Rainwater harvesting experience in Chennai may help Hyderabad solve water shortage problem

In 1995, Professor Sekhar Raghavan noticed an unusual phenomenon: the tap water in Chennai had become brackish. This occurred against the backdrop of declining groundwater levels, causing seawater to seep into the city's underground freshwater reserves, making its use increasingly difficult.

The problem was not a lack of rainfall, as Chennai received a significant amount of rain. However, most of this water flowed into roads and drains into the sea instead of replenishing the groundwater beneath residents' homes.

This fact prompted Raghavan to ask himself: if rain falls over the city, why is so little of it conserved? His answer was to convey the idea of rainwater harvesting to the public. Armed with a bicycle and a simple message, he began visiting neighborhoods, going door-to-door to convince residents to collect rainwater and direct it back into the ground.

Nearly three decades later, his campaign offers a valuable lesson to another Indian city facing a water deficit—Hyderabad.

When it rains, but wells dry up

The city, home to about 1.5 million people, struggles with a severe shortage of drinking water. Causes include uneven regional distribution of water resources, competition between agricultural and industrial needs, and monsoon deficits.

According to data provided by the State Irrigation Department, more than 330 out of over 600 mandals in Telangana were classified as drought-affected, and only about 500 of the state's more than 6000 lakes contain water.

Pressure on water resources is evident in the city's growing reliance on tankers. Daily orders have risen to 6,000–8,000, prompting Ashok Reddy, Managing Director of the Hyderabad Waterworks and Sewerage Board, to instruct staff to bring in additional tanker operators and begin their registration.

In some parts of Secunderabad Cantonment and on the outskirts of Hyderabad, residents report receiving drinking water only once every three or four days. It is also reported that one of the city's main reservoirs has dropped to about 13% of its capacity.

However, the shortage is not only related to the amount of incoming water but also to how much the city can retain it. This is where the Chennai experience becomes relevant.

One bicycle, one neighborhood at a time

When Raghavan started his campaign in 1995, rainwater harvesting was not a common practice for most urban households. He aimed to change this situation by explaining how rainwater collected from roofs, driveways, and other surfaces could be filtered and directed into replenishment systems, allowing it to seep into the soil and restore underground aquifers.

Instead of letting rainwater run off into drains, households could capture it and help replenish the groundwater they depended on.

Nevertheless, convincing people proved harder than explaining the scientific principles. Raghavan cycled through neighborhoods, talking to residents and encouraging them to install collection systems. Many initially rejected the idea, but he continued to work with communities, demonstrating how it could be implemented.

Through the Rain Centre, which he headed, he also collaborated with teams of plumbers and well diggers to survey systems across the city and demonstrate rainwater harvesting on model houses.

How Chennai turned an idea into law

In October 2002, the Tamil Nadu government passed legislation making rainwater harvesting mandatory. In June 2003, a decree extended this requirement to all existing buildings across the state, including Chennai.

Property owners were required to install systems by October 11, 2003. Non-compliance could result in fines or disconnection of the municipal water supply.

A government announcement in November 2003 stated that 99.5% of Chennai residents had implemented rainwater harvesting in their homes and complexes.

However, installing a system and ensuring its functionality are two different processes. An inspection conducted by the Rain Centre in a residential area between October and November 2003 showed that about half of the residents had implemented rainwater harvesting inadequately.

Even among those who installed systems correctly, many focused only on collecting rainwater from roofs, ignoring another important source: rain falling on the rest of their property.

In housing complexes, this surface runoff could account for twice the volume collected from roofs. Although this water may not be suitable for direct domestic use, it can still be directed into the soil to replenish groundwater. As it moves through the soil, natural filtration helps remove pollutants.

The missing piece: what happens outside the roof? Raghavan's work also highlighted a broader gap in Chennai's approach. While households were responsible for collecting rainwater on their premises, public spaces represented another opportunity. Roads, parks, and playgrounds receive significant amounts of precipitation. Nevertheless, most of the water running off Chennai's storm drains is directed to the city's waterways and ultimately discharged into the Bay of Bengal.

