Free Dirt?

[Austin Davis]

Happy Saturday,

Asking for advice for my personal home this time and not my rentals, but thought my BP friends might have some advice to help me with my issue.  

As you can see in the picture below, my back yard has a small high part and then drops down into a low part with a lot of trees.  The bottom part backs right up to a ditch that the city diverts street rainwater into when it rains, and when it rains hard, this part of my yard will flood, which makes my yard pretty boggy and unusable for several weeks after.  

A solution I have been thinking about is cutting down some of these trees in the lower part, getting A LOT of dirt and extending this back part of my yard back to give us more usable yard.

My question:  What would be the best way to get A LOT of dirt for free?  

I was thinking of trying to develop a relationship with a builder that would just dump dirt in my yard after digging a basement.  Not sure what is done with dirt after new basements are dug, but does this seem like a decent idea?  Any other ideas or advice?