Determining the cause of water under a liner requires careful observation of the conditions surrounding your pond or water feature. Here are the main considerations:
Water Loss in the Pond
- If water is accumulating under the liner and you are losing water from the pond, it is likely that the water under the liner is caused by a leak in the pond or water feature.
- The leak allows pond water to escape and seep beneath the liner.
No Water Loss in the Pond
- If your pond is not losing water and you still notice water under the liner, the likely cause is groundwater.
- This is especially common after heavy rainfall, during the spring thaw, or in areas with a naturally high water table.
Signs During Maintenance
- If you are performing a pond cleanout and, after draining the pond, you notice the liner bubbling or lifting, this is usually caused by groundwater pressure pushing up against the liner.
Factors Contributing to Groundwater Presence
- Recent heavy rains can saturate the ground, increasing hydrostatic pressure beneath the liner.
- Seasonal conditions, such as melting snow or ice in spring, often cause groundwater levels to rise temporarily.
By examining whether the pond is losing water, recent weather conditions, and signs during maintenance, you can identify whether the issue is due to a leak in the feature or external groundwater.