I too made a gradual slope at one end of my pond. I didn't like it. It was too slippery and wouldn't even allow for plants. They kept sliding off. I re-dug that area (as much as my remaining liner would allow) and it's now a lot less of a slope but still I'm not happy with it. If finances allowed, I would pull the liner, re-dig so it was all one depth and drop in a new liner. Bottom line.....no more slopes for me.