July 6, 16:30

City Facing Water Shortage Now Teaches India Water Conservation Methods

In the summer months of 2019, Chennai looked like a city experiencing a severe water shortage. Long queues of plastic containers were visible on the streets before the arrival of tankers. Water was running out of taps in residential buildings, hotels reduced laundry services, and restaurants shortened their operating hours. Some offices even asked employees to work from home due to non-functional toilets.

Water Resource Situation

For a coastal city whose life is dictated by the rhythm of monsoons, this picture was shocking. That year, all four major reservoirs of Chennai were nearly dry. Around ten million people found themselves in a situation many called the 'Zero Day' moment—a critical point where the city's water supply system begins to fail under demand pressure.

However, the water crisis in Chennai began long before 2019. Long before the city became an example of urban drought, it had already discovered part of the solution simply by refusing to use it.

Period of Intensive Water Withdrawal

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City Facing Water Shortage Now Teaches India Water Conservation Methods

In the 1990s, Chennai's population was about 3.8 million, and the existing city water network could not cope with such growth. Families queued at public taps, and those who could afford it bought water from private tankers. Thousands of households drilled wells, extracting groundwater faster than it could replenish.

The consequences of this quickly became apparent. As the groundwater level dropped, seawater began to infiltrate the underground aquifers. In many areas, well water took on a salty taste, and residents recalled brushing their teeth with water that tasted of the sea.

Discovery of Old Methods

According to water conservation specialist Sahara Raghavan, the turning point came in 1995 when he studied old land records. He discovered not a new technology, but an old practice. Villages around Chennai previously relied on interconnected reservoirs, ponds, lakes, and canals to replenish supplies, which were designed to collect rainwater during monsoons and allow it to slowly return to the ground. The principle was simple: all fresh water starts as rain.

Legislative Mandate for Rainwater Harvesting

Raghavan adapted this wisdom for the growing metropolis. Instead of restoring entire village systems, he proposed a more practical solution—collecting rainwater from rooftops. Rain falling on roofs, terraces, and paved surfaces could be directed through pipes and filters into underground aquifers or storage reservoirs.

Initially, the idea faced difficulties in gaining support. However, politics intervened. In 2001, state leadership included rainwater harvesting in Tamil Nadu's water strategy. By 2003, the state made this practice mandatory for all buildings, both old and new. The rules were strict: buildings without functioning rainwater harvesting systems risked losing connections to water and sewage, and obtaining completion certificates and property permits depended on compliance with these standards. Thus, the law transformed water conservation from a personal choice into an infrastructural task for the entire city.

System Testing During Rains

The first serious test came in 2005. That year, Chennai received almost twice the usual amount of rainfall. But this time, most of that water did not run off the surface. Thanks to thousands of installed rainwater harvesting systems, the rain seeped into the ground. The well recovered, and the groundwater level in several parts of the city rose by almost 20 feet. For nearly a decade, this replenishment served as a buffer, demonstrating that Chennai's water crisis was not always related to scarcity, but often to storage problems.

Nevertheless, rainwater harvesting required one condition—maintenance. And this is where Chennai made mistakes. Over time, filters became clogged, and drainage pits were not cleaned. In many buildings, rainwater harvesting systems existed only formally. By 2019, investigations revealed over 41,000 buildings without such systems, and thousands more had damaged or poorly maintained installations. When the reservoirs emptied again that year, the consequences became clear. Rainwater harvesting should never have been a one-time event; it requires regular monitoring, upkeep, and public participation.

This time, Chennai's response went beyond just rooftops. The city is working to restore over 80 ponds before the rainy season by clearing them of silt, strengthening banks, and removing illegal constructions. For a long time, these ponds were considered barren lands, but now they are being integrated into Chennai's flood management and groundwater recharge strategy.

Simultaneously, the city has begun creating rainwater collection parks, known as 'sponge parks'. The first large-scale such park in the Madur MMDA Colony area, announced for 2025, will feature a surface sports field, including a football pitch, walking paths, and courts. Beneath it, the park will be able to accumulate up to 1.2 million liters of stormwater. The city is also testing more modern technologies. Using German trap technology, Chennai has started installing modular underground systems beneath parks that allow for collecting and filtering rainwater faster than traditional recharge wells. Some of these systems can hold millions of liters of water.

Evolution of Water Approach

This marks a broader shift in thinking. First, there were rooftops, then ponds, and now entire areas are being redesigned to absorb rain rather than divert it. Chennai's history ultimately speaks of memory. The city once knew how to live with the rain. Over time, this knowledge was buried under concrete, rapid expansion, and neglect. However, Chennai's path also shows that policy can change behavior, and old ideas can help solve modern problems.

www.aajtak.inJuly 2, 07:51

Delhi's water supply system faces problems: from summer water shortages to rainwater runoff into sewage

With the start of July, the first monsoon rains began in Delhi, following a period when residents in many areas experienced severe water scarcity. In May and June, with temperatures reaching 45–48 degrees Celsius, people were seen queuing at government and private tankers with buckets and pipes.

