This is going to be a bug out room, its going to be a multi purpose place, first a practice foundation for securing the water well house, but then mostly a root cellar. Yet it could be used for future coming storms, or to hide from future flying foes. 

So a place to bug out when you need to, or store a years worth of carrots, potatoes, garlic, onions, ginger, anything needing long term cool storage, so as to not have to pack the fridge, or during times of harvest when the need is greater, and stretching out items until they can be replenished. The soil removed from the room will be used to create a raised bed for carrots, lettice, anything being close in soil PH, small, and possibly going year round.