Information on the volume of water intake and extent of irrigated areas available for different countries allows calculation of specific water withdrawal for irrigation under different physiographic conditions.

Naturally, the smallest values for specific water withdrawal are observed in the north; for instance, in northern Europe they are between 300-5000 m3/ha while in southern and eastern European countries they amount to 7000-11000 m3/ha. The returnable waters are equal to approximately 20-30% of water intake.

In the USA, specific water withdrawal for irrigation is estimated by different authors to be between 8000-10,000 m3/ha and returnable waters at some 40-50% of water intake. In the countries of Asia, Africa, Central and South America, where there is a great variety of climatic conditions, crop composition and watering techniques, the values for specific water withdrawal range from 5000-6000m3/h to 15,000 to 17,000 m3/ha and in individual regions of Africa, 20,000-25,000 m3/ha.