Rainwater harvesting has a long history in India and provides many benefits. It reduces costs, conserves water resources, and is a simple technique appropriate for both rural and urban areas. Traditional methods were widely used across India and involved collecting rainwater and storing it for multiple uses. Many regions developed innovative indigenous solutions, such as kunds in Rajasthan and bamboo drip irrigation in Meghalaya. While rainwater harvesting declined in some places, its importance is now being recognized again and modern techniques are reviving traditional methods.

1. Rainwater Harvesting

2. Why?EconomicsReduces water bills

3. Reduced water demand - water supply utility saves money on treatment and pumping

4. Reduces cost of infrastructure necessary for water supplyEnvironmentEnergy saved – no pumping of water to our homes

5. If water is hard, adding soft rainwater improves water quality

6. Improves groundwater situation

7. Reduces demand for water at city / village levelOtherSimple, cost-effective, easy to construct and maintain

8. Viable in urban and rural areas, slums, low income housing, apartments..

9. Can offset the need for multipurpose river projectsHow?The concept is simpleCollect

10. Store and use

11. RechargeNot new to IndiaRainwater storage reservoir at Dholavira (Rann of Kutch) – Harappan civilization (2500-1900 BC)

12. Mountainous rain-shadow regions like Spiti valleyFlood plains to check floods during monsoonsThe Deccan plateau which has only monsoon fed(no perennial) riversTraditional rainwater harvesting systemsWidely prevalent in all parts of India

13. Desert and arid region , Rajasthan, Rann of Kutch etc.Traditional rainwater harvesting systemsMountainous regions with heavy rainfall to check erosion and to provide water in non-rainy months since water distribution systems are not easy to installWidely prevalent in all parts of India

14. Centuries old ‘Kul irrigation’ in the Western Himalayan mountainous rain-shadow regions like Spiti valleyGlacier melt is diverted into the head of a ‘kul’ or a diversion channelThese ‘kuls’ channel the water over many kilometersThey lead into a tank in the village from which water flow is regulated

15. FieldsFieldsInundation channelBengal Flood plainsFloodwater entered the fields through the inundation canals

16. The waters brought in rich silt and fish

17. The fish fed on mosquito larva and helped check malaria in this region.EmbankmentRiverKana/ Nadi

18. Khadins of Jaisalmer(harvesting structures for agricultural fields) Designed by the Paliwal Brahmins of Jaisalmer, in 15th century

19. Similar system also practised in Ur (Iraq), the Negev desert, and in south west Colorado

20. An embankment prevents water from flowing away. Collected water seeps into the soil. This water saturates land, which is then used for growing crops

21. Johads of Rajasthan(provide water for domestic use) Earthen or masonry rainwater harvesting structure, for providing water for domestic use to the communities.Photo by L R Burdak

22. Johads of Rajasthan(provide water for domestic use)Photo by Farhad Contractor, taken in Alwar district of RajasthanRead about revival of Johads in ‘Reviving India’s water harvesting systems’

23. Tankas of Bikaner, Barmer, Phalodi - RajasthanPipes from the rooftop lead rainwater into the tanka catchmentNote the slope provided for the rainwater (palar pani) to flow into the tanka

24. Tankas for storing drinking waterThar desert region of Rajasthan (Barmer, Bikaner, Pallodi)Unique underground structures of various shapes and sizes to collect rain water for drinking purposes

25. Sometimes used to store drinking water brought from far off wells in case the rainwater gets exhausted

26. Constructed in court yards or in front of houses and temples,

27. Built both for individual households as well as for village communitiesTankas of Bikaner, Barmer, Phalodi - RajasthanMain source of drinking water in these areas

28. People protect and maintain them

29. Just before the on-set of the monsoon, the catchment area of the Tanka is cleaned up to remove all possible pollutants

30. Human activity and grazing of cattle in the area is prohibited

31. First spell of rain not collected Tankas of Bikaner, Barmer, Phalodi - Rajasthan Provide enough drinking water to tide over the water scarcity during the summer months even though average annual rainfall is as less as 200 mm to 300 mm. In many cases the stored water lasts for the whole year.

32. These simple traditional water harvesting structures are useful even during years of below-normal rainfall.Rainwater harvesting in Rajasthan todayRajasthan Canal (Indira Gandhi Nahar Project) brings water (for agriculture and domestic use) from the Sutlej and Beas riversRainwater harvesting was on declineBeing revived in many parts of Rajasthan: traditional methods with some improvisations

33. Deccan PlateauThenWater harvested in a system of tanks that were fed by seasonal streamsTanks recharged groundwaterDeccan PlateauNow Tanks neglected

34. Many regions facing water scarcity

35. Importance of rainwater harvesting being realized

36. Rooftop rainwater harvesting getting a boostNo perennial rivers

37. Rainwater harvesting in the North Eastern statesMountainous regions with heavy rainfallUneven distribution of populationAbundant water resources but not tapped due to rugged terrainFace water scarcity in areas of high population density

38. Bamboo drip irrigation in Meghalaya

39. Bamboo drip irrigation inMeghalaya200-year-old system

40. Used by tribal farmers of Khasi and Jaintia hills

41. Bamboos divert water from perennial springs on hilltops to the lower reaches by gravity

42. Used to irrigate the betel leaf or black pepper crops

43. 18-20 litres of water entering the bamboo pipe system per minute gets transported over several hundred meters and finally gets reduced to 20-80 drops per minute at the site of the plant. Attempts made to introduce modern pipe systems but farmers prefer to use their indigenous form of irrigation. Kunds/Kundis A kund or kundi looks like an upturned cup nestling in a saucer. These structures harvest rainwater for drinking, and dot the sandier tracts of the Thar Desert in western Rajasthan and some areas in Gujarat. Essentially a circular underground well, kunds have a saucer-shaped catchment area that gently slopes towards the centre where the well is situated. A wire mesh across water-inlets prevents debris from falling into the well-pit.

