Traditional water  harvesting methods
The knowledge of  hydrology is deep rooted in the science of ancient India. Our ancestors applied  the knowledge in water resource engineering. They designed and constructed dams  and a variety of water structures much earlier than the consciously believed  Greek, Roman or other ancient civilizations. Every region of our country had  its own water harvesting techniques, reflecting the geographical peculiarities  and cultural uniqueness of different communities.

Rajasthan, a large  part of which is covered by the Thar Desert, has had a long tradition of water conservation.  For instance builders of the famous Bundi and Chittorgarh forts had the vision  of exploiting the natural catchments in the forts created by undulating  hilltops. Rainwater was collected in several ways and water flowing down the  hill slopes was also stored in a water body. Two pictures below of Bundi Fort  illustrate it. Picture- 1 shows a water path i.e. rainwater flowing down the hill was  purified by a jaal (sieve) between the two structures. It then flows into the  water body and gets accumulated as seen in picture - 2.

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Talab/ Bandhis
Talabs were  reservoirs. They could be natural, such as the ponds (pokhariyan) at  Tikamgarh in the Bundelkhand region or could be man-made, such as the lakes in  Udaipur. A reservoir area of less than five bighas was called a talai;  a medium sized lake was called a bandhi or talab; bigger lakes  were called sagar or samand. The pokhariyan served the  purpose of irrigation and drinking. When the water in these reservoirs dried  up, the pond beds were used for cultivation.

Johads
Johads, in Rajasthan,  were small earthen check dams built to capture and conserve rainwater, thus  improving percolation and recharging ground water1.

Baoris / Bers
Baoris or bers were community  wells, found in Rajasthan, that were used mainly for drinking. Most of them are  very old and were built by banjaras for their drinking water needs. They  could hold water for a long time because of almost negligible water  evaporation.

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Jhalaras
Jhalaras were man-made tanks, found in  Rajasthan and Gujarat, essentially meant for community use and for religious  rites but not for drinking. Often rectangular in shape, jhalaras have  steps on three or four sides. They were ground water bodies which were built to  ensure easy and regular supply of water to the surrounding areas.
The jhalaras collected subterranean  seepage of a talab or a lake located upstream.

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Water Temples or ‘Step Wells’
Another most unique example for  harvesting rainwater and providing water for drinking purpose in arid parts of  our country was the step well.

 
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Step wells are also  called water temples of India. The idea to construct step wells  was initiated due to the need to ensure  water supply during the period of drought. Some of the step wells were dug very  close to tanks to get drinking water    throughout   the year. Step wells  are also called Vav, Vavadi, Bawdi, Bawri,  Baoli, and Bavadi   and can be found  in Gujarat and Rajasthan.

Adalaj-Vav is a  very popular step-well i.e. about 20 kms from Ahmdabad. It is made in the form  of a temple that ends into a well. The well is about six storeys below ground  level. Picture 6 illustrates the depth of the well.

Kunds
Kunds, covered  underground tanks were developed for tackling drinking water problems. Usually  constructed with local materials or cement, kunds were more  prevalent in the western arid regions of Rajasthan, and in areas where the  limited groundwater available is moderate to highly saline. In such conditions, kunds provided convenient, clean and sweet water for drinking. They were  also prevalent in Gujarat and Uttar Pradesh.
There are many more such kunds that have met the water needs of  the people of Rajasthan and other states over centuries. See picture below (Pic  7 is copyright Centre for Science and Environment or CSE)

Pic.-7

Pic.-8  Brahmkund in Vrindavan