Overflow Dam
This is the game-changing map alteration that’s been rumored for months. After Infinity Ward suggested that it’s planning to feature Fortnite style map events, the Dam started creaking, and the main menu showed it overflowing. This ending of the Northern landmark is something some players expect to happen.
The chatter involving Captain Price in the Season 4 teaser trailer also points towards chemical weapons being used, which could be in reference to the mysterious stuff inside bunker 11.
Overflowing or simply destroying the Dam could affect more than just that small section too. The towns slightly south, the Airport, and even Stadium could become underwater locations, changing where players can go.
Obviously this would all require the Dam to defrost first, which could also affect the build-up of the snowy north. It would also dramatically change the layout of Dam itself, which can be one of the most frustrating sections of Verdansk in its current state.
However, since the land to the East as you get towards Military Base is higher than the Dam itself, Infinity Ward wouldn’t be able to just level it. You’ll still need to be able to reach the top of it, no matter what is up there.