A pond is a lovely addition to any garden, but when your pond develops a leak, it can be a frustrating experience. Pond leaks can develop for a number of reasons, such as a rock, branch or animal tearing the liner or the ground settling underneath the pond. If your pond is made of plastic or contains a plastic liner, you can easily fix the hole with items found around your home and in your local home improvement store.
Turn off the pump and let the water leak out of the pond until the water level stops falling. The water will leak out until the water level is just below the hole. Set up a temporary place to move any fish or plants in case the water level falls low enough to harm them.
Look carefully along the waterline of the pond until you find the hole. If you are having a hard time finding the hole, add about one quarter inch of water and use an eye dropper to dribble a few drops of milk down the side of the pond. Watch carefully to see how the milk moves when it enters the water. Continue dripping milk around the edges of the pond until you find the leak.
Drain the pond until the water level is at least four inches below the leak. You can either wait until the water evaporates naturally or remove the water with a pump or bucket. If the leak is in the bottom, drain the pond completely.
Scrub around the leak with a scouring pad to clean the surface. Do not use soap if there are still fish and plants in the pond. Let the area around the leak dry completely. If the surface of the pond is very smooth, you may want to roughen it up with steel wool so that the adhesive sticks better.
Cut a piece of pond patching material about two inches larger than the leak on all sides. Apply the adhesive, following the directions on the package, and place the patch over the leak. Smooth out the patch, evening out any lumps in the adhesive. Apply a small amount of adhesive along the edges of the patch to seal them. Allow the adhesive to dry completely.
Refill the pond and watch the water level closely to make sure the leak has been fixed. If the hole in your pond has been successfully patched, replace your fish, plants and equipment.