Leaks are among the most misunderstood and misdiagnosed problems anyone can have in their pond. Understanding the basic principles of leak detection and repair will save you time, money, and headaches when solving your water garden customers problems.

First, let's have a look at what evaporation is and what it isn't. Evaporation is caused by water turning into a vapor and escaping from the pond. The amount of water loss will vary according to the region of the country and the time of year.Ponds that are located in areas of the country with moderate temperatures and high humidity can expect to see 1 to 1 ½ inches of water loss per week during the spring and summer. Most of this evaporation should be replaced naturally by rain. However, if you live in an area with high temperatures and low humidity, it's possible to see 3 inches or more of evaporation in a week.

The quantity and size of your waterfall(s) will also affect the amount of water that is lost. Regardless of the climate, a 4'x 6'pond with a 20-foot stream and 5 feet of cascading waterfalls may lose as much as 2 inches or more every day! Why? Splashing and moving water has greater exposure to additional evaporation than does the still water in the pond. If that same pond was 16' x 21' pond, you'd probably never even notice the additional evaporation because it's a larger pond. 

Evaporation is not filling the pond up all the way one evening, and waking up the next morning to find the water six inches lower. That's a leak! If your pond is experiencing a loss of water at a more rapid rate, you either have a leak, or the frogs are drinking the water. Seriously, let's figure that it's a leak. What do you do then?  

 

Low Edges 

Look for any low edges. Settling at the pond's edge is the most common cause of a leak, especially in a new pond. 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.  

Your first line of defense is to carefully inspect the edges of not only the stream and waterfall, but also the perimeter of the pond. As the dirt around the stream or waterfall settles, it can create low spots that may cause water to escape over the edge of the liner. Keep your eyes peeled for wet mulch or gravel, or muddy areas around the perimeter of the pond. If you find a spot that's leaking, all you have to do is lift the liner up and push some soil under it in order to raise the edge. Bingo - leak fixed!  

Another possibility is that water is splashing out of the stream. To fix a "splash leak," all you have to do is adjust a few of the rocks under and around the waterfall. This will contain or redirect the splash and it will stop the splash leak. Once again, you've solved the problem the easy and cost-effective way ... using common sense.  

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. 

Obstructions in the Stream and Waterfalls 

In addition to checking for low edges, you should also check the stream and waterfall. Rocks and excessive plant or algae growth in the stream or biological filter can restrict the flow of water and divert it over the edge of the liner. Plants and algae should be maintained by trimming them back in order to let the water pass freely. All in all, these leaks are extremely easy to fix.  

Still Leaking? 

You've spent 15 minutes or so following the suggestions listed above and you still can't find the leak in your  pond. What do you do next? It's time for a little more work, and some drastic measures.  We call it the 24 hour test. You'll have to shut the pump off for a day. By doing this, you'll be able to determine the approximate location of the leak.

• Make sure the pond is filled to the appropriate level.
• Unplug the pump.
• Let the pond sit for 24 hours.
• If the water level drops, then you know the leak is in the pond.

When the Water Drops

•  To find out where the leak is occurring, allow the water level to continue to drop. The level where the water stops dropping is the level where the leak is located.
Concentrate your search around the perimeter of the pond at the level that the water has stopped dropping.

Now the fun begins! In order to reveal the exact location of the leak, you'll need to:

• Remove any rocks around the entire perimeter at the level where the water stopped. You can then carefully check for some sort of puncture, or hole in the liner.
• When you find the hole, you simply patch it with a liner patch kit.
• Now you can replace the rocks, and then fill the pond back to the top.

Steady and Level 

 If the water level remains the same, then it is safe to assume that that the leak is not in the pond. Now you'll need to check the pipe, the plumbing fittings, and the pump connections for leaks.  

Another possible culprit is the faceplate of the skimmer. If the water level stopped dropping above the bottom of the faceplate you should investigate the skimmer. It may not have sealed correctly. 

If the Leak Is in the Skimmer

• Investigate the skimmer faceplate without disassembling it.
• Simply move a few rocks around the front of the skimmer and slide your hand behind the liner, feeling for wet soil around the opening of the skimmer. If the soil is saturated, then the faceplate may not have been installed properly and might be the source of the leak.
• Remove the faceplate, clean all of the old silicone off the liner, and refer back to the instruction manual on proper procedures for sealing the skimmer faceplate to the skimmer. Hopefully, you've solved the leak.

It's not fun when your pond is losing water. It can be a time-consuming and frustrating process to locate the leak. Hopefully with these steps and tips, you can help you quickly locate the source of the leak and  get right back to enjoying your water garden.