I wish you luck. Sand, at 2:1 will slough and slide to the bottom of the pond. Sand (at least in my experience} will never seal on it's own. I don't know if you can keep sand at 2:1 slope in place TO seal it....
How many acres of watershed do you have feeding the pond?
Water coming into the pond through the dirt will = water leaving the pond through the dirt when the water pressure inside the pond is greater than outside the pond.
Thanks. Yeah I do think some sand will slogh/slide in a couple spots but not all. I'm going to monitor over the next couple months and see how it goes and how/if it fills. I am confident we have a good bottom layer below the pond at least. Its unfortunate we couldn't have gotten down that deep with the hoe to throw some up on the sides.
It's only 1-2 acres going into the pond for watershed so I'll have to rely on big rains to fill it.
As a contingency if we're having no luck by next year a neighbour who has a clay soil wants to build a pond. I'll plan to rework the slopes and haul in that clay if needed along with getting a slope to the bottom to maybe pull up some of that blue clay to line it.
I'm also tempted to fill in the pond a bit at the bottom as it's quite deep in the one spot. If we can't get to that bottom clay I might just fill it in and that way we can trim out the slopes easier.
The berm turned out nicely though - it is now offering us some privacy so we're still glad we dug the hole that deep.
