Water Innovation #574: Managing salinity with 'Bhungroo' or 'the straw'
“Bhungroo” or ‘the straw’ is an innovative concept of injecting the excess surface water below the soil and storing it in a subsoil aquifer. It works on the principle of difference between the densities of storm water and water in underground aquifers. This stored water can be retrieved and reused for winter & monsoon cropping.
Perforated pipes are inserted in the land. Once rainwater/storm water gets collected (i.e. the land gets water logged), these pipes help inject the collected water into the subsoil, at a depth where the water density is higher than storm water density. The lighter rainwater can then float above the more dense subsoil water. It can then be pumped out and used for irrigation.
Bhungroos can be especially useful to farmers in salinity-affected or flash flood-prone areas with scarce and erratic rainfall. In this video, Biplab Paul of Lokvikas, India, demonstrates how they work.