Then what question are you really asking? Alternative forms of travel and transport than boats, or are you asking what life would be like if society was based on a city like Venice?
Canal based cities are a possibility, but there are many other factors that you should be aware of:
City Life:
I visited Venice once. It is a very beautiful city with lots of canals, bridges, etc, but the old town which everyone thinks about is actually only a small area of a couple of square miles. I could not imagine what a large sprawling city like Los Angeles would look like if there were canals instead of streets and rivers instead of freeways.
* Major cities are limited to the coast (tidal?), river banks and man-made aqueducts
* Flooding may be a constant threat (buildings should be made of stone and first floor of buildings should be dry-season use only)
* Buildings may not be very tall either (Venice only has a few buildings taller than 3 or 4 stories and they have a problem with sinking)
* Drought may also be a major disruptor to inland trade and travel
* Locks and dams to keep water from flowing downstream will cause stagnation, foul smells, pests, and disease
* Water-born diseases (without clean drinkable water an illness started upstream might devastate an entire nation)
* Trash may pile up
* People will be starkly divided into haves and havenots
* Gangs and thugs will be a constant problem (lots of hideaways, that even police will have a hard time keeping control)
Resource Gathering
* Vegetable farms would be small plots that are close to navigable water (the issue is not whether the land is fertile, but rather getting the harvested crop to buyers)
* Grains and breads could only be afforded by the middle and upper classes
* Because of supply and demand, farm owners will be one of the richest individuals in society
* Rooftop gardens would be very common (unless town is often affected by storms)
* Fish would be primarily the source of food for the city poor
* Red meat will be extremely scarce as many of our beasts of burden are also our food supply (ox, horse, deer, etc)
* Trappers and hunters may provide a high demand product, but it would be difficult to get the meat to the city while still fresh (more likely only the skins are sent)
* Possible to have rabbit and chicken farms, but feeding them would be expensive (wild chickens and rabbits outside the city might be a good industry for orphans)
Warfare:
* Areas away from any navigable source of water would be considered barbarian and wild
* Those that live outside of the cities would be feared
* War between nations are mostly limited to navy
* Assaults on cities can be controlled by a few well guarded access points
* An overland army march from out of the wilds would catch everyone by surprise (but keeping army fed would be extremely difficult)
Original Answer:
Ants can lift 1000x their own weight.
So build a "sled" that rests on "giant" ants (the size rats). The ants are bred and have the queen installed inside the sled to communicate navigation. 87