Rooftop rain water harvesting can end Delhi’s water crisis

In 2002, the state of Tamil Nadu made rooftop Rain Water Harvesting (RWH) mandatory in housing structures, ensuring that no building would be constructed without making structures for water conservation. 

Rooftop rain water harvesting can end Delhi’s water crisis

In 2002, the state of Tamil Nadu made rooftop Rain Water Harvesting (RWH) mandatory in housing structures, ensuring that no building would be constructed without making structures for water conservation. The resultant benefits were here for everyone to see. By 2005, the water table levels had gone up by 20 percent. The temple tanks around the city become half-filled with water. Now, let us shift focus to Delhi and the National Capital Region.

In 2009, the Central Ground Water Authority (CGWA), a body under the Ministry of Water Resources sounded an alarm to all states to adopt the rooftop rain water harvesting systems in government institutions. In Delhi, this process is still restricted to only a few such institutions. Even though the Centre provides financial and technical support for such projects, only 18 states have so far been able to implement the direction. In most states, the initiative is yet to catch on.

While in the private sphere, only a few Resident Welfare Associations in South Delhi have made good use of the technology leaving most citizens unaware of the veracity of depleting surface water resource.

India is the largest user of ground water in the world, say World Bank estimates. Nearly 50 percent of the drinking water comes from underground sources. So much so, that ground water has been called the vital lifeline for the country.

Delhi has also been using ground water extensively to meet its per capita water consumption, which is about 1,100 million gallons (mgd) of potable water per day. The Delhi Jal Board (DJB) supplies around 800 mgd water across the city. This demand is projected to touch around 1,400 mgd by the end of the 12th Five-Year Plan in 2017.

What is Rooftop Rainwater Harvesting?

Rooftop rainwater harvesting (RWH)​ is a relatively affordable way to capture and store rain water for various purposes. It is also used to recharge ground water aquifers. It is a low cost and an eco- friendly technique for preserving each drop of water as it falls by guiding rain water to bore wells, and pits. Currently, it is the only way to reduce community’s dependence on ground water. According to figures, Delhi NCR receives 611 mm of rainfall on an average annually and the number of rainy days are as low as 20-30. Still, rainwater harvesting is a workable model to gather water from precipitation and to save it from collecting into the seas.

To know more about this technique, you can visit the following sites:



Is Delhi lagging behind?

The Delhi High court had issued a direction to Delhi Jal Board (DJB) to promote and make RWH attractive in private buildings in the city. But, sources within the civic body have stated that the initiative has not picked up too well in the city. Some have pointed out that the changes in the building by-laws have not been implemented on the ground.

The civic body had taken up initiatives to promote RWH by offering households a rebate of 10 percent on water tariff, 15 percent if houses install water recycling systems. A grant called – MyDelhiIcare fund of Rs. 5 lakh has been set up for the purpose of RWH. The then Delhi Chief Minister Sheila Dikshit had also launched Minister’s Best Rain Harvester Award.

Why Delhi couldn’t replicate Tamil Nadu Model?

Despite the financial and technical aid provided by the civic body, what makes Delhi stand behind on accepting rain water harvesting? Water activists in the city feel the government is not taking matters seriously. “The government is not serious. They do not know Delhi’s potential for water harvesting. The government could have started with all government institutions for RWH. They could have enforced it on commercial places such as malls, multiplexes, railway stations, parks, etc,” said Himanshu Thakkar, founder, South Asia Network on Dams, Rivers & People.

‘Change building by-law policies’

The Water Ministry has urged the States to make rooftop rainwater harvesting mandatory in by-laws for new buildings. Even though it has been implemented on paper, there is nothing to show on the ground. According to the building by-laws laid down by the Municipal Corporation of Delhi, any structure having more than 200 yards in area must be rainwater harvest certified. “When people apply for provision of sanction of maps for buildings in Delhi, they pull the plug on the process just before it reaches the final stage of approval. Once the process is initiated, it shows as passed,” said Yogendra Mann, Director Press information, MCD.

‘Water is a state subject’

Another issue with the workability of rooftop rainwater harvesting systems has been pointed out by Himanshu. “Practically, Delhi has very little roof space. Most people in Delhi do not own roof spaces.” But the most important hindrance remains the mind set and lack of awareness. “This is also because the government has made it clear that water is their own business, which is a colonial mindset. They have not encouraged participation from local people, RWAs or local groups. So the people don’t feel responsible for its conservation,” he said.

Illegal boring giving rise to quality concerns

Delhi’s groundwater analysis has shown that the water being extracted from underground now contains high levels of fluoride. Improper disposal of sewage water around the wells has led to high levels of nitrate content in West, South-West and some parts of New Delhi. Hence, when the DJB is unable to provide clean drinking water to all areas, people dependent on direct extraction from wells and tankers, leading to consumption of contaminated water.

“The growing depletion of ground water has hit us more in the last two decades. While people can’t compromise on water usage in urban areas, many have started extracting water illegally, digging deeper bore-wells for personal usage,” said Aditya Sharma, co-founder RAIN Water, a Jaipur-based initiative.

​Water Insurance: Need of the hour​

He also adds, “Rain Water Harvesting is not a remedy to the problem, but a kind of insurance. We need to insure against some degree of scarcity of water.” We must understand that conservation of this life resource is also an individual responsibility. Citizens can no longer depend on government initiatives for access to water. The declining level of fresh water and increasing demand, the need has arisen to conserve and effectively manage this precious resource for sustainable development. Let us begin from our homes.

For more details and queries on rain water harvesting, please contact the Rainwater Harvesting Assistance Cell on 011-23678380-82 extn. 246,240 or you can email them at;;