Pool Era field notes · Care and ownership
Is My Pool Leaking or Just Evaporating?
Topping off the pool every few days and wondering if it's leaking? In a Hill Country summer, a lot of that loss is plain evaporation.
A simple bucket test can tell you which one you are dealing with.
Evaporation
Heat and wind pull water out.
Water leaves any open surface faster when it is hot, dry, sunny and windy. The Texas Water Development Board tracks lake evaporation across Texas for water planning, and it defines gross evaporation as the water a lake loses from its surface to the air.[1]
A pool loses water the same way. Expect to add more water in July and August than in winter, even with no leak at all.
The test
The bucket test.
- Fill a bucket with pool water and set it on the first or second step, so it sits in the pool at the same temperature.
- Draw a line at the water inside the bucket, and a second line on the outside of the bucket at the pool's level.
- Run the pump on its normal schedule, and turn off any auto-fill.
- After a day, compare the two drops. A pool that lost more water than the bucket may have a leak.
- Try it again with the pump off. If the loss changes a lot, the leak may be in the plumbing.
Signs
Signs it may be a leak.
- Wet spots, soft ground or new green growth near the pool or the equipment.
- Cracks in the tile line, the shell or the deck.
- Air in the pump basket, or a pump that keeps losing its prime.
- Loose tiles, or gaps where the coping meets the deck.
- A water bill that jumps for no clear reason.
Why it matters
Water costs more in a drought.
During deeper drought stages, the San Antonio Water System adds a surcharge for single-family homes that use more than 20,000 gallons in a month in Stage 3, or more than 12,000 gallons in Stage 4.[2] A slow leak in a dry summer can push a bill over that line.
A leak can also wash soil out from under the deck or the pool. The sooner it is found, the smaller the repair tends to be.
If the bucket test points to a leak, a pro can check the plumbing and the shell. Leak work is scoped in writing after the pool has been seen.
Related
More field notes
Care and ownershipPool Water During Hill Country Drought RulesHow drought stages work, and what they mean for filling and topping off.Read 
Care and ownershipHard Water and White Scale on Pool TileWhy white crust builds up on tile, and how to slow it down safely.Read 
Finishes and renovationSigns It's Time to Replaster Your Pool (and When It Isn't)Rough spots, stains and worn patches: when to replaster and when it is just the water.Read
Sources
Where these facts come from
- Texas Water Development Board: Lake Evaporation and Precipitation
- San Antonio Water System: Drought Restrictions and Watering Rules
Sources checked October 25, 2026. Rules, fees and water stages change; check the source before you rely on a number.
Before you rely on this. This field note is general information, not professional, engineering or legal advice. Every pool and every site is different. What Pool Era does on your project, how and with what warranty, is only what your written agreement says. Local codes and HOA rules change, so check with your city, county or HOA before you rely on anything here. Website terms