Instead of letting all this runoff disappear, the Rain Centre advocated for directing appropriate urban runoff into replenishment systems. However, this requires careful planning. Road runoff carries solid waste, fine silt, and other pollutants that can clog collection systems. Therefore, systems must incorporate filtration, waste removal, and regular maintenance.

The city also needs adequate open spaces and properly designed replenishment systems to prevent water stagnation and flooding. In other words, rainwater harvesting is only one part of water management.

What the Chennai experience teaches Hyderabad

The results of Chennai's efforts became clearer after the return of rains. Tamil Nadu received below-average rainfall in 2003 and 2004, which made it difficult for residents to immediately observe the benefits. The following year brought heavier rains, which allowed for a clear demonstration of what could be achieved with functioning collection systems.

After the 2005 rains, the Rain Centre recorded an increase in groundwater levels by approximately 20 feet in the areas under its control, prompting the team to continue its work. For nearly 15 years, rainwater harvesting helped Chennai strengthen its groundwater reserves. However, the 2019 water crisis revealed limitations related to infrastructure that was no longer being maintained properly. Clogged filters, abandoned recharge pits, and poorly functioning systems weakened the effect of the initial initiative.

Today, Chennai is exploring additional approaches, including 'sponge parks' and underground rainwater harvesting systems, to improve its ability to retain precipitation. For Hyderabad, the lesson is not simply to copy Chennai's legislation or install collection systems on buildings. It is about creating a system where households, communities, and civic authorities share responsibility for rainwater harvesting, maintaining recharge systems, and protecting groundwater.

Raghavan's journey began with a brackish tap and a bicycle. It was followed by a city-wide dialogue that helped turn a lost resource into a priority of urban water resource management.

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thebetterindia.comOctober 28, 18:30

Can Chennai's solution to the water problem help Hyderabad cope with the water crisis?

Hyderabad is facing a severe water shortage: the level of one of its main reservoirs has dropped to 13%, and 6000 water tankers are ordered daily.

A possible solution lies in a simple idea that helped Chennai overcome its own water crisis. In 1995, Professor Sekhar Raghavan noticed an alarming fact: tap water had become saline because the lowering of groundwater levels allowed seawater to seep in.

Despite abundant rainfall, Chennai was losing a lot of water. Instead of waiting for external intervention, it began actively promoting rainwater harvesting. His concept was simple: collect rainwater from roofs, roads, and other surfaces, filter it, and direct it to replenish underground aquifers.

He personally visited homeowners, persuading them to implement this system, although many initially rejected his efforts. In 2003, the state of Tamil Nadu made rainwater harvesting mandatory for buildings. Reports indicate that the groundwater level rose by almost 20 feet, which contributed to improving Chennai's water security.

For about fifteen years, the city benefited from this approach. However, a problem arose: due to insufficient maintenance, clogged filters, and neglect of drainage pits, many systems weakened. When Chennai faced another severe drought in 2019, the city once again found itself dangerously close to exhausting its drinking water.

Today, Chennai is studying solutions such as 'sponge parks' and underground rainwater collection systems to increase resilience to water problems. The main lesson is that rainwater harvesting is not just about installing systems, but also about their constant maintenance, protecting groundwater, and maximizing the use of every drop.

Given the growing strain on water resources in Hyderabad, the question arises: can Chennai's experience offer a way forward? Should Hyderabad make rainwater harvesting a higher priority?

thebetterindia.comOctober 28, 06:32

Children in Odisha study water conservation using Sal leaves and clay in forests

Unusual experimentation on water conservation has begun in the forests of Keonjhar district in the state of Odisha. The idea was for children to learn how to retain moisture by observing nature, using only a Sal leaf, a little clay, and a small depression in the ground.

