Shallow Tubewell Irrigation in Nepal: Impacts of the Community Groundwater Irrigation Sector Project (Final Report)

Abstract

Irrigation for agriculture accounts for about 70% of all the world’s freshwater withdrawals and 90% of water consumption. An estimated 301 million hectares (ha) of the world’s land is irrigated, and 38% of this total is equipped for irrigation with groundwater (footnote ). The countries with the largest land areas irrigated by groundwater are India (39 million ha), People’s Republic of China (19 million ha), and United States (17 million ha). Groundwater irrigation is growing both in terms of the land area served and as a percentage of overall irrigated land. This has led to problems in places where the rate of exploitation is greater than the rate at which groundwater is being replaced. The groundwater basin is a common resource, and excluding its multiple users is difficult and costly. Groundwater has often provided a regular and timely supply of water for irrigation. Studies indicate that farms irrigated by groundwater have higher crop yields than farms irrigated by surface water.