With the monsoon season approaching, here comes another chance for Delhi to increase its groundwater level, by utilising the rainwater harvesting system. Depleting groundwater levels of the city and its surroundings is no longer news. Access to piped water remains a distant dream in many villages or even slums and unauthorised colonies, where residents still rely on water tankers. These localities also have to rely on illegal boring, which results in fast disappearance of groundwater.
To address this, the Delhi government has adopted several measures. One of them is the rainwater harvesting (RWH), a cost effective system using an age old technique. Many Indian cities have achieved success by implementing this. Tamil Nadu had in 2015 yielded positive results after sustained efforts over 15 years. The project was started by then Chief Minister J Jayalalithaa in 2001.
For two years, the AAP government has been working on RWH and taking measures to ensure this is implemented properly. On an average, Delhi gets 617 mm rainfall a year. During monsoon, Delhi Jal Board (DJB), which looks after the RWH schemes, aims to ensure that the water received till September is utilised as much as possible, for non-potable use and groundwater recharge.
To implement the RWH system from the grassroots, the government revised the building byelaws for Delhi and Delhi Water & Sewer (Tariff and Metering) Regulations in 2019. Owners of existing and new properties (govt and pvt) measuring 100 sq m and above had to install RWH structures in about a year, by March 31, 2020, for properties constructed after July 28, 2001, and September 25, 2020, for those constructed before July 28, 2001. Guidelines also stipulate that Urban Local Bodies (ULBs) should ensure that all government buildings (Central/State/ULB) must have RWH structures. To make sure this is taken seriously and adopted actively by residents, the government incorporated a system of providing rebates as well as issuing a penalty for not following the order.
Penalty and incentive
As an incentive, for installation of RWH structures, DJB offers compliant owners a financial assistance of 50 per cent of the cost subject to a maximum of Rs 50,000 and a rebate of 10 per cent on water bills. Those failing to install are penalised up to 50 per cent of the total water bill amount. As per DJB, between July 2017 and July 2019, a total rebate of Rs 32.5 crore was provided to consumers reporting functional RWH structures, while Rs 56.7 crore was generated in penalties.
Furthermore, new water connections are given only when property owners provide a certificate of installation of a functional RWH structure. Rain centres are established in each district by DJB, managed by officials of the board.
Last year, DJB issued orders to set up 12 rain centres to facilitate adoption of RWH systems in the monsoons. While 11 of these will be at the district level to provide guidance and technical expertise on installation, five will work on the central level.
In 2020, Delhi government said it will adopt the cost-effective model of RWH currently implemented in the tribal-dominated Dungarpur district of Rajasthan. The announcement was made by Water Minister Satyendar Jain, who said the Dungarpur model was innovative and centred on routing rainwater to a bore well, instead of a regular rainwater-harvesting pit. This model costs just Rs 16,000 compared to the conventional one, which costs between Rs 50,000 and Rs 1 lakh per household.
The Delhi Development Authority (DDA) will revive defunct bore wells in parks and gardens within a month to facilitate rainwater harvesting. After identifying waterlogging points on roads, parks and other places, it will put a system in place to divert rainwater to underground reservoirs. Rainwater from roads will be diverted to reservoirs in 50 parks through kuchha and pucca drains built for this purpose.
“We have concrete plans and a proper roadmap for large scale implementation of RWH in Delhi. We are doing it in schools and other government bodies. What we can do at max for the societies and private buildings is motivate. We are offering rebates and financial help up to Rs 50,000. Schools are doing it well and have given very good responses. PWD and DJB buildings have implemented it,” said an official from DJB.
However, Manu Bhatnagar, Principal Director, Natural Heritage Division of INTACH, is of the opinion there is no sufficient evidence to claim or be assured how effective these measures have been because the water table of Delhi has been consistently falling. “The smaller the plot, the less effective the water harvesting for reasons that there’s hardly any space to build the structure. Moreover, maintenance of the structure has not been taken seriously. After a couple of years, they are clogged and do not perform effectively. But nobody bothers maintain them afterwards. They should have more water harvesting at community level, at colony level. At a low-scale level rather than individual house level. The government of Delhi needs to think big and large thinking will achieve some noticeable results.”
