Using small ping pong balls ...

Using small ping pong balls that are common in the United States can be very costly for us.

If you live in an area where there is oil pollution, you will find that there is always a layer of fat or hydrocarbon oil on the surface of the water, so this environmental experience should be used as an opportunity.

In other words, to prevent wastage and evaporation of water from the surface of rivers, lakes and dams, you can look for new technology such as the production of a type of polymer or fat that when sprayed on the surface of the water and placed on the upper surface of the water as a coating It acts and prevents direct sunlight on the surface of the water, thus minimizing water evaporation.

However, this polymer or fat should not affect water quality. Also, whenever you want to use that water for drinking or industry and agriculture, all you have to do is remove the water surface and take your water from the bottom layer, for example, 50 cm below the river and lake surfaces.

In other words, you can insert the hose connected to the water pump in the bottom layer of the water surface and take the used water from a greater depth.