How do I know if my pond liner has a leak?

How do I know if my pond liner has a leak?

A pond liner is designed to hold water for twenty years and longer. The most common reasons for water loss are rodent damage, invasive plant roots, low waterfall edging, or an improper filter seal.

Here’s a step-by-step guide to identifying the source of a leaky pond liner.

1. Holes due to rodent damage. Several native animals to Memphis and west TN can cause holes in the liner. These include chipmunks, voles, muskrats, and mice. Animals that commonly burrow underground often form tunnels near the edge of ponds. DIY ponds with stacked field stone are a prime habitat for animals like chipmunks to make holes in the liner. We build our ponds using boulders backfilled against the liner with medium gravel to discourage animals from accessing and chewing the liner.
2. Invasive plant roots. Trees like birch, willows, and elm have shallower roots and will naturally grow towards moist, damp soil. Often this can lead to roots displacing stone, underlayment, and liner causing the water level to lower and leak behind. Also, plant roots can push the liner away from a BioFalls or skimmer causing water loss and damage to pumps and other equipment. Bamboo and River Birch have earned a reputation for puncturing even fabric-protected EPDM rubber liner.
3. Low edges. Soil can move and settle over time causing the edges of the liner to fall. This is most often found in waterfalls and streams. They can also be dislodged by animals, children, or landscapers moving around the pond. Look for moisture outside the liner or a “bubbled” liner caused by hydrostatic pressure under the pond. These are clear signs of a leak. Elevate the faulty edges or use professional waterfall foam to direct the water in the right direction.
4. Check the sealing at the skimmer and BioFalls. When installed correctly, the liner should be properly sealed and connected at both the skimmer and BioFalls. This includes a commercial grade sealant, stainless or brass screws, and waterfall foam. Over time, these seals can breakdown, causing the liner to become detached. A quick way of testing this is to turn the pump off. If the water level continues to go down, you know the leak is the pond and not the waterfall. If the leak stops, there’s a good chance the BioFalls needs to be resealed. You can also look for fine roots growing in the seal between the filter’s face and the liner.

Benefits of a Professional Leak Diagnosis

• Complete inspection reports are documented to ensure the professionals find every leak
• Clear resolutions are presented with accurate pricing
• They have the right tools to fix it
• Memphis Water Gardens provides a lifetime warranty on workmanship

Common Mistakes

• Assuming there’s only one leak
• Not having the right tools (like liner patches or sealant) to fix the leak
• Not knowing the right sequence for troubleshooting
• Lacking the technical expertise for plumbing corrections if the leak isn’t from your liner

FAQ’s

1. How long should my pond liner last? Aquascape’s 45 MIL EPDM rubber liner was originally a roofing material and rated to remain waterproof for 20 years while exposed to direct sun and heat. Once properly installed underwater, protected by fabric, and covered with stone and gravel your pond liner should last for many decades to come.
2. What is the most common reason for a leaky pond? In our experience, the most common reasons for a leaky pond are rodent damage and low edges.
3. How do I quickly find the source of a leak? Turn the waterfall off! Mark the water level on a rock and see if it drops over the next few hours. This can narrow your search quickly and isolate the problem to the pond or waterfalls.

Final Thoughts

Pond leaks are very frustrating, especially if you have fish. For many pond owners, it can be overwhelming to find the source of a leaky liner. Get it done right the first time by bringing in a professional team!