Using additives with water absorbing characteristics enables us to increase the amount of water in natural basins and significantly decrease the amount of water for agricultural usage. Despite various additives already existing, they are yet to be commonly used due to high cost price, complex technology, toxic impact and instability in biological and atmospheric conditions. However, the «Natlen» composite, which is a naturally based additive, is ecologically safe. It has a long shelf life, is cheap and provides high antifiltering rates. The composite is eruptive with dispersity of any type and is jelly when boosted. In an antifiltering layer it never cracks under static and dynamic influences. It has no seam and is resistant to aggressive liquids. It is ecologically safe. «Natlen» composite is recommended for building water basins in pastures, where it can particularly be used to satisfy the demand for drinking water for cattle.