Naireeta Services banked floodwater underground to fight drought

In parts of rural Gujarat, India, farmland faces two opposite disasters in the same year: monsoon rains waterlog and salinate fields for months, and then a seven-month dry season leaves the same land parched. Standing floodwater dissolves minerals in the soil, leaving a salty crust once it evaporates that prevents future rain from penetrating the ground at all, compounding the damage each year.

The standard response treated the two problems as entirely separate, each needing its own expensive fix: flood-drainage infrastructure to clear the monsoon water away, followed by irrigation systems or well-drilling to supply water during the dry months that followed. Building and maintaining two unrelated systems — one to remove water, another to find more of it a few months later — was a cost most smallholder farmers, particularly women without secure land rights, could never afford.

Biplab Ketan Paul, later working with Trupti Jain's Naireeta Services (founded 2011), developed the bhungroo — a filtration pipe that injects excess monsoon floodwater down through the salty surface layer and into the water table below, banking it underground rather than draining it away or letting it evaporate. A single unit can hold roughly 40 million litres. During the dry season that follows, farmers pump the same banked water back up for irrigation, using the flood itself as the source of the water that gets them through the drought.

Used a filtration pipe to inject floodwater underground into the aquifer, banking it there until the dry season, so the flood itself became the drought's water supply.

Injecting floodwater underground removes waterlogging and salinity in one action.

Underground storage prevents evaporation, preserving water for months.

Using the aquifer as storage avoids separate reservoir or well costs.

The same water that caused flooding becomes the dry season's irrigation supply.

When a resource swings between surplus and scarcity on a cycle, bank the surplus in existing storage to cover the scarcity, instead of building two separate systems.

A single bhungroo unit serves about five families for at least 25 years, and land that used to be barren or capable of only one crop a year can now support two to three crops annually. The technology won the 2017 Buckminster Fuller Challenge and, through Naireeta Services, has reached farmers across India, Bangladesh, Vietnam and parts of Africa, with tens of thousands of acres brought back into reliable cultivation.