After a couple of little niggly jobs, like cutting the grass back from my water butt slabs, I got on with digging the pond. I started using the spirit level and got the top edges even enough. The sand layer will straighten out any tiny discrepancies.
In order to know how deep and wide to make the marginal shelf, I bought the first and main plants for the pond: Japanese sweet flag for the far corner; white magus for the front corner and front edge to help hide the liner; a yellow flag iris for the side, most likely to be joined by others in the bank; and a creeping jenny for the bank or shallow water.
The shape of the pond is almost done now. It’s deep enough in the middle, the shelves are the right depth, but I need to make more of a shelf at the front right hand side, so there’s room for a plant. I also need to check that the water level hits correctly from left to right.
I’ll test with a scrap of plastic to see how easily it fits into the shape I’ve made – the narrow deepest point particularly.