By Dave Kelly
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 in your water gardening adventures … I guarantee it!
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 your 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 your 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 your frogs are drinking the water. Seriously, let's figure that it's a leak. What do you do then?
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 your 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 your 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 your stream. To fix a "splash leak," all you have to do is adjust a few of the rocks under and around your 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.
In addition to checking for low edges, you should also check your stream and waterfall. Rocks and excessive plant or algae growth in the stream or BIOFALLS® 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.
You've spent 15 minutes or so following the suggestions listed above and you still can't find the leak. What do you do next? It's time for a little more work, and some drastic measures. You'll have to shut your pump off for a day. By doing this, you'll be able to determine the approximate location of the leak.
Now the fun begins! At this point, you may want to consider calling in a pond professional, but in order to reveal the exact location of the leak, you'll need to:
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 your skimmer, if you have one. 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
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 quickly locate the source of the leak and get right back to enjoying your water garden.