A taanka, also known as a tanka or kund, is a traditional

rainwater harvesting Rainwater harvesting (RWH) is the collection and storage of rain, rather than allowing it to run off. Rainwater is collected from a roof-like surface and redirected to a tank, cistern, deep pit (well, shaft, or borehole), aquifer, or a reservoir w ...

technique, common to the

Thar desert The Thar Desert, also known as the Great Indian Desert, is an arid region in the north-western part of the Indian subcontinent, Subcontinent that covers an area of and forms a natural boundary between India and Pakistan. It is the world's Li ...

region of

Rajasthan Rajasthan (; lit. 'Land of Kings') is a state in northern India. It covers or 10.4 per cent of India's total geographical area. It is the largest Indian state by area and the seventh largest by population. It is on India's northwestern si ...

, India. It is meant to provide

drinking water Drinking water is water that is used in drink or food preparation; potable water is water that is safe to be used as drinking water. The amount of drinking water required to maintain good health varies, and depends on physical activity level, a ...

and

water security Water security is the focused goal of water policy and water management. A society with a high level of water security makes the most of water's benefits for humans and ecosystems and limits the risk of destructive impacts associated with water. T ...

for a family or a small group of families. A taanka is composed of a covered, underground, impermeable

cistern A cistern (Middle English ', from Latin ', from ', "box", from Greek ', "basket") is a waterproof receptacle for holding liquids, usually water. Cisterns are often built to catch and store rainwater. Cisterns are distinguished from wells by t ...

on shallow ground for the collection of rainwater. The cistern is generally constructed out of stone or brick masonry, or concrete, with

lime mortar Lime mortar or torching is composed of lime and an aggregate such as sand, mixed with water. The ancient Egyptians were the first to use lime mortars, which they used to plaster their temples. In addition, the Egyptians also incorporated various ...

or cement plaster. Rainwater or surface run-off from rooftops, courtyards, or artificially prepared catchments (locally called ''agor'') flow into the tank through filtered inlets in the wall of the pit. The water stored saves people from the daily task of walking long distances to fetch water from sources which are often contaminated. The water in a taanka is usually only used for drinking. If in any year there was less than normal rainfall and household taankas do not get filled, water would instead be obtained from nearby wells and tanks to fill the taankas.

History

Taankas were usually constructed near religious centers and in villages for community usage due to the belief in the sanctity of water. This preservation technique is an ancient practice dating back to at least 1607 A.D. near Jodhpur. However, people now generally prefer to construct taankas locally in each hamlet and are owned and maintained by individual families. This shift is mainly due to dominant groups monopolizing or taking disproportionate shares of communal water, marginalizing the needs of poor and lower

caste Caste is a form of social stratification characterised by endogamy, hereditary transmission of a style of life which often includes an occupation, ritual status in a hierarchy, and customary social interaction and exclusion based on cultura ...

. Generally, community structures now fail through underinvestment leading to poor workmanship and aftercare. The technique was largely abandoned in the later 20th century as pipes lines or hand pumps were laid to transport water from Perennial Rajasthan Canal to their houses, though some houses still maintain the taankas since they do not like the taste of

tap water Tap water (also known as faucet water, running water, or municipal water) is water supplied through a tap, a water dispenser valve. In many countries, tap water usually has the quality of drinking water. Tap water is commonly used for drinking, ...

. When the region was faced with

drought A drought is defined as drier than normal conditions.Douville, H., K. Raghavan, J. Renwick, R.P. Allan, P.A. Arias, M. Barlow, R. Cerezo-Mota, A. Cherchi, T.Y. Gan, J. Gergis, D. Jiang, A. Khan, W. Pokam Mba, D. Rosenfeld, J. Tierney, an ...

