Pools Use Less Water Than You Might Think
Updated for 2026 — practical, real-world guidance for California backyards
Pools can use a meaningful amount of water — but in many homes, the biggest outdoor water users are still landscape irrigation and evaporation from hard-to-cover water surfaces. The goal isn’t panic; it’s efficiency.
Quick takeaway: EPA WaterSense estimates an uncovered ~500 sq. ft. pool can lose 12,000–31,000 gallons/year to evaporation depending on climate. A well-used cover is the single biggest step you can take — solid covers can reduce evaporation by 90%+.
Where Pool Water Actually Goes
- Evaporation (usually the #1 driver in hot, dry, or windy weather)
- Leaks (auto-fill can hide them for months)
- Splash-out and water displaced by play
- Draining/refilling (sometimes needed, but often avoidable with good chemistry and filtration)
The Numbers
These are ballpark figures meant to help with decision-making. Your results vary with wind, temperature, shade, pool heat, and how often a cover is actually used.
| Scenario (500 sq. ft. pool) | Estimated evaporation-related water loss | What to do about it |
|---|---|---|
| Uncovered pool | 12,000–31,000 gal/year | Use a cover consistently; add wind protection where practical. |
| With a solid cover (used regularly) | Often 90%+ lower evaporation loss | Choose a cover you’ll actually use (reel/automatic helps). |
Note: Total pool water use can be higher than evaporation alone if there are leaks, frequent backwashing, or unnecessary draining/refilling.
How to Cut Pool Water Use (Practical Checklist)
- Use a pool cover whenever the pool isn’t in use (especially overnight and during wind events).
- Check for leaks and make sure the auto-fill valve isn’t stuck on.
- Don’t overfill — keep the waterline at the correct level to reduce splash-out and waste.
- Reduce wind (hedges/screens/windbreaks) where it makes sense — wind dramatically increases evaporation.
- Avoid drain-and-refill when possible by keeping water chemistry balanced and filtration maintained.
Pool vs. Landscape: The Fair Comparison
In many California neighborhoods, urban water use changes the most with weather because outdoor irrigation can be a large share of household demand (and can exceed indoor use in hot, dry areas). If you’re comparing “pool vs. yard,” compare the pool’s evaporation + maintenance water to your actual landscape irrigation use — and consider converting thirsty areas to water-smart planting.
Local Restrictions (Important)
Rules on pool filling/refilling can vary by city and water retailer — especially during drought stages. If you’re planning a new pool or need a refill, check your local guidance first.