Its origin is just 50 kilometres from the IT city, Bengaluru. It is a tributary of the Arkavathi River, the source to the Thippagondanahalli reservoir, which used to supply 30 per cent of the water needs of the garden city two decades ago. Now it is non-existent, its over 100-stream network dried up, and the groundwater in all the villages surrounding the river basin having dropped drastically.

We are talking about the erstwhile Kumudvathi River in Karnataka, the drying up of which forced a large section of the rural population to either alter the cropping patterns and shrink the area under cultivation or abandon their lands and migrate to Bengaluru in search of employment.

The year 2007 also saw an acknowledgement of the growing water crisis, with Bengaluru facing a 20 per cent shortage of fresh water supply, the Thippagondanahalli reservoir fed by Kumudvathi River going dry.

The case of Kumudvathi River is, however, not alone. Many rivers, both small and large, across the country, have either dried up or are facing far less flow, with depleting groundwater in the surrounding regions jeopardising agriculture besides encouraging the ensuing rural-urban exodus.

The year 2016 saw a third of all districts in the country being declared as drought-affected. In Maharashtra, lakhs of litres of water were transported by trains to address this drought. This year it is the reverse, with floods reported across many states of the country.

What is causing this phenomenon? While many factors come to the fore, the chief pointers are deforestation, urban encroachment, quarrying and yes, over-exploitation of groundwater; in short, mindless, irresponsible environmental degradation.

The natural hydrological cycles that operate in a region depend on the natural activities of people living at the river basin. For availability of water and sustained river flow in a basin, there needs to be an understanding of natural processes such as rainfall patterns, topography, drainage network as well as the geohydrological situation. The imbalance of hydrological cycles depletes groundwater as well as surface water over the long term, even when there is good rainfall.

Observing this scenario, February 2013 saw a large team of volunteers from the Art of Living (AOL) taking it up as a challenge and deciding to devote their weekends to travel to the villages in the river basin of Kumudvathi and start working on the plan of rejuvenating it by using a scientific methodology. Going by this approach, the volunteers built 439 boulder checks, de-silted over 20 traditional stepwells, constructed 434 recharge wells and 71 water pools, built 45 recharge borewells, planted more than 425,000 saplings, besides spreading awareness to over 75,000 people residing in over 100 villages surrounding the river basin.