Depleting Indian water reservoirs need rains to prevent crop loss: Govt

India's reservoirs are depleting fast and monsoon rains need to pick up now if they are to have enough water to prevent a drop in output of major winter crops such as wheat and rapeseed that are sown from October, a senior government official said.

Rains in India, the world's second-biggest rice, wheat and sugar producer, were 15 per cent below average in the week to July 16, an improvement from the previous week's shortfall of 41 per cent but still 29 per cent deficient since the start of the season in June.

Water levels in the country's 85 main reservoirs in the week to July 17 were at 26 per cent of capacity, down 16 percentage points from the year ago. The latest levels are lower than the 10-year average of 30 percent for the week.

"Reservoir levels must start going up from now on, otherwise the winter crop will suffer," said A B Pandya, chairman of the state-run Central Water Commission, which oversees irrigation, flood control, drinking water supplies and overall water management in the country.

"A fairly quick revival of rains is crucial to compensate for the fact that we have not had much rainfall this season," Pandya said in an interview on Tuesday.

Indian farmers depend on June-September monsoon rains, as half of the country's farmland lacks irrigation facilities. Farmers mainly plant rice, corn, cane and soybean in the rainy months of June-July. Harvest starts from September.

A healthy reservoir level is crucial to irrigate crops sown from October. Also, a dry spell drains moisture out of the soil.

"In a vast country like India, we cannot depend on ground-water irrigation which in any case plays a very small role. Sub-normal water levels at reservoirs could delay sowing and impact yields," Pandya said.

Although India is sitting on huge stockpiles of rice, wheat and sugar, crop loss will hurt small and marginal growers, the bulk of the country's 263 million farmers.

Lower productivity or crop damage leads to widespread penury in the countryside where nearly half of India's 1.2 billion people depend on agriculture to eke out a living.

The country may also cede its position as top rice exporter to Thailand.

A clear picture about water reservoir levels would emerge only by end-September, Pandya said.

Any further delay in revival of rains could also stoke drinking water shortages.

"So far we have not had any drinking water crisis. If, God forbid, anything should happen, ensuring drinking water to people will take priority over irrigation, hurting agricultural production," Pandya said.

The federal government has asked the state governments, especially of Punjab, Rajasthan, Maharashtra and Madhya Pradesh to focus on optimum use of water.

"Of late rains have been better but to avoid any delay in sowing of the winter crops, monsoon should now become more vigorous and stay that way for rest of the season," he said.