LazarusLong42
First Post
Barcode said:Bummer. So you are saying that the elevation of the river basin stays below 600 ft for 100 miles across? Not that a 100 mile dam is impossible in a fantasy world. Could be quite stunning, actually.
Well, it's not that exactly... I guess what I'm saying is that water, like electricity, will take the path of least resistance. If you dam a river to elevation X, the water will first flow over the dam, but as water starts to rise behind the dam, it'll look for other ways out and down.
If the dam is inside a channel--take, for example, Hoover Dam--the water wouldn't be able to flow around the dam, because it's still hemmed in by the channel. But to dam a river with a very shallow channel, which the rivers of the St. Lawrence Seaway are, the dam has to be very wide. It would have to connect two points that would each be 600 ft. in elevation, with increasing elevation as you went away from the dam. That would force the water to stay in the (very wide) channel.
For the record, 100 miles was very much a guess. As I look at a map again, it's probably not more than a few miles actually. Still a very large dam--and it would have to cross the Welland Canal too.
Not to mention withstanding 10000 years of erosion. I'm thinking a large number of mages casting permanent walls of force...