Rain Water Harvesting Techniques

Rain Water Harvesting Techniques

The most common practices followed by the farmers to conserve the soil moisture are summer tillage, field boundary bund with vegetative cover, use of farm yard manure and intercultural operation with hand/bullock drawn equipments. Farmers have followed the surface water harvesting rainwater harvesting techniques such as local percolation tank, farm pond, Tanka, Nada, Nadi, Talai, Talba, Khadin, Sar, Sagar and Samand. The water-harvesting methods differ from region depending upon rainfall, topography and soil type.

Tanka is constructed on farm in courtyard fort, etc. The shape of the Tanka is generally kept circular; however square Tankas are also constructed in buildings, forts and palatial buildings etc., for harvesting roof water, 2 m diameter and 3 m deep Tanka (capacity 10000 liter) is common. The Tanka is made on sloping land to arrest run off water in the farm however in house the construction is made on an elevated place to avoid entry of water into it.

(Rain Water Harvesting)

Talai is about 2–3 m deep, the soil scooped out from the Talai is spread around to make catchments area keeping its slope in mind special attention is paid for selection of locations such that there is adequate flow of rainwater into the Talai. Care is also taken so that loose soil does not flow along with water stream into the Talai. In contrast to the Tanka, the Talai is kept open from the top. A pucca masonry ram entrance is also provided on one side of the Talai to facilitate distribution of water using camel, donkey, bullock cart, etc. The stored water is generally used for animals.

Nada is a common method of conserving rainwater in villages. Low-lying area in between hillocks the catchments area of the Nada is 5 to 10 ha. The Nada is constructed on rangeland, barren land, pasture land and agricultural field. It provides short-term storage of rainwater and mainly used for animals. Nadi – Compared to Nada high embankment is provided around the Nadi. Depth of Nadi is kept up to 6–8 m. Catchments area of 10 to 150 ha is common for a Nadi. However area as high as 200 ha is found in certain specific cases.

(Rain Water Harvesting)

Nadi is generally constructed on sloppy area so that excess runoff water flows out without causing any damage to the embankment. Adequate cleanliness is maintained in the watershed to maintain purity or stored water. Bath is prohibited inside the Nadi. In the Nadi, water is available for whole of the year as a result it is shelter home for many wild animals and birds.

Talab – Talab is relatively shallow and spread over to more area compared to Nadi Runoff from hillocks is channels to a low-lying area in the vicinity and adequately bunded to form a Talab. It is generally constructed on rangeland. Khadin – Khadin is the ancient indigenous rainwater harvesting method mainly found in jaisalmer district. Accumulation of runoff water in between hillocks is known as khadin.

Khadin means cultivation of crops in about 60–70 ha area. The khandi water is generally used for crop cultivation under preserved moisture conditions and animals consumption.

Sar, Sagar and Samand: In certain district of Thar Dessert sar, sagar and samand are used to harvest rainwater for irrigation purposes.

(Rain Water Harvesting)