How to Find a Leak in Your Pond

Could you have a pond leak, thirsty fish, or evaporation?

A pond leak is only one of many reasons that your pond might lose water. If it is a leak, though, finding the exact location is like finding a needle in a pile of haystacks – and you need to figure out which haystack to search first.

Luckily, you can solve many water-loss issues yourself. And if you do have a leak that needs repaired, you can take steps to find the source of the problem before the service team arrives.

At a Glance: What to Do If Your Pond is Leaking

  • Water will evaporate naturally, especially in dry or hot weather. Long shallow streams or tall splashy waterfalls contribute to this evaporation. One inch or more of water loss in a week could be normal for many ponds. 
  • Transpiration is when plants use water.  Yep, trees (and other plants) can drink a lot of water.  Studies have shown river birch can transpire more than 20 gallons in a single day. Wow! 
  • Check your stream and waterfall for debris build-up or excessive plant growth.
  • Check your stream for low liner along the edge, areas where the liner is pushed down.
  • Do the 24-Hour Test: Turn off the pump for 24 hours and see if the water level is still dropping.

What is Evapotranspiration?

Pond owners often assume that any drop in their water level means they have a leak in their pond. The reality is many apparent “leaks” are nothing more than normal evaporation.  Long shallow streams or tall splashy waterfalls contribute to this evaporation. One inch or more of water loss in a week could be normal for many ponds. 

A pond with a large, splashy waterfall will lose more water to evaporation than one with a smaller waterfall. Water features will also lose more water in a hot, dry summer than they will during a rainy spring. The key is to figure out what level of evaporation is normal for your pond. 

Transpiration is when plants use water.  Yep, trees (and other plants) can drink a lot of water.  Studies have shown river birch can transpire more than 20 gallons in a single day. Wow!

TIP: When figuring out how much water your pond is losing, use the skimmer – not the pond rocks – as your point of reference.

The 24-Hour Test

If you feel like you’re losing more water than you should be, try running what we call the 24-Hour Test for pond leaks. Here’s how it works:

  1. Unplug all of the pumps.  (Make sure you have an aerator running to keep water oxygenated for fish).
  2. Fill the pond to the full level and take a picture. If you have a professional-grade skimmer, the full level is right at the edge of the overflow that is built into your skimmer.  
  3. Leave the pond sitting at a full level without the waterfall running for 24 hours.
    Note the water level after the 24 hours. Take a picture.

PRO TIP: When figuring out the full level or how much water your pond is losing, use the skimmer – not the pond rocks – as your point of reference. Water can wick up on the rocks creating a wet line 1/2″ to 1″ above the water creating the mistaken impression that the water level is dropping.

Pictured: Not a leak. The water line on the rock is simply a result of the absorbent stone wicking up moisture.

If your water level goes down when the pump is not running, then we know there is a problem in the pond itself (likely the pond liner or your skimmer weir seal.) We want to let the water keep dropping until it stops. This will tell us the exact water level where the water loss is occurring and help narrow down the search for the problem area.

If the water level does not change and the problem occurs only when the waterfall is running, then the issue is most likely in the stream, waterfall and/or plumbing.

If the Problem is in the Pond …

Keep your pump turned off until the water level is stable (not dropping) for 24 hours.

If the water line stabilizes at a level corresponding with the skimmer weir/faceplate, dig down around the skimmer and check for wet ground behind the liner. If the ground is wet around the skimmer, you might need to reseal the weir/faceplate with new screws and fresh fish-safe silicone. 

If the level drops below this area, the problem is most likely a hole in your liner.  Visit Splash Supply Co. at 1298 Toronita St. in York, PA for the tools and advice you need to fix the problem. If you would prefer to have us do the work, give us a call to schedule pond service. Our professional team will get your pond back on track without any more worries.

If the Problem is in the Stream or Waterfall …

You’re more likely to lose water through your stream or waterfall than you are to lose it from your pond. And the issue often has nothing to do with a tear in your liner. Here are a few reasons you might be losing water from your stream, waterfall, or pipe and plumbing:

  • Evaporation: You’re more likely to lose water through evaporation if you have a large or particularly splashy waterfall.  One inch or more of water loss in a week could be normal for many ponds.
  • Blockage or Debris build-up: The No. 1 cause of apparent stream leaks is debris build-up at the top of a waterfall. Growing plants, dead leaves, sticks and other gunk form a kind of dam until the water rises up and out of your stream. Fixing your water loss issues is often a simple matter of removing the debris.
  • Low edge or pushed-down liner: Walk the length of your stream and look for sections of liner where the top edge seems to sit lower than it should. Your liner might have slipped where somebody stepped on it or heavy rains washed away the surrounding soil.
  • Moving rocks and gravel in your stream and waterfall can change the water level and the way the water flows. We love playing in our streams and waterfalls, and fixing the problem may be as simple as adjusting a few rocks that have shifted out of place.

