see my pond is on land with a pretty good downward slope so its a bit tricky. The way my bigger one is, when your standing one the top of the back wall its gotta be 25-30ft down. You could sled down it pretty fast in the winter! that being said, even the small pond is gonna have a big back wall so im trying to figure out the best way to try and keep it level as I dig. I got rid of all the topsoil, now im gonna rent a small excavator to dig it down 10ft.