Having issued new, simplified designs for RWH structures, the water utility has given residents time till June 30 2016 to install the same, failing which a penalty equivalent to 50% of the monthly water bill will be levied on defaulters. While RWH has been mandatory in the city for several years, implementation has been extremely lax, followed by poor maintenance of existing structures.

DJB officials said that once the policy was implemented, a physical verification of structures would be carried out before the onset of monsoon each year. Action will be initiated if they are not properly maintained.

All PWD buildings will be made RWH compliant by April 2017. The urban development department will prepare a list of all government buildings, which do not have rainwater harvesting facilities. Such buildings will be served notices and they will be told to implement the new structural designs at the earliest. A meeting will be held with the Delhi Metro separately to work out details of RWH at its stations and platforms.

The latest policy was framed by the Delhi Dialogue Commission and DJB. Sources said DJB officials had spent considerable time in Chennai, which has successfully implemented rainwater harvesting. Water expert from Chennai SekarRaghvan helped DJB frame the policy and recommended structural designs.

"RWH is mandatory for all buildings in an area of 500sq m and above. There are around 10 areas where groundwater levels are reasonably high. Vetted by the Central Ground Water Authority, these areas will not be required to carry out RWH. These include Okhla, Siddharth Extension and Jahangirpuri. A central fund of Rs 2 crore has been allocated in this regard," said DDC vice-chairperson Ashish Khetan. He is also the head of the steering committee to monitor rainwater harvesting.

Delhi has a population of around 1.7 crore for whom DJB is able to supply 900 million gallons of water per day. An additional 200-250 MGD is supplied through groundwater sources. South and southwest Delhi are practically dry because of over-extraction of groundwater while levels are plummeting in other parts of the city.

Taking a leaf from Chennai's experience, Delhi is setting up three rain centres, along with NGOFORCE. These centres will provide information on all aspects of RWH, water recycling and water body revival, assist in implementing RWH and train masons and plumbers in the installation and maintenance of RWH structures. These will also work as a resource centres, which will maintain a database of all structures that are being made and publicise information related to RWH.

Additionally, DJB will set up 10 pilot projects across the city. The identified buildings are located in south and southwest Delhi. According to DJB officials, a detailed survey of each building is in progress and the policy will be implemented by June-end.