In the 21st century, why does the forecast of a deficient monsoon send the same ripple of fear through India as it would 5,000 years ago? The short answer is that for almost 40% of the population, agriculture has not changed — it is still dependent on the “rain god”, or the South-West monsoon as it is known today.Here are the facts: about 46% of India’s net sown area (land on which cultivation is done at least once a year) is irrigated. The balance 54% is unirrigated and hence dependent on water that rains down from the clouds, mostly in the four monsoon months.Back in 1997, a government committee calculated that the Ultimate Irrigation Potential (UIP) for India was about 140 million hectares (Mha). That’s the possible extent of irrigation facilities that can be created. How much of this is actually utilized currently? In 2011-12, the net irrigated area was just 65 Mha, as per latest data available with agriculture ministry.Clearly, the single most important input needed by farmers — water — has not been provided for a very large number of farmers leaving them vulnerable to the erratic monsoon. That’s why the ancient fear still lurks in these modern times.Providing irrigation requires huge investment on the part of the government. Private capital is not going to get involved in a significant way because building canals demands long lock-in period for capital and low returns. In recent years, the investment in agriculture grew from 7.5% of the investment in the whole economy in 2004-05 to 7.7% in 2013-14. Within this, the share of government investment actually declined from 6.7 to 4.7%, while private sector share increased from 7.8 to 8.6%. The declining government investment in agriculture is the reason behind increasing vulnerability of farmers to water scarcity.The irony is that in all these years government did spend money on irrigation projects but not as much as needed and its usual inefficient manner. Between 2004 and 2014, the central government provided over Rs 53,000 crore to states for irrigation projects, according to a reply to a Parliament question. But out of 297 projects, 163 were running delayed, including some for over 20 years.So, how have the farmers been managing all these years? They have had no other option but to turn to pumping groundwater out through tubewells. In 1990-91, the share of tubewells in all irrigation was 30% but this jumped to 45% in 2011-12. In 1960-61, tubewells contributed just 1% to irrigation. Canal irrigation declined from 36% in 1990-91 to 25% in 2011-12.This does not mean that the tubewell dependent farmer is untouched by a failure of monsoon. Here is how it blows back on him too: his expenses for buying water from tubewell owners shoot up manifold in the absence of rain. Most small and marginal farmers do not own pumpsets and tubewells, they buy water from larger farmers.There is a larger hit the economy is taking because of lack of irrigation. Productivity is much lower in rain-fed cultivation. It ranges from one to two tons per hectare for foodgrains compared to up to four tons for irrigation. That’s why about 44% of India’s foodgrain production comes from 56% unirrigated land, while the irrigated land produces 56% output.According to Kapil Dev Sharma, formerly with the National Rainfed Authority of India, it is not necessary to just build canals. Very small interventions, like lined ponds, can also go a long way. Over 27 Mha land can be provided one supplemental irrigation by building such ponds that cost only Rs 18,500 per hectare.