ferry has a high-water mark (above which almost everything is built). Even the dock is built on a floating platform; and the ferries are flat-bottomed (to better deal with seasonally changing river depths).
But also, with this logic, the dam is expected to release fairly often; so without a power-source some other mechanism must be derived. My homework (for the next two weeks) is to try and figure out how long a troll would last in the circle. Unlike a pit fiend, trolls need to eat. But they can also consume themselves.
Edited to add spoiler.
This is an interesting fantasy engineering problem. If you're trying to repair the dam, why not have it after the PCs have attained a high enough level for Wall of Stone (cleric 5, druid 6, sorcerer/wizard 5)? The spell is shape-able, allowing a PC to fix the damage to the dam.
The magical power source is harder, of course. The magic circle for a greater binding is already there, and most devils and demons are immortal. Undead are immortal too - but are harder to keep unless you use the summoning magic circles specifically for that reason. The local farm sounds much easier to maintain, but it's going to be difficult to get all those animals down the stairs, correct?
When our group was considering short term repairs, we looked at both stone shape and wall of stone, and determined that neither was a practical solution prior to the flood controls being operated and even afterward it would involve a lot of spellcasting:
The walkway that runs the length of the top of the dam is 45' wide, bracketed by 5' wide 3' high safety barriers. That makes the dam 55' thick at the top. Once you get close to the breach, you estimate it to be about 50' wide and running maybe 75' down from the top of the dam.
Basic geometry will tell you guys as players that probably over 100,000 cu.ft. of stone is missing at the point of the breach. At Kestrel's level (9th) she could use wall of stone to create 37.5 cu.ft. of stone per casting or manipulate 19 cu.ft. of existing stone via stone shape. Further, a strict interpretation of wall of stone suggests that a single casting of the spell can't create a wall more than two inches thick -- since a block of stone 2' x 3' x 6.25' can't really be called a wall -- which would likely shatter immediately under the tremendous water pressure.
Similarly, transmute rock to mud is no good because it causes mud to turn into soft stone.
The magical dam controls didn't seem like a problem, as it's pretty much all automated. Much of the magic in the circles is just there to keep powerful creatures from leaving, but for most living creatures an ordinary cage within the circle will do. As mentioned, animals might be used. Even people can safely stand in as long as they have more than 1 HD each and access to a cleric who can cast Restoration.