Leaking pond: How to find pond leaks and fix the problem

If you’re a pond owner there is nothing worse than seeing your ponds water level drop, the first thing you suspect is a leaking pond, but often it isn’t the case, so today we will go through the most common causes of water loss.

Most water leaks in ponds are usually found outside the pond in the hardware that runs your pumps, filters and waterfalls rather than holes in your actual pond.

Water leak in your pond?

A simple way to check if it’s the pond or hardware thats causing the problem is to look at the waterline around your pond, if the water drops and then stops dropping while the pump, filters and waterfall are still running that’s a sign of a leaking pond.

If the pond water stops dropping the leak will be around the waterline, run your fingers around the waterline rubbing off any algae to see if you can find the leak or leaks, when you find the leak use the appropriate leak repairer/sealer to repair the leak, fill the pond and if it holds water the leak is fixed.

The above scenario works well if the leak is only a few inches or so below the normal level of pond water, but if the water levels keep dropping you could endanger your fish, the problem you then have is, is the leak low down in your pond or even on the bottom of your pond or is it coming from outside the pond.

If you have a big loss of water over a short period of time you need to look at your pump, is it actually sending the water to your filter or waterfall that’s outside of your pond or is the water being lost through other means.

Is your waterfall leaking?

Waterfalls account for the majority of problems when it comes to leaks, so lets start there. First check to see if there is a build up of plants, leaves or algae causing a dam, if there is this could force the water over the edge of the waterfall or liner and not enabling all the water to run back into the pond. Clear away anything that’s blocking the waterfall and see if that solves the problem.

Waterfalls can often leak allowing the water to seep into the ground around the pond and not back into the pond, check the ground around the waterfall to see if its waterlogged and check to see if there are any visible signs of leaks, if it’s a preformed waterfall there might be holes that you can see, if it’s a liner with stones on top the only way to check it is to dissemble the waterfall and check the liner for holes, sometimes it just needs to be repositioned. If there is any damage or holes repair or replace them and keep an eye on the ponds water level to see if that’s solved the problem.

Does your plumbing have a leak?

Your pond pump pumps water from the pond to various features and filters outside the pond, so do a visual check on all your plumbing that you can see, if a leak is found in a hose replace the offending hose with a new one.

Is your filter leaking?

If you have checked all the hoses that run from your pump and found no problems check your filters and the fittings to make sure they are not leaking, if a leak is found it’s usually one of the fittings or a seal rather than the filter itself but filters can overflow so check this and find out why its overflowing then fix the problem.

Is the leak in the pond or not?

There is a way of finding if the leak is in the pond or not. The first thing you do is turn of all the pumps and water features, if you have a bubbler or air stones you can leave these on as they will provide oxygen for your fish while the pumps are shut down. Take a note of the water level so you can compare it latter.

If you have a pond that is heavily stocked with fish you need to be a bit careful, turn everything off in the evening about 8 or 9 o’clock and only leave everything off for 12 hours. The following day at about 8 or 9 o’clock check the water level, if the water level has dropped the leak is within your pond, if the water level has stayed the same the leak is outside of your pond.

We like to do this check as a last resort after a complete visual check of the pond, water features and hardware so we don’t cause the fish any due stress.

The biggest problem with leaks are in the pond, outside of the pond are easy fixes and can be done by shutting down the pond while the fix takes place, sometimes you don’t even need to shut the pond down.

If the leak is in the pond you need to find out where too, this can be simple if its high up but a lot more difficult if the leak is low down. The only way to find out where the leak is in a pond is to let the water level drop until it stops.

This can be very stressful for your fish and you need to be constantly checking your pond so the water doesn’t get too low, if you are getting to the stage where the water level is dropping to low for the fish you will have to remove them with any plants you have and put them in a holding tank.

Where the water stops is usually where the leak will be found, repair the leak using one of the leak repair kits you can buy and refill the pond. There is a possibility you could refill the pond and find it still leaks, this is usually because there was another leak further up that didn’t show up or whilst patching the original leak you accidentally caused another one. Once you have filled your pond keep an eye on the water level, if it doesn’t drop dramatically the leak is fixed.

How to fix a leak in your garden pond.

Once you have found your leak its time to make repairs. As long as the leak is repairable there is no reason why after repairing the leak your pond will hold water for the foreseeable future.

Concrete pond

If you have a concrete pond you can use a product like just fix it.

This two part putty can repair cracks and holes in concrete even under water.

You can buy it from bradshawsdirect.co.uk

Flexible Liner pond

For a pond with a liner you can get a liner repair kit.

They work in the same way as a tyre puncture repair kit.

Dry the area to be repaired, apply the super strong adhesive and stick the patch to the liner.

You can buy this kit from bradshawsdirect.co.uk

If the damage to your pond is too big to be fixed you might have to replace the complete liner or re-render your concrete pond.

Evaporation and spillage.

Don’t be confused with water loss due to evaporation and spillage, we have another article that covers this topic that you can read here.