I'm looking for a TV pseudo documentary, from around 200x-201x. I watched it on cable, possibly Discovery Channel. The title maybe similar to "water world" (the movie, I know)
- A giant ice comet crashed with our Moon or passed Earth's Roche limit, form a ring system around Earth.
- These ice meteorites periodically come down, rise the sea level. And whenever a bigger piece falls down, a huge Tsunami formed, wake havoc around the world.
- As the result, governments around the world start various plans to combat this situation.
- Micronesia islands was gone first, created a refugee crisis.
- The EU's plan is build a very high wall around their cities. But one failed catastrophically (a Spain's city I think), as the wall cannot be built high enough, created a huge number of death.
- The US have 2 plan, one is moving higher inland (there could be a scene shows Hollywood Hills with a lot of refugees tent?). Another is build floating cities. Those city is not one big structure, but a collection of smaller modules.
- There is a talk about the floating city's vulnerable to Tsunami, feature [FLIP][1] 

I watched only the first episode, so I can only remember this much.
I tried to googled it with "floating city documentary", "ice comet strike", "flooded earth" to no aval.

  [1]: https://en.wikipedia.org/wiki/RP_FLIP