Delhi to reuse 80 per cent sewage by 2027

With no new dams in sight, the draft Delhi Water Policy, 2013 calls for reuse of treated sewage to achieve water security in the capital

By Bharat Lal Seth
Published: Friday 03 May 2013


The population of Delhi is expected to be 27 million by 2051, roughly 10 million more than what it is today. But how to ensure everyone gets sufficient water even in the present time is a matter that remains unresolved. Formulating a water policy with the prime objective of “ensuring the long-term water security of the national capital territory (NCT) of Delhi even under conditions of external flux”, is the first step in the direction taken by the Delhi Government.

The draft document (pdf), acknowledges that the large dams planned in the upper reaches of the Yamuna basin are unlikely to be operationalised in “15 to 20 years”, if at all. The policy has, therefore, endorsed reuse of treated sewage, starting with a target of 25 per cent of all sewage generated in 2017, to more than 80 per cent in 2027 to augment water availability. It has taken a dire situation, when new sources are getting increasingly harder to tap, for the government to finally embrace treated sewage in their menu of options, a long established, financially prudent and technologically viable solution. The number crunching that the Centre for Science and Environment, a New Delhi non-profit did in its seventh State of India’s Environment Report, titled Excreta Matters, showed that putting our existing water and resulting sewage in a loop can help meet our future demand, if not entirely then at least to a large extent.

Missing nuts and bolts

The draft policy is silent on how, for which purpose and where the sewage will be used. Although this is beyond the scope of the document, a logical step will be to conduct a feasibility study on how this target can be met. Other options laid out in the policy include upping the ante with rain water harvesting, conservation of local water bodies, and curbing demand by improving use efficiency as well as reducing distribution losses.

The task of drafting the water policy was given by the Delhi Jal Board (DJB) to the Delhi chapter of the NGO, Indian National Trust for Art and Cultural Heritage or INTACH, in April 2011. The non-profit has convened three workshops since. At the fourth meeting, held on April 22 last month, chief secretary Deepak Mohan Spolia called for a 30-day window to take on board other suggestions on the draft. All the stakeholders have until end May to submit their comments, after which a presentation will be made to Chief Minister Sheila Dikshit. Thereafter it is hoped that the policy will be announced.

The policy has set some targets to achieve water security (See 'Draft policy statements'). “There is some talk to set up a State Water Commission with the powers to override all other agencies, along with a task force to convert the policy statements into actionable programmes,” said Manu Bhatnagar, principal draftsman of the policy and head of the natural heritage division at INTACH.

Draft policy statements
Statement 1: Priority in Water Allocation

The priority in allocation of water resources would be in the following sequence:
  • Drinking water and human freshwater use
  • Power Sector
  • Industry
  • Ecology
  • Irrigation

Statement 2: Demand Management

Delhi will reduce the present per capita consumption norm of 172 lpcd by a minimum of 10 litres every decade.

Statement 3: Recycled Water Resource

Delhi will frame targets to increase its recycled wastewater use:
  • to 25% by 2017
  • to 50% by 2022
  • to minimum 80% by 2027

Statement 4: Access to Water for All

Delhi will ensure access to water to every resident of the territory for their minimum water requirements in line with Article 21 of Constitution of India and in accordance with UN Resolution to which India is a signatory.

Statement 5: Controlling Distribution Losses

Distribution losses will be curtailed at all levels to achieve maximum losses less than 10% by 2025.

Statement 6: Aquifer Management

Aquifer exploitation and recharge (naturally and artificially) will be neutralized by 2020 and attain full recovery to 1990 levels by 2030.

Statement 7: Database Management

Strive to achieve 100% metering by 2020, inclusive of return flows or sewage.

Statement 9: River Related Issues

Set targets to restore river water quality to bathing quality by 2020 and carry out ecological monitoring. Aim is to reduce abstraction of river water from Yamuna River by increasing its reliance on recycled water resources.

