A water-repellent earth material having grains formed with silicone coating; is made by mixing the earth material with an emulsion of silicone oil in water and drying. The earth material may be selected from the group consisting of soil, sand, gravel, pebbles, silicon-containing combustion ash of household refuses and silicon-containing combustion ash of industrial refuses. The earth material may be used to form a water-repellent ground surface layer, a water-repellant underground layer or a water-repellent enclosure for various purposes.
