When determining if a liner is the best option for you, some considerations should be made:
1. Existing water – Many ponds retain some water; however, we do not recommend lining a pond that contains more than 25% of its fill capacity for any extended period of time. If your pond is more than 25% full and you want to use a liner, you would need to drain the pond before laying the liner or put at least 2' of soil atop the liner.
2. Pond size – Measuring your pond is best accomplished using a flexible tape measure (available at local hardware stores). Stretch the tape measure from waterline to waterline allowing the tape to contour the pond's bottom. In general, we recommend adding an additional 15' to 20' to this number to make up for the liner settling and the anchoring trench. When doing the installation, the anchor trench will hold the additional liner and keep it secure; it is located 5' from the pond's edge.
3. Slope – Steep slopes can put too much stress on a liner and cause premature wear. Both PVC and RPE liners are designed to be used in ponds no steeper than a 3:1. For example, in a pond that has a 3:1 slope, if you drew an imaginary 3' horizontal line from the pond's edge, the pond would be 1' deep at the end of your line.