-like situations, inadequate supplies of piped water on the account of growing population, and depleted or contaminated ground water, this traditional method was revived, along with other traditional rainwater harvesting structures like, ''Naadi'', a village pond and ''Beri'', a small rainwater-collecting wells, especially for supplying drinking water. Though originally found in the desert towns, the system has since gained immense popularity in rural areas. In

Phalodi Phalodi is a town and a municipality in Jodhpur district in the Indian state of Rajasthan. It is the headquarters for Phalodi tehsil. Phalodi is also called the "salt city" due to the salt industry in Rin. Phalodi is in the buffer zone of Thar ...

, Barmer and

Balotra Balotra is a city in Barmer district of Rajasthan state in India. It is about from Barmer city. Geography Balotra is located at . It has an average elevation of 106 metres (347 feet). Demographics India census, Balotra had a ...

region, rural taankas were found that were 6.1 meters (20 ft) deep, 4.27 meters (14 ft) long and 2.44 meters (8 ft) wide. This technique of harvesting rainwater was perfected to a fine art in the arid regions of western

. Such water harvesting structures have also been reported being built in other arid

developing countries A developing country is a sovereign state with a lesser developed industrial base and a lower Human Development Index (HDI) relative to other countries. However, this definition is not universally agreed upon. There is also no clear agreem ...

such as

Botswana Botswana (, ), officially the Republic of Botswana ( tn, Lefatshe la Botswana, label=Setswana, ), is a landlocked country in Southern Africa. Botswana is topographically flat, with approximately 70 percent of its territory being the Kalahar ...

Ghana Ghana (; tw, Gaana, ee, Gana), officially the Republic of Ghana, is a country in West Africa. It abuts the Gulf of Guinea and the Atlantic Ocean to the south, sharing borders with Ivory Coast in the west, Burkina Faso in the north, and To ...

Kenya ) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , ...

Yemen Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the Saudi Arabia–Yemen border, north and ...

Sri Lanka Sri Lanka (, ; si, ශ්‍රී ලංකා, Śrī Laṅkā, translit-std=ISO (); ta, இலங்கை, Ilaṅkai, translit-std=ISO ()), formerly known as Ceylon and officially the Democratic Socialist Republic of Sri Lanka, is an ...

Thailand Thailand ( ), historically known as Siam () and officially the Kingdom of Thailand, is a country in Southeast Asia, located at the centre of the Indochinese Peninsula, spanning , with a population of almost 70 million. The country is bo ...

, and

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

.Mahnot, S. C., and P. K. Singh. "Arid Zone Water Harvesting." ''Water Harvesting and Management'', Swiss Agency for Development and Cooperation, 2003.

Bikaner Bikaner () is a city in the northwest of the state of Rajasthan, India. It is located northwest of the state capital, Jaipur. Bikaner city is the administrative headquarters of Bikaner District and Bikaner division. Formerly the capital of ...

was founded by

Rao Bika Rao Bika Rathore (5 August 1438 – 17 June 1504), was the founder of the Kingdom of Bikaner in present-day Rajasthan. He was a scion of the Rathore clan of Rajputs. He was a son of Rao Jodha, founder of the kingdom of Marwar. Establishment ...

in 1488 AD. The choice of Bikaner as an urban center seems to have been strongly influence by the availability of tracts of mudiya kanker, also known as murrum (मूरड़), a particular set of gravel and dirt which compacts easily when mike with water and possesses excellent run off characteristics. This facilitated rainwater harvesting through an elaborate network of taankas.''Water Harvesting Systems : Traditional Systems''. http://www.rainwaterharvesting.org/Rural/Traditional2.htm#tank. Accessed 30 Dec. 2019.

