If you are scrolling in one direction only and you never have to go backwards, that makes it easier to do because now you only have to be concerned with drawing what is visible. You could most probably just draw your current normal non-destroyed environment as like a simple tilemap scroller, and then draw destruction on top of it, in realtime, each frame. Since you probably will be scrolling the destruction out of view sooner or later, you shouldn't have to worry much about it slowing down due to too much destruction objects onscreen.