I had to dig down a little further in to the boulder clay subsoil to get it on a nice steady SW-NE gradient, and the trench you can see has filled with water since Wednesday, which is a good thing, I hope. This was Saturday afternoon, and it's rained a lot since then.
I made a bit of progress with the path, too, couple of flags further. It's a tedious job, frankly, but it gets easier as the end approaches. It feels like the allotment is getting a new backbone.