Rainwater Harvesting Std X CBSE As per NCERT

Rainwater Harvesting Std X – CBSE As per NCERT Geography textbook Contemporary India II

Why? Economics S Reduces water bills S Reduced water demand - water supply utility saves money on treatment and pumping S Reduces cost of infrastructure necessary for water supply Environment S S Energy saved – no pumping of water to our homes If water is hard, adding soft rainwater improves water quality Improves groundwater situation Reduces demand for water at city/village level Other S Simple, cost-effective, easy to construct and maintain S Viable in urban and rural areas, slums, low income housing, apartments S Can offset the need for multipurpose river projects

How? The concept is simple S Collect S Store and use S Recharge

Not new to India Source: http: //blog. shunya. net/shunyas_blog/2008/08/dholavira-a-har. html Rainwater storage reservoir at Dholavira (Rann of Kutch) – Harappan civilization (2500 -1900 BC)

Traditional rainwater harvesting systems Mountainous rain-shadow regions like Spiti valley Flood plains to check floods during monsoons The Deccan plateau which has only monsoon fed (no perennial) rivers Widely prevalent in all parts of India

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

Centuries old ‘Kul irrigation’ in the Western Himalayan mountainous rain-shadow regions like Spiti valley Glacier melt is diverted into the head of a ‘kul’ or a diversion channel These ‘kuls’ channel the water over many kilometers They lead into a tank in the village from which water flow is regulated Source: http: //www. rainwaterharvesting. org/methods/traditional/kuls. htm Accessed November 2008

Inundation channel Bengal Flood plains SFloodwater entered the fields through the inundation canals S The waters brought in rich silt and fish Em ba nk m en t S The fish fed on mosquito larva and helped check malaria in this region. Ri r ve Fields Kan a/ N a Fields di

Khadins of Jaisalmer (harvesting structures for agricultural fields) S Designed by the Paliwal Brahmins of Jaisalmer, in 15 th century S Similar system also practised in Ur (Iraq), the Negev desert, and in south west Colorado S An embankment prevents water from flowing away. Collected water seeps into the soil. This water saturates land, which is then used for growing crops

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

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

Tankas of Bikaner, Barmer, Phalodi - Rajasthan Pipes from the rooftop lead rainwater into the tanka catchment Note the slope provided for the rainwater (palar pani) to flow into the tanka

Tankas for storing drinking water Thar desert region of Rajasthan (Barmer, Bikaner, Pallodi) S Unique underground structures of various shapes and sizes to collect rain water for drinking purposes S Sometimes used to store drinking water brought from far off wells in case the rainwater gets exhausted S Constructed in court yards or in front of houses and temples, S Built both for individual households as well as for village communities

Tankas of Bikaner, Barmer, Phalodi - Rajasthan S Main source of drinking water in these areas S People protect and maintain them S Just before the on-set of the monsoon, the catchment area of the Tanka is cleaned up to remove all possible pollutants S Human activity and grazing of cattle in the area is prohibited S First spell of rain not collected

Tankas of Bikaner, Barmer, Phalodi - Rajasthan S 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. S In many cases the stored water lasts for the whole year. S These simple traditional water harvesting structures are useful even during years of below-normal rainfall.

http: //twofloatingweeds. blogspot. com http: //pashunz. blogspot. com/2006_12_01_archive. html Rainwater harvesting in Rajasthan today • Rajasthan Canal (Indira Gandhi Nahar Project) brings water (for agriculture and domestic use) from the Sutlej and Beas rivers • Rainwater harvesting was on decline • Being revived in many parts of Rajasthan: traditional methods with some improvisations For more information, check out http: //www. rainwaterharvesting. org/Rural/Improvised. htm 000

Deccan Plateau Then • Water harvested in a system of tanks that were fed by seasonal streams • Tanks recharged groundwater Deccan Plateau Now • Tanks neglected • Many regions facing water scarcity • Importance of rainwater harvesting being realized • Rooftop rainwater harvesting getting a boost No perennial rivers

Rainwater harvesting in the North Eastern states Mountainous regions with heavy rainfall • Uneven distribution of population • Abundant water resources but not tapped due to rugged terrain • Face water scarcity in areas of high population density http: //media-2. web. britannica. com

Bamboo drip irrigation in Meghalaya

Bamboo drip irrigation in Meghalaya S 200 -year-old system S Used by tribal farmers of Khasi and Jaintia hills S Bamboos divert water from perennial springs on hilltops to the lower reaches by gravity S Used to irrigate the betel leaf or black pepper crops S 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. S Attempts made to introduce modern pipe systems but farmers prefer to use their indigenous form of irrigation.

For more information on Rain Water Harvesting Systems in different regions S Check out http: //www. rainwaterharvesting. org/eco-region. htm S Read the book ‘Dying wisdom’ published by the Centre for Science and Environment (CSE) S Brief notes on some traditional water harvesting structures are available at ‘Traditional Water Harvesting Structures’ information sheet on www. indiawaterportal. org

Rainwater harvesting today Collection (Catchment) Flat / sloping roofs Transportation: Downtake pipes Leaf and grit filter, First flush device Storage in tanks Recharge into open wells / borewells / percolation pits / trenches

Case studies of interest - Legislation Tamil Nadu S Rainwater harvesting made mandatory for all the buildings in the state S 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". S Citizens are also warned about disconnection of water supply connection if rainwater harvesting structures are not provided. To learn more about policies and legislation (India and abroad), check out http: //www. rainwaterharvesting. org/Policy/Legislation. htm

Case studies of interest - Implementation Karnataka S Gendathur (Karnataka) - a remote village in Mysore district S The first village to have installed a maximum number of rainwater harvesting systems. S Each of the 200 houses have a rooftop rainwater harvesting system S The Mysore Zilla Panchayat, an NGO (MYRADA) and the villagers worked together S The villagers contributed 20% of the project cost. S The villagers of Gendathur use rainwater for all their everyday needs; they even use it for drinking and cooking.

Some people S Chewang Norphel, 62, of Leh, Ladakh. S In Ladakh, the annual average rainfall is 50 mm. The only source of water are glaciers, which melt in late summer. S Water shortage felt at the start of the cropping season in early summer (May to June) S Taps left open in winter, so that water does not freeze in the pipelines (Water wasted in winter) S Norphel builds artificial glaciers by channelising glacier water into depressions lying in the shadow area of a mountain, hidden from sunlight. S 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. S Norphel has made four such glaciers. To learn more about people who are making a difference, check out http: //www. rainwaterharvesting. org/People. htm

Want to play

• • Divide the class into 5 teams Team 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 points If the guessers get the right answer in 60 secs, they get 3 points Otherwise The chance then goes to Team B and so on. Rules • • • No mouthing of words No names or numbers to be written No actions

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