Ok so my customer lives in a residential neighborhood, has a fenced in backyard. Only problem is that the backyard and its fence borders a drainage creek so his property is progressively being eroded by the elements and the area under his fence has been washed away now leaving about a one foot gap under the fence. What kind of products could be used to retain the rest of his dirt and prevent it from being washed away. I know there are silt fences and such, I'm looking for something more permanent. Thought about the bags of concrete that get stacked to make a makeshift retaining wall? Noone see's the area so beauty is not a concern.