Irrigation is considered to be a ne

Irrigation is considered to be a necessary precondition for the enhancement of agricultural production. The earliest approach to irrigation facilities was during 1960-1970 with the construction of large-scale multipurpose irrigation, flood control and drainage projects. To some extent, these projects were successful for flood control and protecting coastal areas from tidal bores and saltwater intrusion. But they played a minor role in irrigation development and only about 7 percent of the total irrigable area was covered by these very costly projects. Though the country has abundant surface water resources, particularly in the monsoon season, its flat deltaic topography and the instability of major rivers make large gravity irrigation systems both technically difficult and costly. On the other hand, during the dry season irrigation using surface water has become difficult or practically impossible owing to the limited availability of surface water. Therefore the use of groundwater for irrigation has become increasingly important.