India is facing one of its most serious droughts in recent memory – official estimates suggest that at least 330m people are likely to be affected by acute shortages of water. As the subcontinent awaits the imminent arrival of the monsoon rains, bringing relief to those who have suffered the long, dry and exceptionally warm summer, the crisis affecting India’s water resources is high on the public agenda.

Unprecedented drought demands unconventional responses, and there have been some fairly unusual attempts to address this year’s shortage. Perhaps most dramatic was the deployment of railway wagons to transport 500,000 litres of water per day across the Deccan plateau, with the train traversing more than 300km to provide relief to the district of Latur in Maharashtra state.

The need to shift water on this scale sheds light on the key issue that makes water planning in the Indian subcontinent so challenging. While the region gets considerable precipitation most years from the annual monsoon, the rain tends to fall in particular places – and for only a short period of time (about three months). This water needs to be stored, and made to last for the entire year.

In most years, it also means that there is often too much water in some places, resulting in as much distress due to flooding as there currently is due to drought. So there is a spatial challenge as well – water from the surplus regions needs to reach those with a shortfall, and the water train deployed in Maharashtra is one attempt to achieve this.

The current crisis has led the Indian government to announce that it hopes to resurrect an ambitious plan to try and link the major river basins of the country, under the Interlinking of Rivers (ILR) Project. The scale and magnitude of this exercise, both financial (it is estimated to cost more than £100 billion) and in engineering terms (involving the transfer of 174 billion cubic metres of water annually) is unprecedented.

Critics suggest that it is unlikely to work and is likely to create further ecological and social disruption, especially due to the uncertainties in weather and precipitation patterns due to climate change. There is a risk that other alternatives, perhaps less dramatic in their scope, might be neglected in the rush for the big headline-grabbing schemes.

A specific way forward might be to work more directly with natural processes to secure the regeneration of water sources at the local level. In the dry plains, this involves the revitalisation of aquifers and the replenishment of groundwater through recharge during the monsoon, as has been attempted already in some regions. In the hilly areas, there is considerable scope for investment in spring recharge and source sustainability, as has been undertaken on a significant scale in the Himalayan state of Sikkim.

1.  Why is water planning in the Indian subcontinent so challenging?