Rainwater harvesting in Chandigarh_Architect Surinder Bahga_August 19, 2015

Best practices in rainwater harvesting from across the world and how Chandigarh can benefit from this knowledge. A presentation by Architect Surinder Bahga at an event on water conservation organised by PHD Chamber of Commerce on August 19, 2015

1. RAIN WATER HARVESTING SYSTEM Ar SURINDER BAHGA SAAKAAR FOUNDATION Chandigarh

2. Water, simply put, makes the existence of the human race on this planet possible.  With few exceptions, water has always been a natural resource that people take for granted .  WATER AND HUMAN EXISTENCE

3. The World Bank reports that, 80 Countries now have water shortages and 2 billion people lack access to clean water. In the last century, the human population has increased from 1.7 billion to 6.6 billion people , and total amount of portable water decreased . The UNEP* also reports that 1.2 billion people are being affected by polluted water , and that dirty water contributes to 15 million child deaths every year . *UNEP- UNITED NATION ENVIRONMENTAL PROGRAMME IS THE AVAILABILITY OF WATER ADEQUATE?

4. WE NEED TO SAVE WATER FOR HUMANITY STRATEGIES OF WATER CONSERVATION Any beneficial reduction in water loss, use and waste of resources . Avoiding any damage to water quality . Improving  Water Management Practices that reduce or enhance the beneficial use of water.

5. WATER MANAGEMENT PRACTICES REUSE of gray water. RECYCLING of wastewater through purification at a water treatment plant.  RAINWATER HARVESTING

6. RAINWATER HARVESTING Rainwater harvesting is a technique used for collecting, storing, and using rainwater  for landscape irrigation and other uses. The rainwater is collected from various hard surfaces such as roof tops and/or other types of manmade above ground hard surfaces.

7. HISTORIC PERSPECTIVE The concept of rainwater harvesting began around the 300BC, when the farming communities in  Balochistan  (now located in Pakistan, Afghanistan and Iran), and  Kutch, India , used rainwater harvesting for irrigation. Rainwater harvesting was done in the Indian states of  Madhya Pradesh, Maharashtra, and Rajasthan  in the olden days.  Ratanpur , in the state of Chhattisgarh, had around 150 ponds .

8. PRACTICE IN INDIA STEP WELLS The builders dug deep trenches into the earth for dependable, year-round groundwater . They created stairs leading down to the water. Step wells also served a leisure purpose , as well as providing water. Step wells also served as a place for social gatherings and religious ceremonies. Adalaj Wav Step Well Drawing

9. Chand Baori  in  Abhaneri,   Rajasthan

10. Stepped Well, Hampi , Karnataka

11. Agrasen Ki Baoli , New Delhi

12. Rani ki Vav , Patan , Gujarat

13. Rani ki Vav , Patan , Gujarat

14. Richard Cox is a senior lecturer at Cardiff School of Art and Design UK, studied 300 step-wells of India in 20 years . RICHARD COX – A RESEARCHER OF STEPWELLS

15. RAJENDRA SINGH - CHOSEN FOR 2015 STOCKHOLM AWARD FOR WATER CONSERVATION In about 20 years since Singh has begun working, 8,600 rain water storage tanks and other structures to collect water have been built. Water had been brought back to around 1,000 villages across the state, the organisation claimed.

16. RAINWATER HARVESTING SYSTEM - CHENNAI Chennai government made the installation of RWHS compulsory as per the by-laws. Chennai saw a 50% rise in water level in 5 years and improve water quality also .

17. PRACTICES AROUND THE WORLD MEXICO Lomnitz is the director of Isla Urbana, explains that, rainwater harvesting is a natural fit in Mexico City, since over a million homes already have tanks, or cisterns, for storing water from either the intermittent city water system or delivery trucks.

18. People don't have to buy a cistern because these are already part of their houses. Therefore, the system is quick and easy to install.

19. The roofs are tilted and diverted towards a 1,000 cubic metre basement tank from where the water is used for toilet flushing and cooling the building JAPAN

20. From 1985, the country constructed six million jars to harvest the rain for drinking purpose. In a year, there are 150 days during which water from jar has to be used. Thai Jar THAILAND

21. ISRAEL The first rainwater catchment system was installed at an elementary school in Lod , Israel. RWHS are being installed in local schools for the purpose of educating school children since then. Roof collection system – 8500 litre reservoir: 10 toilets (1/2 of school bathrooms).

