Again, this all depends how wide the Pelóri are. Taniquetal is, of course, huge, but if we're making the Calacirya a very long gap in the mountains...Taniquetal would have to be on the Western side, not the Eastern side. At least, that's how I showed it on my sketch.
For the purposes of this episode, though, the real question is the bounds of Melkor's probation, and whether or not he is permitted onto the slopes of Taniquetal in his vague 'stay in Valmar' restriction. If he can't leave the plain, he can't build whatever dam/pumped water system we were planning. Which requires me to come up with a new civic project.....