Firstly can I ask what map you used to make the economic development plans? With the Westerlands plan, wouldnt it make more sense to link Hornvale to Blackwater rush? then you would have a direct link to KL rather then having to go via maidenpool?

Good question, tricky to answer. For geography, I tend to use Ser Mountain Goat’s map over the map book, because the scale in the former makes it easier to calculate distances and thus time b/w destinations, and I use either over the WOIAF maps which are execrable.  

So depending on which map you use, you have different depictions of the terrain, which shapes what kind of policy you’d prefer. For example, in the map book, a Stony Sept to Pinkmaiden canal or a Godseye to Trident Canal really looks quite easy. 

Hornvale to the Rush would be possible, although there may be issues about House Lannister building a canal on what is probably Tully land.