The Lesson Hidden in the Leaf

During a walk through the dry forest slopes near the village of Khaladipani in Keonjhar district, a local elder stopped next to a curled Sal leaf. A thin film of dew had condensed in its cup-like curve, retaining moisture despite the surrounding soil drying out under the heat. For the children accompanying him, this became a small observation behind which lay a broader question: if a leaf can capture and retain a small amount of water, can they replicate this ability on land where water is a scarce resource?

The elder, known among locals as the 'jungle master,' encouraged the children to try. Instead of using plastic sheets or factory containers, the children began conducting experiments with Sal leaves and clay, creating small pits capable of collecting and holding water. This experiment was documented by Biswabijayini Mohanty in a report published by Village Square on September 16, 2026, titled 'The Water Conservation Lesson from a Leaf.' The report described how an observation during a forest walk turned into a practical water conservation exercise, where children learned through trial, error, and close attention to the environment.

How the Children Made the Pits

The children dug shallow depressions at the edge of the forest using simple tools, branches, and their hands. However, they soon encountered a problem: the loose soil absorbed the water poured into the pits before it could be retained. The jungle master helped them revise the design.

First, they laid wide Sal leaves on the bottom and sides of each depression, overlapping them like tiles. Then, they spread clay soil over the leaves, compacting and leveling it until the hollow took the shape of a shallow bowl. These two materials served different functions: the layer of leaves helped support the clay while drying, and the compacted clay formed a base designed to slow down water penetration into the surrounding soil. The children repeated this process, allowing the clay to harden before filling the pits. In about two weeks, they created a network of small water-retaining depressions along the forest boundaries. According to Village Square, the pits were generally no deeper than a forearm and rarely wider than a large dinner plate. The construction did not use plastic liners, expensive equipment, or complex engineering; the materials were taken from the surrounding landscape, and the method evolved through observation and experimentation.

When Rain Tested the Idea

These pits were intended to hold water during dry months. But after several days of rain, runoff washed away the loose soil down the slopes, turning the surrounding water sources murky. However, the pits seemed to retain relatively cleaner water. The explanation partly lies in how water behaves when allowed to settle. Rainwater flowing over open ground can carry suspended soil particles and other sediments. When this water collects in a relatively calm depression, heavier particles gradually settle at the bottom, leaving the water above less turbid. The report also records sightings of wild animals, including sambar deer, rabbits, mongooses, and squirrels, observed drinking from these pits. Nevertheless, there is an important distinction between water that looks clean and water that is safe to drink. The report lacks results from laboratory tests confirming the potability of the water collected in these pits.

What Science Says About Sal Leaves and Water

The principle underlying the experiment has parallels with traditional agricultural methods documented elsewhere in Odisha. A study by Dr. Prasanta Kumar Mishra, a leading scientist at the Central Research Institute of Dryland Agriculture, describes how tribal farmers in the village of Pakanaghon in Kandhamal district use Sal leaves as mulch in turmeric fields. The report, published by LEISA India, notes that farmers spread a layer approximately 20–25 cm thick on their fields before the monsoon season. The leaf cover helps retain soil moisture, reduces runoff and soil loss, suppresses weeds, and protects the soil from the direct impact of raindrops. Mulching works by covering the soil surface, reducing its exposure to direct sunlight and wind, and helping to slow evaporation. It can also reduce the impact force of raindrops on the ground, limiting soil particle displacement. Depending on the soil type and rainfall conditions, this cover can allow more water to remain available in the soil.

The experiment in Khaladipani uses Sal leaves differently: instead of spreading them across agricultural fields, the children place them under a compacted clay liner in small depressions. Both methods demonstrate how the local Sal can be used for moisture and soil management. The children are not simply instructed about water scarcity or the need to protect forests. They are encouraged to observe the leaf, understand its function, test a hypothesis, and learn from subsequent results. This is a practical starting point for environmental education.