Past, Present And Future Of Rainwater Harvesting In India

India is currently experiencing the monsoon. Every year, the rainy season is marred by waterlogging, submerged infrastructure, and gridlocked traffic, with some areas even being hit by flash floods. The country receives so much rainwater. What does it do with it?

Per the NITI Aayog, India has roughly 18 per cent of the world's population but controls only 4 per cent of global freshwater resources. Projects like the Jal Shakti Abhiyan are working towards conserving rainwater. But there is still room for improvement.

Ancient Rainwater Harvesting In India

Experts argue that rainwater harvesting is not just a scientific concept, but it is historically linked to India. Scriptures and historical records discuss rainwater harvesting long before the term took on its popular name and meaning. Deeply rooted in Indian history, rainwater systems were not simply designed to store water but also to act as a hydraulic buffer and mitigate floods.

Professor Jothiprakash of IIT Bombay explains this idea.

"Water resources are the primary need for survival. Rainwater harvesting isn't a new concept to India at all-it's as old as our civilisation. Traditionally, rainwater harvesting has been designed, implemented, and maintained as a sustainable water resource, not only for harvesting rainwater but also to reduce flooding. A prime example of this is the traditional temple tank network. Instead of isolated reservoirs, ancient systems utilised an interlinked chain of tanks to create 'sponge cities'."

Citing an example, he adds, "That chain of temple tanks makes a city a sponge city. Chidambaram temple tanks in Tamil Nadu are one good example; the number of temples and their associated temple tanks in Kanchipuram, Tamil Nadu, is another. The excess water of one tank goes to another, which makes no wastage of flood water."

Professor Jothiprakash further explains that these life-saving structures, as he calls them, were sustained through community action embedded in the local culture of the area. 

"These structures were built based on a sound knowledge of Vedic hydrology, a better understanding of the local geology, excellent workmanship, architectural sculptures, and maintenance through participatory management, in the name of spiritual float festivals," he said.

Also read: Concrete Jungles, Clogged Drains: Decoding India's Waterlogging Crisis

Modernisation And Urban Problems

Rapid urbanisation has paved over these natural networks. Concrete developments are often built on top of traditional catchment zones, turning seasonal rainfall into big problems. Professor Jothiprakash argues that water bodies have been destroyed in the name of urbanisation.

"When a heavy downpour happens, water always moves towards the lowest part. So, earlier, water used to get stored in tanks, recharge the groundwater table and reduce flooding. But now we have constructed there, making man-made floods," he said.

Remarking on a shift away from traditional systems, Professor Jothiprakash highlights: "We have forgotten the Vedic hydrology, and we are designing just based on the rainfall pattern. These analyses may be required for large-scale dams and reservoirs, but for simple rainwater harvesting and sponge cities, we should take into account the local hydrology, local geology, as well as local land use and land cover."

Localised Rainwater Harvesting

The need for localised rainwater harvesting is visible given the geographical extremes that India is home to. Professor BW Pandey, director of the Centre for Himalayan Studies at the University of Delhi, highlights the paradox of high-rainfall areas facing water scarcity due to a lack of catchments. 

"Rainwater harvesting has become mandatory by the Government of India as we are running short of water resources, particularly fresh water. Cherrapunji receives the highest rainfall in the world, but Cherrapunji too has a water crisis because every drop of water drains out immediately," he said.

To counter this, localised slope management projects have been created. Professor Pandey points out, "The Uttarakhand government started the Chal Khal project, in which they are arresting the water at source and generating their pool of fresh water. And there are so many successful stories in the Himalayas where these dry valleys are being regenerated again because of rainwater harvesting."

Even in arid regions, proper historical engineering prevents scarcity. Professor Pandey highlights Udaipur as a model. 

"The best example is Udaipur. Through the interlinkages of the lakes, they manage the rainwater. Even in a dry region, a dry state like Rajasthan, there is never a crisis of water in Udaipur. Because, very efficiently, all the lakes are interlinked and managing the water," he added.

Experts, however, also argue that while India may be working towards conserving and utilising every drop of its water, there is still scope for a lot more.

How the World Manages Its Water

While India works to manage its water, other nations facing similar issues like climate change and rapid urban growth have adapted their systems, utilising every drop of water that falls on their surface.

Israel stands tall as a global leader in water management, treating water not just as a utility but also as a national asset that must be cherished. Instead of letting water simply glide off its surface, Israel captures it, purifies it, and pushes it back into depleted underground aquifers. This solves the problem of severe water table depletion, which is something experienced by several Indian cities, including metros. Additionally, the nation also relies on heavy community-driven rainwater harvesting projects, wherein community centres and public structures are utilised to capture the water. This helps satisfy the secondary water needs of the nation.

China is another country that can be looked to for inspiration. China has actively perfected the modern idea of the "Sponge City" concept across dozens of its major urban centres to battle both heavy flash floods and water shortages. Instead of relying solely on pipes, drains, and concrete channels to move rainwater away as quickly as possible, China replaces solid surfaces with nature-based solutions. Urban planners suggest the installation of permeable asphalt, bioswales, rain gardens, and large urban wetlands. The core philosophy is to distribute, slow down, and retain water at its source rather than fighting it with massive concrete walls and reservoirs at the end of a drain line.

Singapore is another country that represents the gold standard for urban rainwater management. The nation employs the "Four National Taps" framework, turning a land-scarce island into a self-sufficient water model. The city-state has engineered its layout so that two-thirds of its entire land surface acts as a giant water catchment area. Rainfall dropping onto skyscrapers, roads, and residential estates is captured by a precise network of drains and canals, routing every drop into urban reservoirs rather than letting it cause urban chaos. Crucially, Singapore enforces a strict, city-wide separation between its stormwater drainage network and its used-water sewage network.

How India Must 'Flow'

For India to be climate resilient, rainwater harvesting cannot merely be a passive guideline but must be an actively pursued project. Experts suggest the incorporation of the idea into a national priority and a collective public habit. Professor BW Pandey emphasises the scale of action required: "Rainwater harvesting must be the national agenda, street-wise agenda, and the common agenda of the masses of the people of the country."

Elucidating with an example, Professor BW Pandey says that controlling rainwater at the source addresses the problem of resource scarcity and disaster mitigation. He says, "For example, if the slope's rainwater is controlled on the contours, that can avoid the flash flood. That can avoid flooding in the lower region. So, not only is it sustaining rainwater harvesting, but it is also a relief in disaster management."

A big problem in modern water infrastructure lies not only in the adoption of such systems but also in their lack of long-term maintenance. Prof. Jothiprakash calls for the community to pull up their socks, act, and take ownership of the project: "The government constructs a pond and leaves. But who will maintain it? There should be a policy on participatory management... Community participation is the key element in RWH."

To implement this on the ground, Prof. Jothiprakash outlines an actionable framework where local institutions, colleges, and corporations adopt existing, traditional water structures. "Every college, every educational institute, every company, and every industry in that locality can identify an existing, traditional water harvesting structure and other water bodies, and adopt it to maintain it. They can clean it and divert all the runoff to conventional water bodies like temple tanks, stepwells, village ponds, etc., for sustainable management of the RWH," he said.

Looking at examples from other nations, the message for India is loud and clear: modern water security requires working with water and not fighting it away. Any solution, hence, must work towards incorporating every drop of water into the system, rather than pushing it away into other sources from which it may not be able to work its way back into the cycle.