বিজ্ঞান বিষয়ক
Traditional water harvesting methods in India, with special reference to Barak Valley, Assam
Dr. Pinki Purkayastha (Chandrani)
Director: CREESS, New Delhi: India
12 February 2021
Water has been harvested in India since antiquity. Our ancestors were expert in the art of water harvesting. They harvested rain drops directly from rooftops, they collected water and stored in tanks, built in their courtyards. From open community lands, they collected the rain and stored it in artificial wells. They harvested monsoon runoff by capturing water from swollen streams during the monsoon season and stored it various forms of water bodies. They harvested water from flooded rivers, they channelized water from Wetlands like Haors and Beels with the help of drains and canals. Carried water from streams to the plains with the help of bamboo pipe lines and in many more ways.
Though India is a land of diversity, stating from Kashmir to Kanyakumaki and Gujrat to Assam, everywhere we find existence of different types of water harvesting systems designed and maintained by following the traditional methods and techniques of different communities native to those particular areas. Some of these traditional techniques, their location and respective local names are as follows:
(source-http://cpreec.org/)
India has a rich history of water harvesting systems. The excavations at Harappa and Mohenjodaro reveal deep rectangular constructions that were probably the earliest tanks built in India. Few chronological evidence of water harvesting systems of the country are as follows:
Most important thing associated with the traditional systems of water harvesting is their technology, pattern, and design. Those systems were built considering the ecology, rainfall pattern and the geography of the particular area. In the hills and mountainous regions where there are plenty of streams, simple engineering structures were used to divert the water into channels that fed the fields. The structures became more sophisticated and much bigger when the streams turned to rivers. In the arid and semi-arid regions, where the streams are more seasonal, the diversion channels first led the water to a storage structure like a tank for later use. Storage systems to collect just runoff from the watershed were also built. In the flood plains, several unique systems to control and harness the floodwaters were devised. In the coastal areas where there is danger of river water turning saline, several ingenious ways came up to regulate the flow of saline water. In regions with good groundwater aquifers, dugwells with innovative methods to lift the water were in use. Deep wells were dug in the beds of tanks and rivers, both to serve as a source of good water when the water recedes and also to recharge the groundwater when they are fully submerged. In areas where rainfall is the only option, people devised methods to literally “catch rainwater where it fell”. People being child of nature , knew the needs of water harvesting and fully aware of the ecology, geography, geology of their own location in their own way. In our Barak Valley, ponds (Dighi and Pukur) are the most common feature of every locality. But due to continuous increase in population and high rise buildings, many of such ponds are getting filled up and encroached. As a result ground water is facing severe exploitation. As we have traditional knowledge in one hand and modern scientific knowledge on the other, this is high time to conserve nature and rain water by water harvesting. Storage of water by forming water bodies leads to the percolation of standing water into the ground and recharging the water table as well. Wells in the surrounding areas have plenty of good water that increases green cover in the surrounding areas. These systems help in reduction of floods and runoff and protect life and livelihood as well......
Save water.. save future….