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?

5. 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.

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

7. 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.

8. 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.

9. 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

10. Chand Baori in Abhaneri, Rajasthan

11. Stepped Well, Hampi, Karnataka

12. Agrasen Ki Baoli, New Delhi

13. Rani ki Vav, Patan, Gujarat

14. Rani ki Vav, Patan, Gujarat

15.  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

16. 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.

17. 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.

18. 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.

19. 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.

20. 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

21. 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

22. 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).

23. 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.

24.  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

25. DECLINE GRAPH

26.  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

28. HOW TO CONSTRUCT A RWHS

29. RECHARGE PIT LAYOUT

30. 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

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

32. Later on Le Corbusier Built One Leisure Valley

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

34. CHECK – DAM SYSTEM

35. 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

36. DETAIL:

37. 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

38. 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

39. LAYOUT OF SECTOR 20

40. 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

41. 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

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

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

44. PROJECTS
BY:

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

46. DETAIL OF RECHARGE WELL

47. MARRIED ACCOMODATION, JAIPUR,
RAJASTHAN

48. RAIN WATER HARVESTING LAYOUT OF THE HOUSING

49. DETAIL OF RECHARGE WELL

50. Malkiet Singh House, Chandigarh

51. Vipin Pubby House, Chandigarh

52. Red Cross, Chandigarh

53. 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

54. THANK YOU