Just a note on beach erosion. It is generally thought to be dependent on the sand grain size and the slope. You can find that a 25:1 slope is generally felt to be good for ocean front beaches subject to large waves but 10:1 or 15:1 should be sufficient for ponds and such. The article at this link,
https://www.researchgate.net/public...ntology_of_Estuaries_and_Coasts/download contains a nice figure (13) showing slope, grain size relationship as a function of wave exposure. Some authors have also noted that a 10:1 slope might be observed underwater away from the wave area.
I took the conservative approach and used 15:1, which makes it good for water shy dogs and little tykes, and for getting in and out of canoes. At the bottom I put a 15ft wide flat region before a drop off. We will see how that holds up but the flat region limits erosion from above. We have only had water on the beach since November but see no signs of erosion whatsoever, yet.
