Troubleshooting Pond Leaks

Note: Pond Leaks – “Anytime you are troubleshooting for pond leaks in extreme heat it is mandatory that you provide aeration to your pond when you have your pump shut down for any period of time!”

Step 1: Does Your Pond Actually Have A Leak?

It’s hard to imagine how much water can evaporate from a pond during the dog days of summer.

  1. It’s been our experience here in Southern California that you can typically lose 1” to 1 ½” inches of water each week.
  2. Pond owners in the hot, arid climates of the upper and lower deserts, Victorville and Palm Springs, have reported evaporation levels in excess of 3” a week.

Remember, these are averages. Some ponds may not experience evaporation levels this high, while other ponds with large pumps pushing high volumes of water, and /or ponds designed with multiple waterfalls with a lot of cascades and splashing, may have evaporation rates much greater than these.

Step 2: Look For Low Edges

  1. Here’s a little secret. 99% of all “pond leaks” are not due to a hole in the liner, but rather water making its way over the edges of the pond, stream, or waterfalls, due to an overgrowth of aquatic plants.
  2. Look for any low edges. Settling at your pond’s edge is the most common cause of a pond leaks in a new pond.
  3. Typically, the low edges are found around the stream and waterfall where settling may have occurred after a few rainfalls. These areas are usually built up during the construction of the pond using the soil from the excavation, and are prone to some settling.
  4. Low edge signs
    a. Wet mulch along the edge of the pond or stream
    b. Wet gravel along the edge of the pond or stream
  5. You may need to move back the gravel in certain areas to find the low edge.


How To Fix A Low Edge

Low edges can be built back up by simply backfilling and compacting soil beneath the liner in order to raise the edge of the liner above the water level.

Step 3: Look For Obstructions In The Stream And Waterfalls

Check to make sure nothing is causing the pond leaks by restricting the flow of water down the “waterfall or stream”. Any adjustment of the rocks in the waterfall may have inadvertently caused some of the water to be diverted over the liner.

Water can also make its way over the edge due to excessive aquatic plant or algae growth in the stream or biological waterfall filter. The water simply gets backed up from all of the aquatic plant growth. Plants and algae should be maintained by trimming them back in order to let the water pass freely.

Step 4: Shut Down The Pump

You have spent 15 minutes or so following the suggestions listed above and you still can’t find the leak. Well, we now have to go one step further and try to narrow things down a little more.

  1. Turn off the pump and leave the pond for a period of 12 hours or more (If your pond is heavily stocked with fish, provisions for supplemental oxygen may be necessary).
  2. After 12 hours, look to see if the water level has dropped in the pond.


What Does This Determine?

  1. If the water level has dropped then you know the leak is in your pond.
  2. If the water level remains the same in your pond then it is assumed that the pond leak is in the stream or plumbing.


If The Leak Is In Your Pond

  1. If you are concentrating on looking for the pond leaks, then completely ignore the waterfalls/stream.
  2. When the water level has stopped dropping, then concentrate your search around the perimeter of your pond at the level that the water has stopped dropping.
  3. If the water level stopped below the bottom of the skimmer faceplate you can rule out the skimmer and concentrate elsewhere.
  4. If the water level is above the bottom of the faceplate you should investigate the skimmer. It may not have sealed correctly, but don’t tear apart the skimmer faceplate.


If The Leak Is In The Skimmer

  1. Investigate the skimmer faceplate without disassembling it.
  2. Simply move a few rocks around the front of the skimmer and slide your hand behind the liner. Feel for wet soil around the opening of the skimmer.
  3. If you do determine it is the skimmer, you will need to pull it apart, clean it and re-apply the silicone and set the screws.


If It’s Not The Skimmer

  1. Investigate the liner for small punctures around the perimeter of your pond where the water level has stopped.
  2. Unfortunately, the only effective way to find this type of pond leak is to start moving rocks and gravel and search for the pond leak by hand and eye.
  3. The pond leak, once found, can be easily fixed using EPDM patch tape.


Good Luck and Happy Pondering!!!