Water Supply

“Does Mumbai feel the need to conserve water?” asked Sanjay Ubale, executive board member of Mumbai First at a conclave about water in Mumbai. With easy availability of water from seven reservoirs, the city has the best per capita water ratio in India, and so, there is less incentive to conserve water or practise rainwater harvesting, he explained. Why would societies spend funds to store water for future use when they are getting water at highly subsidised rates round the year, he asked. Statistics too suggest the same.  Approximately only 3000 societies of the total estimated 20,000 societies in Mumbai…

Mumbai may have witnessed heavy rains but one must not forget that the city is still reeling under a 10% water cut since June 5, 2024. On the one hand water levels in the reservoirs are depleting, and on the other hand rainwater continues to flow out. In such a scenario, rainwater harvesting can be the game changer for Mumbai. If done right, it ensures water supply for individuals, fights larger water crisis and might help reduce floods too.    Urban local bodies (ULB) like the Brihanmumbai Municipal Corporation (BMC) have been encouraging housing societies to set up rainwater harvesting…

Bengaluru has experienced extreme weather fluctuations this year. After a severe heatwave, the city enjoyed a brief respite with heavy showers, resulting in a record 111.1 mm of rainfall earlier this month. While Bengaluru received excess rainfall, the rest of the state is grappling with a 38% monsoon deficit, affecting water storage levels in reservoirs. The city is still facing water shortage despite heavy rains. In this multi-part series, analysts at the OpenCity water datajam, examined the level of water security (or lack thereof) in the areas/wards and provided insight into the redressal mechanisms: Part 1: Is your neighbourhood ‘water-secure’?…

(In Part 1, data analysts explained how they arrived at a definition of water security. In Part 2, the analysts explained the methodology used in estimating the Cauvery index and the results have been obtained. In continuation, part 3 will explain the methodology used in estimating the remaining indices and its results) Groundwater index Borewell count: The OpenCity borewell dataset was used to map borewells into Bruhat Bengaluru Mahanagara Palike (BBMP) wards and compute the number of borewells per ward. Assuming an average yield of 5,000 litres/day, water supply from borewells was normalised with ward population and the wards were…

(In Part 1 of the series, data analysts explained how they arrived at a definition of water security and created a location-specific index. In Part 2, the analysts will explain the methodology used in estimating the use of the Cauvery index and how the results have been obtained) The variables (below) were indexed and weighted with the Cauvery index, which was prioritised due to its significant impact on Bengaluru’s water security. Groundwater and land-use indices, being interdependent, received equal weights, followed by the governance index. Here is a summary table: Parent IndexVariableWeight AssignedCauveryCauvery supply to Ward1GroundwaterBorewell Water supply (litres/person/day)Ward area…

Bengaluru’s water crisis hit new lows in March 2024, which led to disruptions in water supply. There are areas in the city where water supply is irregular, expensive and unpredictable, bringing the daily lives of many communities to a standstill. It was this issue that made us, as a group, tackle the issue of water security at the Bengaluru Water Datajam held by Opencity.in in March. The notion of water security is a tricky problem to address. It depends on multiple factors like ecological security, risk management of the city, to name a few (Aboelnga et. al., 2019). Therefore, we…

The devastation that hit the coastal parts of Tamil Nadu and Chennai during the December 2023 floods still haunts the people affected here. Just five months later, the city is already staring at a potential water shortage. Reservoirs serve as the main source of water supply to Chennai residents. However, Veeranam Lake reached dead storage on February 28th due to a lack of inflow from the Mettur dam. As of the lake storage report of the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) on May 27th, the reservoirs currently hold only 42.28% of their total capacity. The CMWSSB proposes…

Sneha (name changed) decided to buy a flat in a gated community in Bengaluru this year. She was worried about the availability and sufficiency of water supply. She ticked off her checklist by asking one question to the builder: “How many borewells are there?” But could she have done more to assess water security in her new home? “Beyond that one question on borewells, no one could ask anything more,” she says, adding: “It is hypothetical, whether these borewells would supply the required water. Everyone felt that the use of tankers was inevitable. And that eventually the government would solve…

With India witnessing one of the most scorching summers, water crisis is looming across many cities in the country. India's main reservoirs have hit their lowest March levels in five years, according to government data, indicating a strain on drinking water and power availability this summer. As per Central Water Commission (CWC) data, the 150 reservoirs monitored by the central government, which supply water for drinking and irrigation and are the country's key source of hydroelectricity, were filled to just 40% of capacity in March 2024.  India's hydro generation in the last 10 months from last April is down by…

With the onset of summer, Chennai has already started facing water woes. Veeranam Lake, one of the sources of drinking water supply for Chennai has dried up. Meanwhile, the storage level in Cholavaram Lake has come down to 9.99%. As of May 5, the reservoir sources in the city have a storage of 49.42%. Will Chennai face yet another drought like in 2019? This is one fear that residents of the city come face to face with every summer. And this year seems to be no different. To know how the Chennai Metropolitan Water Supply and Sewerage Board (CMWSSB) is…