Glad I could help. Thinking a little bit further, you might want to cut down the width to either the 50 or 60 feet I mentioned or 80-100 feet. That higher figure would allow small vessels to be moored along the sides of the canals while traffic passed in both directions in the canal itself. It just depends on how important the canals are to traffic and transportation within Larano. For comparison, the Grand Canal in Venice is 80 to 175 feet wide. The side canals off of it, are nowhere near as wide.

I would recommend the same with your canals--have one large one (the north/south canal would be ideal for that) and "shrink" the smaller canals.

Remember, these canals were dug with human/horse/ox power (unless there was some wizard nearby kind enough to spam hundreds of dig spells), so the scale is going to be much more modest compared to what's possible with modern construction equipment.