The cost of evaporation
Evaporation is not just lost water — it is lost captured, paid-for and often treated water. Whether a suppression method is worth it comes down to a simple comparison: the value of the water it saves each year against what it costs to install. This page helps you frame that comparison.
Evaporation savings & payback estimator
Enter your own figures to see roughly how much water and money a method could save, and how long it might take to pay back. Indicative only.
Water saved
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m³/yr
Value saved
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$/yr
Simple payback
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years
How this is calculated & its limits: water saved = area × annual evaporation × reduction%; value saved = water saved × your water value; simple payback = your method cost ÷ annual value saved. It ignores discount rates, maintenance, salvage value, secondary benefits (algae/water-quality, power from floating solar) and any change in evaporation over time. It is not a quote — enter your own cost and reduction figures, and for authoritative, site-specific ROI, water-savings and CO₂ results, use the full AWTT calculator ↗.
Turning losses into a business case
Start with the loss. Estimate your annual evaporation depth from the calculation methods or your climate guide, then multiply by surface area — because evaporation is a surface process, loss scales with area, not depth. Multiply the volume you could save by the real value of that water (higher for treated, pumped or scarce supplies).
Then weigh it against cost. Cheap measures like monolayers and windbreaks have low capital cost but modest, weather-sensitive savings. High-coverage modular covers and geomembranes cost more but cut loss the most and last 20–25+ years. Floating solar can be justified by power revenue, with evaporation savings as a bonus. Compare the options fairly on the methods page.