Hi @Bettyboop55 !
Regarding your canal issue, I have a suggestion for you:
Maybe you could use the grand walls from Island Paradise as sides for the canal (they fit perfectly with the colour of the basic rocks and mountain terrain paint (the have some green mosslike stuff on them, but I think they can work as some greenery or seaweed) and then make a little space inbetween some of the walls, where you can put a lot for bridges, if you want some to cross it.
Hope it was helpful to you. I'm following your build, looking forward to seeing more!