he was conditioned to think that way thanks to his old toxic workplaceBreed might be one of the bigger losers in the genre. It's not totally uncommon for the protagonist to be forced into an accidental promise for a big project beyond their current means. Breed is only the one that's such a huge loser he thinks if he doesn't complete a decades long project in a day he'll be bad mouthed. There's no way with their level of technological development that the people think of this as anything less than a years if not decades long project. Even after finding a source for the river it would probably take years to scout and determine the path the river should take let alone dig that route.
Heroine's ass-shot has a whole other meaning due to that title lolThat chapter title was hilarious.