44. Kunds/ Kundis The sides of the well-pit are covered with (disinfectant) lime and ash. Most pits have a dome-shaped cover, or at least a lid, to protect the water. If need be, water can be drawn out with a bucket. The depth and diameter of kunds depend on their use (drinking, or domestic water requirements). They can be owned by only those with money to invest and land to construct it. Thus for the poor, large public kunds have to be built.

45. Rainwater harvesting todayCollection (Catchment)Flat / sloping roofs Transportation: Downtake pipesLeaf and grit filter, First flush deviceStorage in tanksRecharge into open wells / borewells / percolation pits / trenches

46. Case studies of interest - LegislationTamil NaduRainwater harvesting made mandatory for all the buildings in the state

47. If the rain water harvesting structure is not provided as required, an authorized person can implement a rain water harvesting structure and the cost is recovered along with property tax".

48. Citizens are also warned about disconnection of water supply connection if rainwater harvesting structures are not provided. Case studies of interest - ImplementationKarnatakaGendathur (Karnataka)- a remote village in Mysore district

49. The first village to have installed a maximum number of rainwater harvesting systems.

50. Each of the 200 houses have a rooftop rainwater harvesting system

51. TheMysore Zilla Panchayat, an NGO (MYRADA) and the villagers worked together

52. The villagers contributed20%of the project cost.

53. The villagers ofGendathur use rainwater for all their everyday needs; they even use it for drinking and cooking. LehLadakhChewangNorphel, 62, of Leh, Ladakh.

54. In Ladakh, the annual average rainfall is 50 mm. The only source of water are glaciers, which melt in late summer. Water shortage felt at the start of the cropping season in early summer (May to June)

55. Taps left open in winter, so that water does not freeze in the pipelines (Water wasted in winter)

56. Norphel builds artificial glaciers by channelising glacier water into depressions lying in the shadow area of a mountain, hidden from sunlight.

57. He places half-inch-wide iron pipes at the edge of the depression. As the water keeps collecting in the pipes, it freezes. As more water seeps in, it pushes out the frozen blocks, and in turn, itself gets frozen. This keeps happening in a continuous cycle, and these frozen blocks create a clean, artificial glacier.

58. Norphel has made four such glaciers.Maharashtra - PhadThe community-managed phad irrigation system, prevalent in northwestern Maharashtra, probably came into existence some 300-400 years ago. The system operated on three rivers in the Tapi basin - Panjhra, Mosam and Aram - in Dhule and Nasik districts (still in use in some places here).

59. The size of a phad can vary from 10-200 ha, the average being 100-125 ha. Every year, the village decides which phads to use and which to leave fallow. Only one type of crop is allowed in one phad. Generally, sugarcane is grown in one or two phads; seasonal crops are grown in the others. This ensures a healthy crop rotation system that maintains soil fertility, and reduces the danger of waterlogging and salinity. The phad system has given rise to a unique social system to manage water use.

60. Karnataka - Kere Tanks, called kere in Kannada, were the predominant traditional method of irrigation in the Central Karnataka Plateau, and were fed either by channels branching off from anicuts (check dams) built across streams, or by streams in valleys. The outflow of one tank supplied the next all the way down the course of the stream; the tanks were built in a series, usually situated a few kilometres apart. This ensured: a) no wastage through overflow, andb) the seepage of a tank higher up in the series would be collected in the next lower one.

61. Katas / Mundas / BandhasKatas / Mundas / BandhasThe katas, mundas and bandhas were the main irrigation sources in the ancient tribal kingdom of the Gonds (now in Orissa and Madhya Pradesh). Most of these katas were built by the village headmen known as gountias, who in turn, received the land from the Gond kings. Land here is classified into four groups on the basis of its topography: aat, (highland); mal (sloped land); berna (medium land); and bahal (low land). This classification helps to select

62. A kata is constructed north to south, or east to west, of avillage. A strong earthen embankment, curved at either end, is built across a drainage line to hold up an irregularly-shaped sheet of water. The undulations of the country usually determine its shape as that of a long isosceles triangle, of which the dam forms the base. It commands a valley, the bottom of which is the bahal land and the sides are the mal terrace. As a rule, there is a cut high up on the slope near one end of the embankment from where water is led either by a small channel or tal, or from field to field along terraces, going lower down to the fields.

63. Want to play

64. Divide the class into 5 teamsTeam A selects 2 persons who will pick the clue and draw it out on the board for the other team members to guess. If the guessers get the right answer in 30 secs, they get 5 pointsIf the guessers get the right answer in 60 secs, they get 3 points Otherwise The chance then goes to Team B and so on.RulesNo mouthing of wordsNo names or numbers to be writtenNo actions

65. Turn off the projector now, so that the whole class cannot see the clues. The 2 representatives of Team Acan come up to the computer and see the clue.Ready?

66. Round 1Team A – KhadinTeam B – JohadTeam C – TankaTeam D – KulTeam E – Inundation channel

67. Round 2Team A – DholaviraTeam B – Spiti valleyTeam C – Rann of KutchTeam D – Deccan PlateauTeam E – Jaisalmer

68. Round 3Team A – TharTeam B – North East IndiaTeam C – Bamboo drip irrigationTeam D – Indira Gandhi CanalTeam E – Gendathur

69. Round 4Team A – collectionTeam B – storageTeam C – rechargeTeam D – filterTeam E – pipelines