GENRE: Explainers

Despite water scarcity, Bengalureans let hundreds of litres of reject RO water down their drains every day without much thought. For every one litre of filtered water, RO (Reverse Osmosis) water purifiers waste 3.5 litres of water. But many Bengaluru households don't even require RO purifiers. “RO water purifiers have become a status symbol. Many residents do not know the purpose of the purifiers, let alone the water quality,” says Vinosh M Paul, independent water purifier sales and service technician in Bengaluru. So, do you need an RO unit?  What are RO water purifiers?  Reverse Osmosis (RO) is an advanced…

Ever stepped out to be hit by a blistering wave of heat? When the surroundings felt like a furnace and the body seemed to give up from exhaustion? This is how it was a week ago, when in many parts of India, including Delhi, the mercury touched 40 degrees Celsius, before sudden rainfall drastically lowered temperatures. The high humidity pushed the 'feel-like temperature' to almost 50 degrees Celsius, and the heat wave disrupted daily life.   Now, imagine a long battle with unrelenting heat for weeks or months, stifling communities and threatening livelihoods. Heat waves and chronic heat stress may…

From the Western Expressway Highway if you turn left, you start to see mangroves beyond which lies the Mithi river. Go further towards the Kala Killa bus depot at Dharavi, and you will see a green fence beyond which lies an urban forest. This is the Maharashtra Nature Park that the Maharashtra Regional Development Authority (MMRDA) built with the support of the NGO World Wide Fund for Nature India, starting from 1983. Architect Shriya Bhatia cites this as an example of blue green infrastructure (BGI). Built on a former garbage dumping ground, the park houses indigenous plant varieties and an…

I remember the first time I set up my kitchen garden and finished sowing. The joy in the germination, of seeing something grow is the best. I would talk to my plants every day, water them lovingly, and carefully follow all the advice people gave me, to keep them healthy—adding compost, avoiding overwatering, and sticking to companion planting guidelines. But then they struck!!! PESTS. About a month in, I noticed tiny black insects covering the stems. I later learned they were aphids. Over the years of kitchen gardening, I’ve battled mealybugs, aphids, stem borers, fruit flies—you name it. Some seasons…

Nearly 72% of Bengaluru gets contaminated water. Depending on whether residents get their water from borewells, tankers or from the Cauvery River, the quality varies from one area to another. According to a 2018 survey, 24% of Bengaluru households receive water from both borewells and Cauvery, with a hardness level above the prescribed limit of 200 milligrams per litre (mg/l).  Another study found Total Dissolvable Solids (TDS) range crossing 1,000 parts per million (PPM) per litre in Bengaluru, when the acceptable range is a maximum of 300 PPM. TDS refers to the amount of organic and inorganic material dissolved in…

Although Mumbai has sufficient groundwater, experts opine that it is depleting at a fast rate due to rapid urbanisation and massive construction projects. There's also a lack of clear groundwater regulations and systematic records of private borewells and dug wells.  This guide provides a comprehensive overview of the rules, processes, and penalties associated with digging a borewell and extracting groundwater in Mumbai. Getting permission for groundwater extraction What are the rules for digging a borewell and extracting groundwater in Mumbai? In Mumbai, borewell digging and groundwater management are regulated under the Maharashtra Groundwater (Development and Management) Act 2009. According to…

Urban Heat Islands (UHI) are areas within cities that experience significantly higher temperatures than their rural counterparts due to human activities, concretisation, and lack of vegetation. Bengaluru, the fifth most populous metropolis (Census of India, 2011) and one of the rapidly growing cities in India, is no exception. In the last two decades, the city has seen a rapid rise in built-up area from 37.4% to 93.3%. The pressure of urbanisation has not only affected the natural and ecological resources but is also impacting the city’s livability because of rising temperature levels. Unlike sudden disaster events like landslides or floods,…

Groundwater is a vital resource in Chennai, especially given the city's water scarcity challenges. Of the 51 revenue blocks in Chennai where groundwater is extracted, 46 were overexploited in 2024, as reported by Citizen Matters. That's why strict rules are in place to ensure sustainable usage and to prevent over-extraction. Chennai is the first Indian city to have a comprehensive automatic groundwater monitoring system, introduced in 2021, with 200 groundwater monitoring devices and 20 rain gauges across 15 zones, to assess the groundwater level across the city. However, experts point out that not much is being done with this data.…

In its 2025-26 budget, the BMC declared that it would start levying water charges on unmetered properties. To this end they have already started a survey of properties to fix a rate for these water charges. But what does this mean for the people of Mumbai? Who will be affected by this? Here’s what you should know about the decision that the BMC has taken. What is an unmetered property? Any premises which does not have a meter to measure the consumption of water is called an unmetered property. Most unmetered properties are in Mumbai City (excluding the suburban districts).…

The dependency on the Cauvery River for water and the depleting groundwater levels, keep Bengaluru on the edge of a crisis every summer. As the city expands rapidly, it faces a significant challenge – how to manage groundwater sustainably, while meeting the growing demand. Borewells are a common solution for water needs, but strict regulations govern their digging and usage. Bengaluru is classified as a 'notified area', due to overextraction in many places, so borewell digging and extraction are strictly regulated.  However, poor implementation of rules by civic utility bodies undermines their effectiveness. So, how can a Bengalurean dig a…