Construction

Traditional family-managed taankas are constructed by digging a hole of 3 to 4.25 meter diameter in the ground and plastering it with lime mortar cement about 6 mm thick, followed by a cement plaster of about 3 mm thickness. Most modern taankas have a capacity of around 21,000 liters but larger ones can be constructed where resources are available. Commonly, the catchment area, known as an agor, is a concave cemented funnel-like slope directing water into a collection pit that reduces the sediment load of water before it enters the underground cistern via a suitable mesh supported by bars in an angle iron frame to filter out other large debris. The micro-catchment avoids seepage and prevents erosion, and is fenced to restrict animal entry. The bottom of the cistern is also concave facilitating extraction of the maximum amount of water from the taanka. The cistern has a top cover to prevent evaporation and pollution of stored water by foreign matter. A

galvanised Galvanization or galvanizing ( also spelled galvanisation or galvanising) is the process of applying a protective zinc coating to steel or iron, to prevent rusting. The most common method is hot-dip galvanizing, in which the parts are submerged ...

iron cover is built into the cover to facilitate withdrawal of water. Taanka covers are ventilated, helping to prevent bad odor in the stored water. Outlets are provided to allow excess water falling during the

monsoon A monsoon () is traditionally a seasonal reversing wind accompanied by corresponding changes in precipitation but is now used to describe seasonal changes in atmospheric circulation and precipitation associated with annual latitudinal oscil ...

to escape. Taankas are often beautifully decorated with tiles, which also keep the water cool.

Usage and Maintenance

Taanka require cleaning at least once a year, typically before the onset of the monsoon. This includes desilting the taanka cistern, sweeping the micro-catchment, and painting inlets and the outlet to keep the system in good working condition. Periodic dosing with

oxidizing agents An oxidizing agent (also known as an oxidant, oxidizer, electron recipient, or electron acceptor) is a substance in a redox chemical reaction that gains or " accepts"/"receives" an electron from a (called the , , or ). In other words, an oxid ...

, such as

potassium permanganate Potassium permanganate is an inorganic compound with the chemical formula KMnO4. It is a purplish-black crystalline salt, that dissolves in water as K+ and , an intensely pink to purple solution. Potassium permanganate is widely used in the c ...

, helps prevent the growth of microscopic organisms and the consequent development of bad taste, odor and color in the water. Alum additions also help to settle suspended matter. At least a few centimetres of water should always be maintained in the taanka to ensure that the cistern walls remain moist, avoiding the development of cracks and other physical defects. If well maintained, a taanka has a service life of at least for 30 years.Vangani, N. S., et al. ''Tanka—A Reliable System of Rainwater Harvesting in the Indian Desert''. Central Arid Zone Research Institute, 1988, http://www.cazri.res.in/publications/KrishiKosh/60-(TANKA-A%20RELIABLE%20SYSTEM%20OF%20RAINWATER%20).pdf

Usage in Present Day

In towns around Bikaner, there was an abundance of tanks. The most important ones being at

Kolayat Kolayat is a town in the Bikaner district of the Indian state of Rajasthan. It is also the headquarters of the eponymous tehsil. The town is from Bikaner on NH 15, National Highway 15 to Jaisalmer. History Kolayat is an historical centre of p ...

with a catchment area of , Gajner , and Ganga sarovar with . The water needs of the town were met by the innumerable tanks in and around Bikaner, together with the wells and taankas that each house traditionally built for harvesting rainwater from the roof tops. The water from the taankas was used only for drinking purposes. If in any year there was less than normal rainfall and the taankas did not get filled, water from proximal wells and tanks would be obtained to fill the household taankas. In this way, the people of Bikaner were able to meet their water requirements.

References

{{Reflist *''Traditional Water Resource Management Through Innovative Techniques'', Rajendra Kumar, Jodhpur 2009 * Anupam Mishra (1995), "Rajasthan ki rajat bunde", Published by Gandhi Shanti Prathisthan, New Delhi. *Pravesh Kumar (2007), "Importance of water harvesting in Rajasthan", Water Wheel, August 2007, P 5-7. *D.C. Ojha (1997), "Thar Desert: An Overview of Desertification", ENVIS Centre on Desertification, Central Arid Zone Research Institute. *Bharat Jhunjhunwala (2005), ''Traditional Agricultural and water technologies of the Thar'', Kalpaz Publications *Madhukar Gupta (2002), "Drought Management in Rajasthan", Report of District Collector & Magistrate, Nagaur, Rajasthan, India.

External links

Thirsty Communities - Harvesting the Rains in Rajasthan
at

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