Chakravanti wrote:based on the fact that there is no concievable method of implementation. I still say make it a building.
So taking off this idea, suppose canals were constructable like walls. They are a new type of tile has the properties of shallow water for movement, but digging in them produces no resources. Likewise, canal tiles do not spawn curios or fish. Water can be collected from them, but it is always q10. Canals can not be built in mountains. Canals decay back to their original tiles over time if not on claimed land.
The initial "cornerpost" would have to be built adjacent to shallow water or another canal tile. It could cost something like 200x bricks + 50x stone + 5x bone glue, with subsequent "cornerposts" being 50x bricks + 10x stone + 1x bone glue and each section 5x bricks. Give it 2000 HP and 15 soak. Sledgehammers and rams would not be useful for destroying canals, but pickaxes give +2 damage and shovels give +4 damage against them. A destroyed canal piece reverts back to its original tile.
This way, canals provide basically no resource benefit; they're just for transportation or possibly moat building.
As far as usefulness as a defensive structure, with only 15 soak, anyone with 225+ strength could break them, and only 121+ if you bring a shovel. In most cases, a canal would be easier to destroy than a palisade.
For griefing potential, someone could be a jerk and build canals over your hq acre clay or soil nodes, but this would be way more trouble than just digging it up. Plus, the tile would revert to normal if you can destroy the canal. Griefers could try to create a waterworld, but the materials cost can be set to make that infeasible and the canals would decay on unclaimed land.
On the other side of the griefing scale, it would be pretty easy to make a strength alt and run around destroying everyone's canals. You could make it possible to build gates on canals, and brickwall or palisade around them i guess. There's always the solution of claiming the land and tracking them down afterward as well.