Long road ahead
A recent DJB report states that 4,124 schools and colleges have RWH systems, while installation in the remaining 407 eligible institutions will be done in a phased manner. Similarly, 3,705 government buildings can now harvest rainwater, with 1,767 yet to do so. More than 13,286 DJB customers have been penalised for non-implementation of the RWH rule and fined a cumulative Rs 74 crore.
Rumi Aijaz, Senior Fellow at ORF and responsible for conduct of urban policy research initiative, said the challenge is to take forward the policy and the schemes. “Having a law and developing a policy and creating an implementation mechanism is 80 per cent good. The government has done a lot of work for the development in the RWH sector, but many challenges are experienced.” he added.
Delhi’s efforts to implement RWH and recharge groundwater face multiple challenges. First is abrupt rainfall even in monsoon. “Delhi in many seasons experiences deficit rainfall. The deficit is 141 million gallon every day, production is 935 million gallons, while demand is 1140 million gallons a day,” Aijaz added.
Another issue, Aijaz pointed out, is widespread growth of structures, buildings and colonies and their unwillingness to embrace this idea. “More systematic structures are needed. In some places, it exists but is not maintained. Cost is also a factor. It’s a difficult area of work. It’s simpler in open areas, parks, low lying areas, flood plains to create RWH structure. There are many areas where it is not being tapped. Only about 30% to 40% of the potential is utilised. There is no proper distribution in the city of RWH structures. In some parts, groundwater level is already low, while in some it’s better.”
The pace of work has been slower in the last two years due to the pandemic. Aijaz believes on paper, the government has done well, but ground reality says otherwise. Another factor affecting the pace is budget. “DJB had a deficit budget. To maintain one structure, around Rs 40,000-Rs 50,000 is spent annually. The government is supporting, but that’s not sufficient,” Aijaz noted.
Has enough been done?
Bhatnagar feels not enough is done. Apart from storing, focus should also be on reducing the amount of water used in Delhi. “If we are doing some work with 20 litres, we should be able to do it with 10. Only then groundwater extraction will come down. When both these are in balance the amount recharging and the amount extracted you can have some stability in the water table, which is otherwise falling,” he added.
Citing the example of Hauz Khas Lake, which had completely dried in 2003 and was then treated with sewage water from Vasant Kunj STP, he said: “The water which is found now, you can just chlorinate and get drinking quality. The lesson I’m drawing is rainfall is occasional. Nowadays sewage water is treated and the quality of treated water is also going up. When you use treated sewage to fill water bodies, you find that you are able to recharge it daily. Rainwater comes once in a while. It’s my recommendation that the structures should be used for both sources — rainwater as well as recycled water. And that way we can build our water table.”
Aijaz stated at the managerial level a lot of things are done, but the push needed from DJB or Delhi government doesn’t always come. “Success of the RWH initiative depends on public cooperation. People are also facing difficulties to implement it and the government has to provide solutions apart from financial support. If you don’t facilitate, guide then private people won’t be willing to invest or collaborate,” he added.
What is RWH
Rainwater harvesting is a process or technology used to conserve by collecting, storing, conveying and purifying rainwater that runs off from rooftops, parks, roads, open grounds etc
Why harvest rain
In areas where groundwater supply is inadequate and surface resources are either lacking or insufficient, rainwater harvesting offers an ideal solution. It helps in utilising the primary source of water and preventing it from flowing into sewer or storm drains, thereby reducing the load on treatment plants. It reduces urban flooding.
Disadvantages of rainwater harvesting
Requires regular maintenance
Requires technical skills for installation
Limited or no rainfall can limit supply of rainwater
If not installed properly, it may attract mosquitoes and lead to waterborne diseases
Storage limitations are an additional drawback
Popular methods of rainwater harvesting
How many, when & where
A recent DJB report states that 4,124 schools and colleges have RWH systems, while installation in the remaining 407 eligible institutions will be done in a phased manner. Similarly, 3,705 government buildings can now harvest rainwater
On an average, Delhi gets 617 mm rainfall a year. During monsoon, Delhi Jal Board, which looks after RWH schemes, aims to ensure the water received till September is utilised as much as possible, for non-potable use and groundwater recharge