Mumbai’s first-ever desalination plant has got many people excited—urban policy wonks about tapping into the seawater that surrounds the city, the Maharashtra government about scoring yet another first, the Brihanmumbai Municipal Corporation (BMC) about going beyond rain-fed reservoirs in the city and dams hundreds of kilometres away, and the Israeli company about the Rs 3,900 crore project at Manori.
To be situated near a village across the Manori Creek, on the northwestern edge of Mumbai, the proposed desalination plant that Israel’s IDE Technologies will build will use reverse osmosis technology and operate for 20 years and will add 200 million litres a day (MLD) to Mumbai’s water supply. Spread over 12 acres in a sensitive coastal zone, the project was approved by the Maharashtra Coastal Zone Management Authority on April 7 and received the Coastal Regulation Zone clearance of the Union environment ministry on April 28 this year.
On paper, both the agencies have listed the safeguards to be followed, such as protecting mangroves and fishing livelihoods of local residents and the disposal of concentrated brine. On the ground, it is anybody’s guess how these will play out, especially as the plans are to increase the plant’s capacity to 400 MLD—a 100 per cent increase from the capacity cleared now. Another desalination plant of 200 MLD capacity has been planned in Versova.
In Manori, locals have been protesting hard against the imminent destruction to ecology and their lives. Already, 971 trees have been marked to be cut. Many in the city, having no idea of what the Manori Creek holds ecologically, see no reason why seawater should not be tapped into when other coastal cities like Chennai have done so. The BMC justifies the desalination plant on the grounds that the city’s shortfall of 500-600 MLD in potable or drinking water—Mumbai gets about 4,100 MLD, while the requirement is 4,664 MLD—will be made good to an extent.
Erratic supply, shortages in certain areas, and water cuts, like the 10 and 20 per cent cuts that the BMC imposed in May-June this year, further justify the need for any and all sources, such as desalination plants, irrespective of their financial outlay and ecological costs. Everyone seems pleased. Almost no one is asking the question: are the desalination plants really a requirement, or are they vanity projects?
The facts could not be clearer. First, by the civic body’s admission, nearly 35 per cent of the water leaks out of the supply system, while water policy experts put it at around 40 per cent. This comes to a whopping 1,435 to 1,640 MLD of water that should be in the network but is not. And it is seven to eight times the capacity of the 200 MLD desalination plant at Manori. Fix the leakages, dear BMC.
Second, Mumbai’s groundwater sources are rarely considered, but thousands of wells and borewells supply 6 to 8 per cent of the city’s water requirements, especially for non-domestic uses and construction sites. It has spawned a thriving private tanker economy. For some inexplicable reason, as water policy analysts like Sachin Tiwale point out, groundwater has not been calculated in Mumbai’s water sources and plans over the past 20 years.
Third, the BMC is investing a staggering Rs 26,000 crore to build seven wastewater treatment plants that, after secondary treatment, will supply 2,464 MLD for non-drinking purposes. This will be about half the water supply it now receives and releases as much potable water for distribution. If the treated water is put through tertiary treatment, it could even provide 1,232 MLD of water fit for drinking. These plants, the BMC projects, will be operational in 2027-28. This leaves no shortfall at all.
Fourth, the BMC is constructing the Gargai Dam in Palghar near the Tansa Wildlife Sanctuary to bring in 440 MLD in the coming years. This will augment the water now drawn from reservoirs and rivers that include the Bhatsa, Upper Vaitarna, Middle Vaitarna, Modak Sagar, Tansa, Vihar and Tulsi—most of them in the forests and hills far away from Mumbai.
Fifth, the underlying critical aspect is the fundamental calculation (or miscalculation) of the city’s water requirements. The Union government’s recommended benchmark for water supply in urban areas is 135 litres per capita per day (LPCD) and extends to 150-200 LPCD for large cities. Against this, Mumbai’s per capita per day needs were pegged at an inexplicable 240 LPCD in the Chitale Committee report of 1994; this has continued unexamined over the decades, as per Tiwale.
The Chitale Committee benchmark means over 1,000 to 1,200 litres a day for a household. The informal settlements that constitute over 45 per cent of Mumbai’s population hardly have the storage space for as much water. In fact, the BMC supplies barely 45 to 60 LPCD in most slums, according to the available data. Posh areas consume way more than even 240 LPCD. This, then, is an issue of equity in water supply across Mumbai, not a shortage in what it receives.
For decades, the 240 LPCD figure has been the basis for all calculations of how much water Mumbai needs—and to project shortfalls, which are then to be made good by water supply projects such as the Gargai Dam and the desalination plants. Why is the Union government’s benchmark of 135 to 200 LPCD not used as the basis instead? And why has groundwater not been taken into consideration?
Taken together, Mumbai has more water than it requires as a city; the existing available water needs to be distributed fairly and equitably. The city does not need to spend thousands of crores—and wreak havoc on ecology—to make plants that make more water for the city. It isn’t sensible, but then common sense and the larger public good have rarely informed infrastructure projects—especially for governments hell-bent on vanity projects.
Smruti Koppikar, an award-winning senior journalist and urban chronicler, writes extensively on cities, development, gender, and the media. She is the Founder Editor of the award-winning online journal ‘Question of Cities’ and can be reached at smruti@questionofcities.org.
