Giving it away!?!? Well dang then I'll TAKE IT. Erosion is eating the sides of the ditch to the tune of about 50 feet a year over a quarter mile stretch.
Rip rap like that is expensive Tony -- your son can probably sell it for real.
Old mattress springs with the coverings removed will do wonders for bank erosion. I had a buddy that had a lot of river frontage and I had the mattress company so I used to give him all the old stuff that came in to stack against the bank in the trouble areas. It worked really well.