We just wrapped up a pool leak detection in McKinney, Texas, and this one is a good reminder that a pool losing water doesn’t always mean a broken pipe. After testing every fitting, seal and line on the pool and spa, the plumbing came back clean. The water loss turned out to be coming from somewhere most homeowners would never think to look: the waterfall.
Here’s exactly how we worked through it.
Step 1: Fluorescent Dye Testing Every Fitting
We start every pool leak detection in the water. With a mask and snorkel on, we work our way around the pool and spa, releasing fluorescent dye right at each fitting. If there’s a leak, the dye gets pulled toward it and shows us where the water is escaping.
On this pool, we dye tested:
- Every return jet in the pool
- The main drain at the bottom of the pool
- The skimmers, including the skimmer throats and the skimmer basket area
- The spa jets and spa drain
- All of the pool and spa lights
- The automatic pool cleaner connection
- Every other fitting with a seal or penetration through the shell
The dye didn’t move toward a single fitting. No leaks showed up in the shell, the lights or any of the fittings.
Step 2: Pressure Testing the Plumbing Lines
A clean dye test tells us the visible fittings are sound, but it doesn’t tell us what’s happening in the pipes buried under the deck. So the next step was pressure testing. We plug each line at the pool, pressurize it, and watch the gauge. A line that holds pressure is tight. A line that drops pressure has a leak somewhere along its run.
We tested each system separately and held every one for 10 minutes:
- Skimmer lines: held for 10 minutes
- Pool return (jet) lines: held for 10 minutes
- Main drain lines: held for 10 minutes
- Spa jets and spa drain lines: held for 10 minutes
Every line held. No pressure loss anywhere in the pool or spa plumbing.
What We Found: The Waterfall Was Sending Water Out of the Pool
With the plumbing and shell ruled out, we looked at how water moves around the pool when everything is running. That’s where we found the problem.
There’s a waterfall feature on the side of the pool. Instead of all of that water falling back into the pool, some of it was running down the tile and into the overflow. The overflow has a slight slope to it, so that water was being carried away from the pool instead of returning to it. It wasn’t a leak in the traditional sense, but it was steadily taking water out of the pool every time the waterfall ran.
Adding Up the Water Loss
Based on what we saw, we estimate the waterfall was costing this pool about 1/2 inch of water per day.
On top of that, North Texas pools commonly lose 1/4 to 1/2 inch per day to evaporation, especially in warm, sunny, breezy weather with water features running.
Put those together and the pool could easily drop 3/4 inch to a full inch a day. That’s more than enough to make any homeowner think they have a broken pipe, when in reality the plumbing is in good shape.
Why a “No Leak” Result Is Still Good News
Nobody wants to pay for a leak detection and hear “we didn’t find a leak.” But for this homeowner, that’s the best possible outcome. It means there’s no broken pipe under the deck, no failing light niche and no cracked skimmer. Nothing needs to be dug up. Instead of an expensive plumbing repair, the issue comes down to how the waterfall is sheeting water and where that water ends up.
Just as important, they now have documented proof that every line held pressure. If water loss continues after the waterfall issue is addressed, we know exactly what has already been ruled out.
Pool Owner Takeaways
- Evaporation is real. Losing 1/4 inch a day in a Texas summer can be completely normal.
- Water features change the math. Waterfalls, spillways and fire-and-water bowls increase evaporation and splash-out, and they can send water where it doesn’t belong.
- Watch where the water goes. If you see wet tile, decking or overflow areas around a water feature while it’s running, that water may not be coming back.
- Test before you dig. A full dye test and pressure test of every line tells you for certain whether you have a plumbing leak before anyone starts breaking concrete.
Is Your Pool Losing Water in McKinney or North Dallas?
Lone Star Leak Locators is a local, family-owned leak detection company serving McKinney, Allen, Plano, Frisco, Richardson, Garland, Dallas and the rest of North Dallas. We dye test every fitting and pressure test every line, so you get a clear answer, whether that’s a pinpointed leak or proof that your plumbing is sound.
Call or text 972-333-5448 to schedule your pool leak detection, or learn more about our pool leak detection and pressure testing.
Steven Shipler, TX Master Plumber / RMP License #45825