Developed countries account for a quarter of the world’s irrigated area (67 million hectares). Annual growth of irrigated area peaked 3% in the 1970s and dropped down to only 0.2% in the 1990s

In Asia, almost 84% of the water withdrawal is used for agricultural purposes, compared to 71% for the world

The Indian subcontinent and Eastern Asia have the highest level of water withdrawal for agriculture with 92% and 77% respectively
In Latin America and the Caribbean, 73% of the water use is for agricultural purposes. The Guyana sub-region (Guyana and Surinam) and Southern sub-region (Argentina, Chile, Paraguay and Uruguay) have the highest level of water use for agriculture

In Africa, about 85% of water withdrawals are directed towards agriculture but this figure varies considerably from one region to another:

– Arid regions, where irrigation plays an important role in agriculture, have the highest level of water withdrawal for agriculture;

– The Northern region alone represents more than half of the agricultural withdrawal of the continent;

– The humid regions show the lowest agricultural withdrawals: 62% for the Gulf of Guinea and 43% for the Central region

The unit cost of irrigation development varies with countries and types of irrigated infrastructures, ranging typically from US$1,000 to US$10,000 per hectare, with extreme cases reaching US$25,000 per hectare. The lowest investment costs in irrigation are in Asia, which has the bulk of irrigation and where scale economies are possible. The cost expensive irrigation schemes are found in sub-Saharan Africa, where irrigation systems are usually smaller and the development of land and water resources is costly

Irrigation water withdrawal in developing countries is expected to grow by about 14% from the current 2,130 km3 per year to 2,420 km3 in 2030

Harvested irrigated area (the cumulated area of all crops during a year) is expected to increase by 33% from 257 million hectares in 1998 to 341 million hectares in 2030

(Information extracted from the World Water Development Report ‘Water for People, Water for Life’, 2003 and AQUASTAT/FAO)
Source: UNESCO Water Portal, February 2005