Water is the most widely seen, profoundly used, abundantly available yet scarce, simply complex commodity, without which, life on earth is impossible.
1950 onwards, sweet water on earth is under ever increasing, serious pressure due to various known reasons.
Evaporation Retarding Experiments for conserving sweet water began hundred years ago. Real movement caught the world’s attention since 1960.
Various options were tried to reduce evaporation like...

Coloring of water...
Lowering water temperature by churning water column with bubbles...
Erect Wind Barriers surrounding to water body including floating barriers...
Using lighter floating objects/materials like ...
EPS Balls, Hollow PVC Balls or saucer like objects, Surface covers etc.
Spread materials like Rice husk, Oils, Fatty Acids Alcohol Compounds. etc…

Each material and method had limited success at local level, yet was not applied ongoingly for Evaporation Retardation.
Out of various materials and methods tried, Water Retardation by spreading non-toxic chemical material was found to be most practical and promising.
Focused research, at every level led to certain conclusive results in India.