I have a customer that lives on a local resevoir. She has been losing her back yard due to erosion from the resevoir. She has asked me about putting in a retaining wall that will stop the erosion. I have seen the use of rip rap on the banks of alot of places and this seems to work pretty good. My question is if I install a block retaining wall up now since the water is down because of drought will it hold up to the water once it rises to normal level. What is a good block system to use for this installation? I thought about using a bigger block with plenty of gravel behind the wall and plenty of drainage to drain the water from behind the wall. Will the water wash away the base material if I use crusher run and compact down?