Transparent methodology
1. Reference evaporation
One average annual rate (mm/year) per climate zone: Andalusia 1,500, Catalonia 1,200, Southern Italy 1,200, Po Valley 1,000, Occitanie / PACA 1,100.
2. Lost volume
Volume (m³/year) = surface (m²) × evaporation (mm) ÷ 1000.
3. Cover effect
Default 96% — Nevada field test (2024, AWTT / Hexprotect AQUA). In Europe: 80–96% depending on wind and geometry.
4. Water saved
Saved volume (m³/year) = lost volume × reduction rate (96% default), rounded. Converted to litres (× 1,000) and Olympic pool equivalents (2,500 m³ each).