The problem of rainwater runoff

However, the situation has drastically changed: millions of liters of clean, fresh rainwater are flowing through dirty drainage ditches into the Yamuna River and leaving the city. This annual phenomenon is not a natural wonder or a disaster, but rather a reflection of serious systemic failures caused by government negligence, bureaucracy, and municipal authorities. Since this problem has existed for decades, an effective rainwater harvesting system has not been established.

Potential and reality of water collection

The total area of Delhi is about 1,486 square kilometers, and it receives an average of 611 millimeters of rainfall annually. If all this volume of water were directed into the ground or conserved, Delhi could save approximately 907 billion liters per year. This reserve would be enough for the needs of the entire population of Delhi for about 270 days. Although complete conservation of all precipitation is impossible, achieving a level of 40–50 percent would significantly benefit the city's residents.

Nevertheless, in practice, less than 5 percent of all this water penetrates the soil. More than 95 percent flows along the streets into drainage systems, causing flooding situations.

Contrast between demand and supply

During the summer period, the water demand in Delhi reached 1,200 million gallons daily from March to June. However, the Delhi Jal Board could only provide about 930–950 million gallons per day, resulting in a deficit of approximately 250 million gallons daily.

Another indicator shows that if 100 millimeters of good rain falls in one day and all this water is conserved, this volume would be enough to fully supply Delhi for 14 days.

Main causes of the problem

There are three main reasons for this problem. Firstly, there is disregard for regulations. Delhi has a requirement that all new buildings or structures over 100 square meters must have a rainwater harvesting system. However, out of approximately 17–18 million buildings, only 1–2 percent have this system operational. Most often, obtaining a certificate requires showing a hole on paper, which is then filled with earth and used for parking, without a reliable verification mechanism.

Secondly, state-owned installations do not function properly. Water collection systems installed in government schools, flyovers, and metro stations are in poor condition. These systems should be cleaned before the rains, but, as in this year, more than 60 percent of locations did not undergo such cleaning. As a result, upon the first rain, the soil clogged these reservoirs, and the water flowed down the streets instead of penetrating the ground.

Thirdly, there is no single responsible authority for water supply in Delhi. The Delhi Jal Board handles water supply and billing, MCD is responsible for cleaning small drains, PWD oversees the drainage systems of major roads, and DDA owns large city parks and open spaces. When flooding occurs during the rain, each department blames another, and the core issue gets lost.

Conclusions from official reports

According to a report by the country's largest state audit body, the CAG, an important conclusion was drawn: 51–53 percent of the water treated in Delhi is lost before reaching consumers due to leaks, theft, and damaged pipelines, whereas the acceptable loss rate should not exceed 15 percent. The CAG also noted that the Delhi Jal Board lacks a clear long-term water supply plan.

The impact of concrete on the problem

Another serious problem in Delhi is the widespread coverage of the city with cement and concrete. When rainwater falls on the soil, about half of it seeps into the ground. But when the same water hits roads covered with cement or tiles, 90 percent of it runs off without stopping. Parks, sidewalks, and streets in Delhi are almost entirely paved with tiles and cement, which prevents water from penetrating the ground.

Government actions

The Delhi government has initiated several major projects, including the construction of large ponds along Pushpa Road and the Yamuna River to retain rainwater and allow its infiltration into the ground. Furthermore, the restoration of about 250 old ponds, such as Bhalswa and Sanjay, has begun.

However, there is a significant shortcoming: all these works are being carried out on large government territories far from the city, while the main population of Delhi resides in areas like Samghan Vihar, Patel Nagar, Uttam Nagar, and Karol Bagh, where no local-level work is being done. Retaining water only along the banks of the Yamuna will not prevent groundwater rise in Karol Bagh. The problem will not be solved until water is retained in every neighborhood within that same neighborhood.

Proposals for solving the problem

A specialized body must be created that will bear full responsibility for water issues to eliminate mutual accusations between various departments. The inspection of water collection systems in large buildings should be conducted not only based on paper reports but also through manual physical audits, flow meters, and digital water meters.

It is also necessary to establish small retention pits in parks in every neighborhood so that the water remains within its own area and seeps into the ground. Additionally, when constructing new roads and sidewalks, tiles and blocks that promote water infiltration into the ground should be used.

Private tanker trade

A significant portion of Delhi's water supply comes from private tankers, but precise data on this sector is unavailable because the Delhi Jal Board only accounts for its own tankers. Private transporters illegally draw water from wells, the Yamuna, and sometimes from the board's supplies.

There is a dark side to this sector: complaints about theft from board wells, bribes to the police, and the operation of wells without permits are common. People prefer to buy expensive private water instead of waiting for government tankers, which fuels the growth of this business.