Leaking pond repair: Tips for locating and patching the leak

A leaky pond is a common pond problem, locating and repairing the leak is the solution to the problem.

How do I detect a leak in the pond?

1. If the water level remains at a lower but the same level, the hole in the wall will sit above the current water level. This is beneficial. Refill the pond by several inches and now look along the pond edge to see if the leak can be found. You do this, for example, with a colored liquid like milk, so you can see where the water flows, so to speak; this will be at the leak. You stick the leak just like an air mattress using a repair kit available in stores.
2. If the hole is in the bottom then the pond will drain equally to completely. Here you will have to wait for the leak to be found. If the pond is almost empty, you can try the same tactic with the milk again in the little bit of water left.
3. Finally, in older ponds, the liner may have worn out and water is slowly seeping out. This is more common in ponds with pond liner made of PVC, because it has a shorter lifespan than rubber liner; about 8 to 10 years versus at least 20 years. In this case, the entire pond will have to be drained and re-lined. See the step-by-step plan for (re)constructing a pond.

How do you fix a pond leak?

1. Lower the water to well below the leak.
2. Clean the area around the leak thoroughly, such as with spirit.
3. Check if a sharp object is the cause of the leak and remove it if necessary.
4. Depending on the type of liner (PVC or EPDM), get a suitable repair kit from a garden or pond center or online. For PVC liner, use PVC glue and a piece of liner; for EPDM, use rubber glue and a piece of rubber liner.
5. After the leak is repaired, you can fill the pond again.

What are causes of a leaking pond?

Causes pond leak: When a pond leaks, the liner is no longer waterproof. This can be due to:

1. A leak in the bottom: the pond drains completely. This leak can occur because the pond liner has aged. PVC-pond liner lasts 8-10 years on average, while EPDM-pond liner lasts 20 years on average. If this period has passed without replacing the liner, you have a chance of a leak in the pond and the pond draining.
2. A leak in the wall: the water stops sinking as soon as the leak level is reached. Again, this problem can be caused by outdated pond liner, but it can also be due to an animal gnawing a leak in the liner or plant roots puncturing the liner that may have already become somewhat porous.
3. Porous PVC film: sticking does not help, replacement of the film is necessary. PVC sheeting lasts 8-10 years, while rubber sheeting (EPDM) takes at least up to 20 years to become porous.

Expert tip: Placing new pond liner

Choose pond liner that has a long lifespan, if you want to save yourself work then choose rubber sheeting (EPDM). It usually takes EPDM-pond liner a minimum of 20 years to a maximum of 50 years until it becomes porous. How quickly this liner becomes porous depends on the placement of the liner. Do not place the pond and liner in full sun, but rather in an area where there are moments of sun and moments of shade during the day. This prevents the quality of the pond liner from deteriorating rapidly.