Also, our beach area will receive virtually no runoff so I'm not going to place a berm around the beach above water because I dont think material washing onto the exposed beach will be an issue.
Reconsider.
Our project does have some land that is part of the same beach slope, but above the beach. It is not a substantial runoff for the pond, but it does lean down to the top of the beach area. As water always does, it makes it's own path on the way downhill. I regret not making the berm ever-so higher across the top of our beach area because 2 areas of water coming down the slope did wash some smaller amounts of clay/loam soil into the sand zone. Going back, I would have raised the berm by a couple of inches and paid more attention to make sure it is a negative slope all the way across the top to keep southbound water streams from topping the berm.
