1. The Hrap River to the Krandai River of Ethengar and ultimately to the Streel and Malpheggi
2. The Kur River to the Vestfjord River of Vestland
3. The Klintest River to the Landersfjord River of Vestland
Some maps show all three rivers as outflows to the sea. Some show either the Kur or the Klintest as inflows, not crossing the mountains to Vestland. All maps agree that the Hrap river flows out to Ethengar.
Realistically, there should be only one river flowing out. This is a common but annoying world-building mistake. Water will choose the lowest course, that course will have the strongest flow and the fastest erosion, and eventually capture the entire outflow. The only way multiple rivers could drain the same lake is either (1) temporarily to drain excessive lake volume, or (2) some mechanism that prevents erosion. Also, three outflows are excessive for a lake with only two inflows; it could be draining faster than it is filling.
Has anyone dealt with this by altering the maps, or else explained it in some way?
- One river is connected by a canal with locks. It is not a natural watercourse. That would establish a major trade route through the mountains. I know some have suggested this for the Kur/Vestfjord river, and it also parallels a highway; but if the dwarves went to so much trouble to build a canal to Vestland, why not also build a canal from Evemur to Smaggeft? Such a canal would connect the two great lakes and benefit internal transport, and it also seems less work than a canal to Vestland.
- Maybe the dwarves dammed the Hrap to raise the lake level, causing it to overflow through natural gaps to Vestland. Chaning water levels seems a bad idea in a kingdom riddied with tunnels that could easily flood.
- One river (either the Kur or Klintest) originates in the mountains, from a gate to the plane of water located atop a ridge. Water flows two directions, into Rockhome and into Vestland. These rivers need not be level, and would flow down both sides of the ridge.
- Klintest was once an icecap, and at least three glaciers flowed out where the rivers are now, creating deep valleys.
- Klintest is fed by a water elemental gate. The dwarves maintain three stable outflows to prevent the eastern half of the kingdom from flooding.
- Instead of an elemental gate, maybe Klintest is fed by stray water magic conjured by the elves, a side effect of the greening of Alfheim?
- Maybe the Klintest Monster likes to dig?
Klintest was once a simple mountain lake that drained through the Klintest River. The Kur flowed in, and there was nothing where the Hrap is now. The Klintest flows through a narrow and deep gorge with many cataracts. (The gorge was formed by a glacier, earthquake, or whatever.) There is a natural gap in the mountains at Evekarr and the road takes advantage of it, since the Klintest is impassable and prone to rockfalls.
At some point a water gate opened in the lake and it began to fill. The Klintest river swelled, but could not expand in the narrow gorge, so got deeper and more violent. Heavy erosion in the Klintest Gorge caused a landslide, partially blocking it and causing further backup. As a result the lake rose until Kurdal and Smaggeft were threatened with flooding. To prevent this, an overflow channel was created north into Ethengar to protect the cities. It was successful, and since it is cut in bedrock there is no serious erosion. It was expected that the Hrap would dry up in summer, but there proved to be sufficient flow to create a navigable river year-round.
Wanting to export heavy ore to Vestland, and import bulk foodstuffs, the dwarves built a canal with locks through the Evekarr Gap. Additional locks on the Hrap allow riverboats to travel by an inland route from Vestland to Ethengar. Were it not for the broken lands, riverboats could make it all the way to Athenos and Akesoli. The king of Rockhome would love to capture and tax the inland trade route.
Just batting around ideas. My inclination is to block the Klintest and the Kur, so that the only outflow is the Hrap.