The knowledge of hydrology has been deep rooted in science of ancient India, especially in temples.
Every region of the country had its peculiar water conservation methods reflecting geographical and cultural uniqueness. Our predecessors raised small scale efficient irrigation systems for their plantations. For this, they made use of water bodies. Temples bore the responsibility of conservation of inscriptions, idols along with water.
The Junagarh inscription explains the construction of Sudarshana lake that was an artificial reservoir, built by Chandragupta Maurya in 4th BCE, completed during the reign of Ashoka and repaired by Rudradaman, a prominent Shaka-Shatrapa king, in 2nd CE. The Junagarh inscription also mentions that the lake had burst its banks due to excessive rains in 5th CE and was repaired by Skandagupta, a prominent Gupta king.
At present, in lieu of the water management and frequent droughts, we can learn from our ancestors:
Chand Baoli, Dausa, Rajasthan, India (Please see the below picture)
Rani-ki-Vav: Queen's stepwell, Gujarat, Rajasthan (Please see the below picture)
Use of water tanks (baolis and johads) in the temples
Water conservation on hilltop temples by rulers in Bundi and Kota in Rajasthan, can be learnt.
Construction of wells in Gangaikondacholapuram by Chola ruler Rajendra I.
In Rajasthan: Chand Baoli and temple in Dausa; Karnataka: Vijaypura; Maharashtra; Madhya Pradesh; Gujarat: the queen's stepwell.
In olden days, Goa had a rich tradition of water conservation and harvesting which reflected ecological principles.
The sacred tanks locally known as Devachi tali indicated that our ancestors in Goa cultivated a philosophy and way of life in which water resources were conserved and protected for sustainable use. The sacred tank in Veling, a village which lies about 5.2 km to the North-West of Ponda, has the temple of Laxmi-Narsinha, which stand testimony to the eco-cultural heritage.
Rainwater harvesting techniques: Paar system in western Rajasthan
Management of water by the local bodies:
Cholas in southern India were the ones to introduce the concept of gram sabha.
If our local administration keeps a count of management of water resources, in an autonomous manner without interference of other institutions of governance.
Mass awareness using water conservation festivals.
Irrigation techniques in ancient India mentioned in literary sources such as:
Pat system in Madhya Pradesh,
Saza Kuva in Rajasthan, mentioned in temple inscriptions of the area.
Watershed management techniques such as
"Rapat" which is a percolation tank which was used to recharge the groundwater level.
To stop flow of water into rivulets using structures such as
Bundela tank, (which were constructed mainly in the temple premises).
With frequent floods in Eastern states like Assam, Odisha and frequent droughts in Maharashtra, we need to learn water conservation techniques from our ancient temples and inscriptions.
Initiatives like Google's digitisation of Baolis in Delhi need to be appreciated and adopted further to generate a mass belongingness and awareness.
Further the appreciation mechanisms by the international organisations such as the UNESCO also motivates the local populace to keep the historical tradition of conserving water through step-wells (baolis).