Statement 10: Public Education and Awareness

City agencies will initiate campaigns to raise the level of public literacy about Delhi’s water endowments, constraints, challenges and use of resources

. Source: Draft water policy for Delhi

The draft has stressed on curbing demand as well as tapping the so called alternatives, be it treated sewage or rainwater, to augment supplies since the proposed dams and water storage reservoirs are being opposed on various fronts. The 150 metre high proposed Renuka dam on Giri river, a tributary of the Yamuna, is held up for lack of statutory clearances by the Centre. The Kishau dam on the Tons, also a tributary of the Yamuna, and the Lakhwar Vyasi dam on the main stem of the Yamuna are at different stages of development; both are seeking statutory approvals.

But is the national capital really in need of any of these projects? Delhi’s 2051 water demand at the norm of 172 litres per person per day works out to 1,018 million gallons per day (MGD). Currently, DJB has the potential to supply 930 MGD (see 'Delhi’s different water sources'). After taking into account losses of 15 per cent, actual supply would be 790 MGD, although leakages are anywhere in the range of 25 to 40 per cent. The accepted thumb rule for sewage generation factor is that 80 per cent of water supplied is returned as sewage. This means Delhi will generate 550 MGD of sewage, of which “under Upper Yamuna Basin Agreement, NCT Delhi is supposed to return 250 MGD to the Yamuna River, leaving 300 MGD available for recycling usage and thus closing the demand supply gap”, says the draft policy. Treated sewage can be used to top up water bodies, crop irrigation, and horticulture, fire fighting, industry or even for recharging ground water, but only after ensuring the discharge meets the requisite water quality.


As per the water sharing agreement for Yamuna signed in 1994 with Uttar Pradesh Haryana, Rajasthan and Himachal Pradesh, the NCT was allocated 724 million cubic metre of water each year. Of this, it can tap 580 MCM during July-October period, and 68 and 76 MCM from November to February and March to June respectively. According to the water policy, “present utilization of the allocation in the monsoon season is only 282 MCM, and thus 298 MCM goes unutilized for lack of storage capacity in Delhi or by way of non-existent upstream reservoirs in the Himalayas.” How to make use of these flood waters is a moot point. Environmentalists have called for smaller storage structures and more rainwater harvesting initiatives, while the Union Ministry of Water Resources and the city agencies are in favour of larger storage structures such as the proposed dams in the upper reaches of the Yamuna. “This agreement may be reviewed after the year 2025, if any of the basin States so demand,” was what the chief ministers of the five riparian states agreed upon in 1994. “Uttar Pradesh will not surrender any water, and Rajasthan and Haryana will want more. So Delhi will be lucky to hold on to its share,” says Bhatnagar. Even if the Renuka project comes through, thanks to other alternative interventions mentioned in this draft, Delhi will be in the position to use its share of the water to improve the flow in the river, he adds.

On the ground water front, it is estimated that each year the national capital territory extracts 479 MCM, whereas the natural recharge is around 281 MCM; annual extraction is 170% of recharge. The quality of the water is another area of concern and has been linked to the untreated discharged of sewage into open drains. The draft is clear in stating: “NCT Delhi does not possess adequate natural water resources of its own in the form of rivers or ground water and is greatly dependent upon reservoirs situated at very long distances on the interstate rivers of the Ganges and Indus basins.” There is a need to change this mindset by stressing on local water bodies, Delhi’s own water endowment and existing treated sewage potential, which has been hitherto untapped.

Better late than never

Although the national water policy 2002 has now been superseded by the new National Water Policy 2013, the earlier policy had stipulated that each state must formulate its own water policy within a period of two years. It took the Delhi government more than a decade to kick start this process. According to the draft, “presently, Delhi cannot be said to have a water policy”. Delhi's water utility, DJB, which is responsible for water supply and sewage treatment and disposal, has slowly begun to invest in reuse of sewage, reducing leakage losses, and support rain water harvesting initiatives, but these have been criticised for not making much headway and lacking targets. The draft also mentions that “fledgling efforts at awareness raising are made occasionally but amount to tokenism”. It yet remains to be seen how these guiding principles will be followed, the plan executed and the targets achieved.

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