If your pool looks off (where one side of the waterline is higher or lower than the other) you’re probably dealing with more than a visual issue. A consistent pool water level helps with filtration, circulation, and chemical balance. It also tells you the structure underneath is stable.
What’s Causing Your Uneven Pool Water Level?
When the waterline isn’t straight, the pool foundation may be shifting. This can lead to cracks, leaks, and expensive damage if not caught early. Here’s how to tell if your unlevel pool is a sign of foundation problems, and what to do next.
Your Pool Foundation May Be Moving
Soil movement is one of the most common causes of an uneven pool water level. Heavy rain, long droughts, nearby construction, or improper backfill can all affect the ground under your pool. As the soil shifts, part of the foundation may sink or settle, leaving one side lower than the other.
If the pool shell drops on one side, the waterline tilts to match. That’s your first clue something below the surface is off. Waiting too long can lead to full structural damage, both in the pool and in nearby concrete or decking.
Cracks and Leaks Follow Shifting
An unlevel pool often leads to cracks in the shell. These cracks form when one area is under more stress than the rest. If water begins leaking through these cracks, you may notice the waterline dropping faster in that section.
Over time, uneven settling and cracking create a clear lean in the pool water level. This can also damage your skimmer function, making it harder to keep the pool clean.
Soil Erosion Creates Empty Space
Soil erosion under the pool is another cause of waterline tilt. When soil washes away, it leaves gaps under the foundation. This creates unsupported areas that can sink under the weight of the water.
Soil erosion can result from poor drainage, broken plumbing, or heavy rain over time. These voids need to be filled to restore support. We do this with foam injection, which fills the space and reestablishes even support beneath the structure.
Learn more about pool foundation repair.
Signs Your Pool is Becoming Unlevel
Noticing issues before the waterline tilts can help you avoid major repairs. Here are some early warning signs:
- Cracks in the pool shell, decking, or tile
- One skimmer pulling water, the other not
- Waterline wear marks higher on one side
- Uneven water movement or surface ripples
- Settling or low spots around the pool edge
If you’re seeing one or more of these, your pool may already be shifting.
What Happens if You Don’t Fix it
Ignoring an uneven pool water level can lead to bigger (and more expensive) issues. As the structure shifts, problems tend to spread:
- Shell cracks grow wider
- Leaks waste water and erode soil further
- Decks or patios begin to tilt or crack
- Pool equipment works harder and less efficiently
- Repair costs increase the longer you wait
Fixing the foundation early with concrete foam lifting protects your pool and your property.
FAQs: Uneven Pools and Foundation Movement
How much tilt is too much?
Even half an inch of tilt can cause skimming and flow problems. If it looks off, it’s worth checking.
Can this be fixed without draining the pool?
Yes. Foam injection can be done with water still in the pool, depending on the condition and location of the issue.
Is polyurethane foam safe for pools?
Yes. It’s waterproof, inert once cured, and used in municipal and commercial pool repairs.
What if the pool was built uneven from the start?
We can still stabilize the soil beneath it to prevent further sinking or cracking.
Will the problem come back?
Not if the soil is properly stabilized. Our concrete leveling foam method addresses both the voids and weak subgrade.
Poor Installation Can Cause Long-Term Problems
If the pool wasn’t installed on properly compacted or graded soil, it might have been unlevel from day one. This doesn’t always show up right away. Over time, small shifts can create a clearly uneven pool.
Sometimes regrading or stabilizing the soil can fix it. In more extreme cases, full reinstallation may be needed, but most pools can be corrected without removing them.
How Leveled Concrete Foundation Repair Fixes an Uneven Pool
We specialize in correcting unlevel pools using advanced soil stabilization methods. Our expanding polyurethane foam LEVELift is injected under the pool to lift and re-support the structure. It fills gaps caused by soil erosion, compacts weak subgrades, and brings the waterline back to where it should be.
This process is clean, fast, and long-lasting. There’s no digging or mess. Your skimmers work like they should, your pool looks better, and the structure is stable again.
If your pool water level looks off, don’t wait. Reach out to Leveled Concrete. We’ll assess the foundation and give you a clear path to a safe, stable, and even pool.