Once your civilization has sufficient technology, Will you be able to build things like water reservoirs, canals, flatten hill areas, mountains tunnels and do land reclamation?

I really hope they add this to the game, canals and tunnels would make the game so much more fun. Maybe it would also be fun if you would be able to destroy these building. 

For example you would be able to blow up a tunnel or bridge when war breaks out, sealing off you county.

For a civilization like the Dutch, there special district could be a polder and be build on sea and lake tiles.

I would love to see this as well. Being able to slowly change the environment, maybe even unintentionally (over-exploiting resources? Dams getting damaged, resulting in temporarily flooded districts?). Where there is such a large period of history being covered, it would make sense. We may not see tectonic shifts or the like, but still... rivers growing, or drying out, etc. would add an extra level of challenge to growing out your cities.