Pond Water Evaporation Calculator
Estimate daily water loss based on local climate conditions
Estimated Water Loss
*Results are estimates. Actual rates vary based on sun exposure, waterfall splash, and water temperature.
Is Your Pond Leaking or Just Evaporating?
Seeing your pond water level drop can be alarming. While a leak is possible, evaporation is often the primary culprit, especially during hot, dry, or windy weather. This calculator uses empirical climate formulas to estimate how many gallons your pond might lose naturally to the atmosphere.
Primary Factors Driving Pond Evaporation
- Temperature: Warmer air holds more moisture, increasing the rate at which water molecules escape the surface.
- Humidity: In dry air (low humidity), evaporation happens much faster because the air has a higher capacity to "soak up" water vapor.
- Wind Speed: Wind carries away the saturated air directly above the water surface, replacing it with drier air and accelerating the drying process.
- Surface Area: A large, shallow pond will lose more total volume than a small, deep pond due to more water-to-air contact.
Example Scenario
If you have a 1,000 sq. ft. pond in a climate with 90°F heat, 30% humidity, and a light breeze of 5 mph, you could lose approximately 0.32 inches of water per day. That translates to roughly 200 gallons of water lost every single day just to the air!
The "Bucket Test" Strategy
To confirm if you have a leak, fill a bucket with pond water and set it on a shelf in the pond (keeping the water levels the same). Mark the water level inside the bucket and in the pond. After 24 hours, if the pond level dropped significantly more than the bucket level, you likely have a leak. If they dropped the same amount, it's just evaporation.