22. NEED OF RWHS IN CHANDIGARH Chandigarh is a fast growing city. Growth Rate has increased by 28% in the past decade Estimated by 2025, the water demand will be 800 MLD that is about 58 % higher over the 2011 demand of 494.25 MLD.

23. Ground water level has declined swiftly in last decade. The data collected by the CGW, Chandigarh shows a gradual decrease in the total decreased Ground Water Resources (3.636%) *CGW – CENTRALGROUND WATER BOARD * ham = Hectare metre STATUS OF GROUND WATER LEVEL

24. DECLINE GRAPH

25. The rainwater harvesting potential of Chandigarh is 50%, of the average water storage Annual rainfall is 1061 millimetres. Therefore, storing and recharging rainwater will go a long way in contributing towards sustainability of water supply. BENEFITS CHANDIGARH CAN GAIN THROUGH RWHS

26. HOW TO CONSTRUCT A RWHS

27. RECHARGE PIT LAYOUT

28. RWH THORUGH STORM WATER Rainwater harvesting potential: Rooftop- 80% Roads- 50% Green areas- 20% The drainage wells or traps for storm water must be covered to ensure less pollution in the water. DETAIL OF ROAD SIDE STROM WATER TRAP

29. RWH ON CITY LEVEL Initial Plan of Chandigarh by Albert Mayer Included Two Leisure Valleys LEISURE VALLEY LEISURE VALLEY

30. Later on Le Corbusier Built One Leisure Valley

31. Now as Chandigarh has developed on its periphery, two more leisure valleys can be constructed to reserve more water through CHECK DAM.

32. CHECK – DAM SYSTEM

33. A CONCEPTUAL SKETCH GIVEN BY RAJENDRA SINGH ON VISIT IN CHANDIGARH RWH system should be improved by Check –Dam system. He advised to provide Reservoir in each sector which store water hence adequate storage for people . DETAIL B

34. DETAIL:

35. The New Lake at Sector 42, Chandigarh Spread over three acres, is fed by two tube wells. Instead if the rain water of the surrounding sectors can be trapped and supplied to it, a lot of ground water can be saved. SECTOR - 42 LAKE VIEW

36. EACH SECTOR DESIGN The Periphery of a typical sector measures 1200 m x 800 m. Storm water drains run on either three or all four sides of the sector. Recharge structures can be built at intervals of 50 m. STORM WATER TRAPS AT PERIPHERIAL ROADS

37. LAYOUT OF SECTOR 20

38. RWH ON BUILDING LEVEL COMMERCIAL AREAS Also rooftops of the commercial areas may harvest a good amount of water . Large spaces are designed in commercial areas used for Parking . If covered with PERVIOUS CEMENT CONCRETE they can absorb a large amount of water

39. RESIDENTIAL AREAS RWH ON BUILDING LEVEL Processes of rain water harvesting: Cascade capture Ground water recharge shaft Recharge through soak pit/hand pump/ bore well/ settlement tank Recharge through trench Roof water harvesting

40. RECHARGE THROUGH SOAK PIT/HAND PUMP/ BORE WELL/ SETTLEMENT TANK SETTLEMENT TANK SETTLEMENT TANK

41. ROOF WATER HARVESTING Making Terrace Garden Supporting roof structure Waterproof and root repellent membrane(s) Insulation TYPICAL ROOF SECTION FOR HARVESTING

42. PROJECTS BY:

43. SITE PLAN OF BUILDING – DESIGN OF RWH SYSTEM SBI BANK, SECTOR - 17, CHANDIGARH

44. DETAIL OF RECHARGE WELL

45. MARRIED ACCOMODATION, JAIPUR, RAJASTHAN

46. RAIN WATER HARVESTING LAYOUT OF THE HOUSING

47. DETAIL OF RECHARGE WELL

48. Malkiet Singh House, Chandigarh

49. Vipin Pubby House, Chandigarh

50. Red Cross, Chandigarh

51. CONCLUSION With the decreasing availability of water, RAIN WATER HARVESTING is one of the best options of conserving water. RHW should be made mandatory through Bye-laws by Government . This Recyclable process sustained the Bio-diversity hence makes us SMART and GREEN

52. THANK YOU