Testing the Pond Pipe and Plumbing …

We rarely see pipe and plumbing issues in ponds installed using professional-grade materials – but problems do sometimes happen.

The most common damage to pond pipe happens as a result of water freezing in the pipe or plumbing fittings. Other times, tree roots will push against plumbing and cause damage.

Here’s how to test if your pipe or plumbing is the cause of your water loss:

  1. Unplug and disconnect your pumps.
  2. Remove the check valve assembly and insert a plug into the bulkhead fitting in the back of the skimmer. Most of our professional skimmers use a 2-inch threaded bulkhead fitting requiring a 2-inch threaded plug. Be sure to put a little bit of silicone on the threads for a tight seal.
  3. Fill the biofalls (and pipe and plumbing) to the very top.
  4. Wait 24 hours and check the water level in your biofalls.

If the level has not changed in the biofalls after 24 hours, you can rest easy knowing your pipe and plumbing does not have any leaks. 

If the level does drop, you may need professional repair service. Fill out our pond service request form to get in touch with our experts.

If you cannot perform the above test because you do not have a professional skimmer and biofalls, fill out our easy online form to get in touch with our pond service team, and we may be able to guide you.

How Much Does It Cost to Fix a Pond Leak?

We hope you found this advice helpful as you attempt to diagnose and fix your pond’s water loss.

If you need supplies or advice, we hope you’ll visit our retail store and display garden in York, PA. Our team would be happy to help.

If your pond leak is beyond what you can fix on your own,  fill out our easy online form to get in touch with our pond service team.

Please follow the recommendations above before filling out your form. These steps help us more quickly find the cause of the problem – saving you time and money.

Leaks that aren’t the result of one of the issues we’ve already mentioned are often time-consuming to diagnose and repair. In our York, Hanover, Lancaster and Baltimore local service areas, initial leak diagnostic visit starts at $575, with repairs billed separately during a follow-up visit.  Repairs can typically run an additional $800, plus equipment, supplies and materials.

Here’s a look at a typical Leak Repair process:

Initial Leak Diagnostic Service Visit

  • Our team will check the pump, plumbing, filters, pond liner, stream liner and waterfall.
  • The $575 starting price includes one hour of diagnostic service, including driving time.
  • Although we will attempt to diagnose the leak issue during the first service visit, we cannot guarantee we will be able to completely diagnose the leak issue during this initial visit.
  • After the first hour of service, we will prepare a report and let you know what we discovered.
  • It is important that you are available to speak with the service coordinator via text or phone during your diagnostic service. The crew will not proceed with any repairs without approval from the service coordinator.
  • The Initial Leak Diagnostic Service Call is for diagnostic services only. REPAIR SERVICES ARE NOT INCLUDED.

Leak Repair Service Visit

  • For repairs, our daily crew rate is $2,500 plus equipment, supplies and materials. We invoice in 1/3 day increments. The minimum charge for repairs is typically $800 plus equipment, supplies and materials.
  • If an issue is diagnosed and the repair does not require any parts or supplies, we will attempt to make adjustments and repairs as required. Issues that can occasionally be resolved during the initial visit include clearing debris, adjusting low edge liner or minor adjusting of small rocks or gravel.
  • Sometimes water loss stems from other issues that are more difficult to detect. These causes include issues with buried pipe or fittings and holes or tears in liner hidden behind rock and gravel. These situations often take multiple visits to diagnose and additional visits to repair.
  • When your stream is very long or you have multiple waterfalls, we may recommend testing each section one area at a time. This would require installing a temporary pipe and testing each section for 24 hours until we can replicate the problem and narrow down the area where the problem occurs. 
  • Sometimes there may be multiple issues, and we are only able to detect the issues one at a time. In these situations, we may only be able to diagnose and repair one issue during a service visit, with additional issues requiring more visits and continued diagnosis and repair. 
  • If we cannot resolve an issue during the first repair visit, we will prepare an estimate with a plan for additional diagnostics and repairs. Frequently, at this point, your pond leak technician will recommend a complete renovation as the quickest and least expensive option. This guarantees all leak issues will be resolved and backed up by our professional warranty.

Sound like a lot of work, time and money? It can be, but don’t worry; a lot of leaks and water loss are the result of the easy-to-fix issues we discussed above: debris-clogged waterfalls, pushed-down liners or simple evaporation. That’s why it’s so important to go through our DIY diagnosis guide before calling the pros.

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