Pool Main Drain Leak Repair in Katy, TX – Before & After

If a pool in Katy keeps losing water even with the pump switched off, the main drain line is one of the first places we look. In this Katy project, Orbit Pool Leak Detection traced a steady water loss to a failed main drain fitting buried beneath the pool, repaired it, and verified the fix with pressure testing. A leaking main drain rarely resolves on its own — it keeps washing soil out from under the pool and quietly running up the water bill until the line is properly repaired. Because the main drain sits at the deepest point of the pool and its plumbing runs underground, finding the exact break takes professional pressure testing and a precise, targeted dig — never random excavation. At Orbit, underground pool plumbing is our specialty. We provide expert pool leak detection and main drain repair across Katy and the surrounding west Houston area.

How the Main Drain Works — and Why It Leaks

The main drain pulls water from the very bottom of the pool and feeds it to the filter and pump, making it central to healthy circulation. When the underground line cracks, a fitting fails, or a glued joint separates, water escapes continuously into the soil below — and in Katy, the area’s expansive clay, which swells and shrinks through every wet-and-dry cycle, is one of the most common reasons those buried joints finally give way. Common causes:

Ground movement in Katy’s clay-heavy soil
Cracked PVC fittings
Separated underground pipe joints
Aging plumbing past its lifespan
Poor original installation

How to Tell Your Main Drain Is Leaking

Watch for:

The pool keeps dropping even when the equipment is off — a classic main-drain clue
Air pulling into the circulation system
Weak or uneven water flow
Soft, wet, or sinking ground near the pool
Water bills climbing with no clear reason

A suction-side leak like this almost always gets worse the longer it runs.

What We Did on This Katy Project

Once pressure testing confirmed the leak was on the main drain line, we opened only the ground directly over the failure point, keeping the excavation as small as possible. The repair included:

Targeted excavation over the confirmed leak
Exposing and locating the cracked underground fitting
Cutting out the failed PVC section
Installing new fittings and pipe
Sealing and securing every joint
Re-pressure-testing to confirm zero water loss

The Result

With the main drain line rebuilt, the constant water loss stopped and the pool’s circulation returned to full strength. Every new joint was pressure-tested and verified leak-free, ending the underground soil erosion before it could undermine the pool shell. Like all our work, this repair is backed by our 2-year warranty.

Main Drain Leak Repair in Katy & West Houston

We handle main drain and underground pool plumbing leaks throughout Katy, Fulshear, Cypress, Richmond, Sugar Land, and the surrounding west Houston area. Pool dropping even with the pump off? Call (346) 850-9775 or schedule online — we’ll find it and fix it.