Introduction:

• In India, a warming climate is drying up lakes and rivers, while rapid urbanization and water pollution are putting enormous pressure on the quantity and quality of surface and ground water.
• The country’s fragile agricultural system still depends primarily on rainfall and a bad monsoon season can wreck havoc on the national economy.
• Statistics reveal that the per capita availability of water in India has fallen from 6,042 cubic metre in 1947 to about 1,545 cubic metre in 2011.
•  History tells us that both floods and droughts were regular occurrence in ancient India.
•  Perhaps this is why every region in the country has its own traditional water harvesting techniques that reflect the geographical peculiarities and cultural uniqueness of the regions.
• The basic concept underlying all these techniques is that rain should be harvested whenever and wherever it falls.
• Archaeological evidence shows that the practice of water conservation is deep rooted in the science of ancient India.
• The settlement of Dholavira, laid out on a slope between two storm water channels, is a great example of water engineering.
• Chola King Karikala built the Grand Anicut or Kallanai across the river Cauvery to divert water for irrigation (it is still functional) while King Bhoja of Bhopal built the largest artificial lake in India.
• With rainfall patterns changing almost every year, the Indian government has started looking at means to revive the traditional systems of water harvesting in the country.
• Given that these methods are simple and eco-friendly for the most part, they are not just highly effective for the people who rely on them but they are also good for the environment

Some traditional water conservation practices:

•  Jhalara : Jhalaras are typically rectangular-shaped stepwells that have tiered steps on three or four sides. These stepwells collect the subterranean   seepage of an upstream  reservoir or a lake.The city of Jodhpur has eight jhalaras, the oldest being the Mahamandir Jhalara that dates back to 1660 AD.
•  Talab /Bandhi : Talabs are reservoirs that store water for household consumption and drinking purposes. They may be natural, such as the pokhariyan   ponds at Tikamgarh in the Bundelkhand region or man made, such as the lakes of Udaipur.
• Bawari : Bawaris are unique stepwells that were once a part of the ancient networks of water storage in the cities of Rajasthan. To minimise water loss through evaporation, a series of layered steps were built around the reservoirs to narrow and deepen the wells.
• Taanka : A Taanka is a cylindrical paved underground pit into which rainwater from rooftops, courtyards or artificially prepared catchments flows. Once completely filled, the water stored in a taanka can last throughout the dry season and is sufficient for a family of 5-6 members.
• Ahar Pynes : Ahar Pynes are traditional floodwater harvesting systems indigenous to South Bihar. Pynes are artificial rivulets led off from rivers to collect water in the ahars for irrigation in the dry months.
• Johads : Constructed in an area with naturally high elevation on three sides, a storage pit is made by excavating the area, and excavated soil is used to create a wall on the fourth side. This prevents structural damage to the water pits that are also called madakas in Karnataka and pemghara in Odisha.
• Panam Keni : The Kuruma tribe (a native tribe of Wayanad) uses a special type of well, called the panam keni, to store water. Wooden cylinders are made by soaking the stems of toddy palms in water for a long time so that the core rots away until only the hard outer layer remains and then it is used to store the water.
• Khadin : The main feature of a khadin, also called dhora, is a long earthen embankment that is built across the hill slopes of gravelly uplands. Sluices and spillways allow the excess water to drain off and the water-saturated land is then used for crop production
• Kund : A kund is a saucer-shaped catchment area that gently slope towards the central circular underground well. Its main purpose is to harvest rainwater for drinking. Traditionally, these well-pits were covered in disinfectant lime and ash, though many modern kunds have been constructed simply with cement.
• Baoli : These beautiful stepwells typically have beautiful arches, carved motifs and sometimes, rooms on their sides. Stepwells used exclusively for agriculture had drainage systems that channelled water into the fields.
• Nadi : Found near Jodhpur in Rajasthan, nadis are village ponds that store rainwater collected from adjoining natural catchment areas. The location of a nadi has a strong bearing on its storage capacity and hence the site of a nadi is chosen after careful deliberation of its catchment and runoff characteristics.
• Bhandara Phad : Phad, a community-managed irrigation system, probably came into existence a few centuries ago. The Phad system is operated on three rivers in the Tapi basin – Panjhra, Mosam and Aram – in the Dhule and Nasik districts of Maharashtra.
• Zing : Zings, found in Ladakh, are small tanks that collect melting glacier water. A network of guiding channels brings water from the glacier to the tank. A trickle in the  morning, the melting waters of the glacier turn into a flowing stream by the afternoon. The water, collected by evening, is used in the fields on the following day.
• Kuhls : Kuhls are surface water channels found in the mountainous regions of Himachal Pradesh. The channels carry glacial waters from rivers and streams into the fields.
• Zabo : Practised in Nagaland, Zabo is also known as the Ruza system. Rainwater that falls on forested hilltops is collected by channels that deposit the run-off water in pond-like structures created on the terraced hillsides.
• Bamboo Drip Irrigation : Bamboo Drip irrigation System is an ingenious system of efficient water management that has been practised for over two centuries in northeast India. The tribal farmers of the region have developed a system for irrigation in which water from perennial springs is diverted to the terrace fields using varying sizes and shapes of bamboo pipes.
• Jackwells : The Shompen tribe of the Great Nicobar Islands lives in a region of rugged topography that they make full use of to harvest water. In this system, the low-lying region of the island is covered with jackwells (pits encircled by bunds made from logs of hard wood).
• Ramtek Model : The Ramtek model has been named after the water harvesting structures in the town of Ramtek in Maharashtra. In this system, tanks connected by underground and surface canals form a chain that extends from the foothills to the plains.
• Pat System : The Pat system, in which the peculiarities of the terrain are used to divert water from hill streams into irrigation channels, was developed in the Bhitada village in Jhabua district of Madhya Pradesh. Diversion bunds are made across a stream near the village by piling up stones and then lining them with teak leaves and mud to make them leak-proof.
• Eri : The Eri (tank) system of Tamil Nadu is one of the oldest water management systems in India. Still widely used in the state, eris act as flood-control systems, prevent soil erosion and wastage of runoff during periods of heavy rainfall, and also recharge the groundwater. Eris can either be a system eri, which is fed by channels that divert river water, or a non-system eri, that is fed solely by rain