Pond leak detection: find the water loss before you replace the liner
Most 'liner leaks' are actually a low edge, a splash-out at the falls, a bad skimmer seal or a plumbing joint. We isolate the cause methodically so you only pay to fix what's leaking.



How we find leaks
- Evaporation baseline: rule out normal summer loss
- Pump-off test: level drop with the pump off isolates the pond from the plumbing and falls
- Isolation of stream, waterfall and skimmer sections
- Pressure test on suction and return lines
- Dye and acoustic testing on liners and concrete shells
- Written findings with a repair scope and cost
Leak repair
Edge and liner adjustments, EPDM patching, seam repair, bulkhead and fitting replacement, PVC line repair or reroute, concrete crack injection and full reseal where the shell has failed. Commercial water features get a leak-rate report for the property record.
Signs you need leak detection help
- The pond or fountain loses more than two inches a week
- The level drops overnight with the pump off
- The auto-fill runs constantly or the water bill jumped
- Soil next to the stream or falls is always wet
- The feature has been 'resealed' before and still leaks
What drives the cost
Leak detection is a flat diagnostic fee that includes the pump-off test, isolation and a written findings report. Repairs are quoted separately and range from a liner-edge adjustment to a plumbing reroute or a full polyurea reseal.
What this service covers
Leak detection & repair sits under the wider heading of water feature repair. Clients tend to call it pond leak repair or water feature leak detection; whatever the name, the work breaks down into a few distinct jobs:
Pond liner leak detection
Pump-off level testing and dye tracing to find punctures, seam failures and low edges.
Waterfall and stream leak isolation
Sections isolated one at a time to find splash-out, wicking and liner-edge loss.
Fountain basin leak testing
Basin, plumbing and auto-fill tested separately so the fix targets the real source.
Plumbing pressure testing
Suction and return lines pressure-tested to locate underground breaks.
Concrete shell and crack leaks
Acoustic and dye testing on concrete ponds and fountains, with injection or membrane repair.
Lake and large feature leak assessment
Flow metering, liner inspection and outfall checks with a leak-rate report.
Terms you'll hear from our technicians on this work: evaporation baseline, pump-off test, isolation test, pressure test, dye test, acoustic detection, liner edge, skimmer seal, auto-fill valve, leak-rate report.
Where we offer it
Routed service through Orange County, Los Angeles, San Diego County, the Inland Empire and the Coachella Valley, with construction and commercial crews traveling to Arizona.
Leak Detection & Repair across Southern California and Arizona
Orange County home base, routed crews from Los Angeles to San Diego and the desert. One call, one crew, written findings.
Before and after: leak detection calls
Customer story
A liner leak found the right way, in Long Beach
“They came back about three different times to make sure the leak was in the liner, without just saying, oh, we need to pull the liner out. It could have been a leak in the pipe. It's so clear, and you can hear the waterfall. I would recommend you guys to anyone. Fantastic job.”
Homeowner, Long Beach, CA
A Long Beach homeowner came home to an empty pond. Koi Pros came back three times to confirm the leak was in the liner and not the plumbing before recommending a new liner, then rebuilt the pond with the waterfall he can hear from the house.
Watch: a waterfall and pond repair and reseal in Orange County
A leaking community stream and waterfall, start to finish: drain and vacuum, grind and patch the cracks, spray the sealer, refill, and the waterfall running again. About two minutes. This is the same crew that handles leak detection.
Guides on leak detection
Maintenance · 4 min
What to Do When Your Pond Pump Not Working?
Learn how to fix common pond pump problems, including equipment that won't prime, leaks, and clogged filters. Keep...
Maintenance · 8 min
Signs Your Pond Needs Professional Cleaning Services
Learn the key signs your pond needs professional cleaning services, from murky water to algae growth. Keep koi...
Construction · 9 min
Koi Pond Installation: What Every Homeowner Should Know
How to plan, design, and maintain a koi pond. Koi pond installation steps, costs, and why hiring a professional...
Questions about leak detection
How much water loss is normal?
Roughly 1–2 inches a week in summer from evaporation, more with a waterfall or in desert climates. Losing that much overnight or with the pump off is a leak.
Do you find leaks in commercial fountains and lakes?
Yes. Large features are tested in sections and with flow metering. For lakes we assess liner, shoreline and outfall structures.
