Enough rubble FFS!

[kalos72]

I just realized that they will have to clear roughly 50 square miles of rubble in order for my PC's to plant crops on Staten Island.

How many things can you build from concrete/brick rubble? A rubble perimeter wall, around everything what 10-12 feet high? Perhaps some really crappy one story buildings( anyone have images to suggest)?

Land fill to make the island bigger? Build a huge ass sea wall to make another port? Dump it out to sea? A wall around the whole friggin island?

Suggestions?