There are 4 main options for securing your pond liner.
The simplest method for securing your pond liner is an anchor trench. This runs around the outside of your pond, approximately 500mm from the edge, and should be dug to about 300mm deep by 300mm wide. The liner should lap into the trench, be covered by a layer of matting, then the soil replaced over the liner. Grass can then be laid up to the edge of the pond.
To make the edge of the pond more aesthetically pleasing, you can use a combination of an anchor trench as described above with a small shelf running around the outside of the pond onto which rocks or decorative features can be placed. Once the liner is in place, add a layer of matting on top prior to adding any rocks so the top side of the liner is protected.
Where you want a more formal edge to the pond, large stones or paving slabs can be laid over the liner (with a layer of matting in between) to secure it in place, as long as they are heavy enough to stop the liner slipping. You must ensure that the liner finishes above the level of the waterline as water will penetrate between the slabs below this level and if there is no liner, it will soak away lowering the level of your pond.
You may want your pond to have one or more vertical sides if you want it to butt up against a building or have walls. You can do this using a termination bar and water block sealant (see our pond liner accessories for the parts). For further information on how this is done, see Vertical fixing of pond liner.
Next… How to Install your Pond Liner