A cycle track being built by the Municipal Corporation of Greater Mumbai on the periphery of the city’s Powai Lake has attracted a great deal of criticism from citizens for its potentially adverse environmental impact. In response, the municipal corporation has provided a number of justifications for the project in a recent press release.

The primary, “positive” justification is that the cycle track is required as a much-needed community space that is open to all, it said. But the project is a planning concern, especially given its environmentally-sensitive location. The central question is: why this, here?

This question has not been addressed by the authorities. Instead, the legalistic and technological justifications offered divert debate from this central question.

I write as an urban planning researcher who believes in two things of immediate relevance: one, the urgent need to conserve sensitive environmental resources and systems in Mumbai and other cities; two, the necessity of improving Mumbai’s livability.

The first belief is foundational to a variety of commitments we have made as a nation, from the commitment to protect wetlands under the Ramsar Convention, to the Sustainable Development Goals of the United Nations. Another belief forms the background of analysis: the centrality of social justice and equity in urban planning.

In general, I also believe that ambiguity about the legal or policy status of an environment like Powai Lake does not exempt anyone impacting it from the moral responsibility of accounting for its realities. Excess water from a cloudburst, or the unforeseeable damage from lost biodiversity, are real forces that do not generally submit to the logic of policy definitions.

Responsible planning: The ‘community space’ argument

The municipal corporation clearly believes that the cycle track is necessary for improved livability. Though it has not spelt out an argument clearly, it can be inferred from its press release. It has two parts: a tacit premise and a conclusion.

The premise is that Mumbai lacks public spaces. The premise appears to be generic to the city since the municipal corporation has not justified the project as a response to a real local need.

The conclusion that seems to have been derived from this premise, however, is specific: therefore, we need to build a cycle track around Powai Lake. The problem is that there is no argument connecting the generic premise to the specific conclusion. It is like a roof without any walls to hold it up – it cannot remain in place even if the foundation is solid.

Like most Mumbaikars, I agree with the municipal corporation’s generic premise. The shortage of public open spaces is clearly a city-wide problem. A city-wide problem demands, to begin with, a city-wide analysis and strategy. A rational analysis would involve empirical studies of sizes, geographic distribution, accessibility, usability, environmental sensitivity of public spaces open to all Mumbaikars (like this one from a few years ago).

This could yield a range and hierarchy of intervention options in different places, ranked in relation to the way they maximise the quantity, quality and distribution of benefits for the minimum social, economic, and environmental costs.

Without such a city-level strategy, an intervention in an environmentally sensitive location can only be considered arbitrary.

The natural ecosystem around Powai lake stands degraded. Photo: Packerworld at English Wikipedia, CC BY-SA 3.0

Precautionary principle

Had a systematic analysis of the problem of a lack of public space in Mumbai, or even locally, been conducted, I believe that it would not have led to the conclusion that a cycle track must be built at Powai Lake. That is because any such analysis and the resulting intervention strategy would have to stand on the precautionary principle: first, do no harm.

This principle applies to situations where we simply don’t know enough either about the problem or the solution to be able to judge the damage that unintended outcomes could cause. This is a principle adopted internationally by legal bodies in matters of environmental management where there exists scientific uncertainty.

Intervention in a sensitive ecosystem – even if it is man-made, like Powai Lake – is one such situation. In particular, the land-water interface, where the cycle track is located, is a highly productive site, ecologically speaking. Assuming that municipal corporation has not conducted any study of the environmental sensitivity of the project site and its surroundings – for instance, about the biodiversity it supports – it is likely that it did not know enough about the impacts of this specific project before undertaking it.

This belief is reinforced by the recent announcement that a committee of experts has been constituted to examine and help mitigate the project’s environmental impact after the project is underway.

In general, of course, environmental systems are inadequately understood and so are the effects of urban interventions on them, as well as on the city in the future. All we know scientifically, in general, is that the effect is very likely to be significant in the short, and the long term.

If, however, we do have some indicators that damage to a particular environment could have bad outcomes in the future, the precautionary principle must dominate in decision making.


Let us now turn to implementation. There is little doubt that Powai Lake is at the centre of a valuable natural ecosystem that has become degraded. This is why the municipal corporation had initiated the Powai Lake Rejuvenation and Beautification Mission a few years ago.

Phase 1 of this mission had components such as sewage interception and diversion, sewage treatment and hyacinth removal. The cycle track project forms Phase 2.

Phase 1 is clearly the more important undertaking, but needs more intensive effort. There is little reason to jump directly to Phase 2. In fact, as environmentalists have argued before, the priority ought to be prevention rather than cure: preventing sewage flowing into the lake. That is, understandably, a serious challenge. But that is no reason to divert institutional resources towards building something that is more likely to damage the lake ecosystem further than improve it.

The municipal authorities have not been able to prevent sewage flowing into the Powai Lake. Photo: Shyam Saksena

The municipal corporation has argued that the gabion wall it plans is a sustainable technological solution. It is heartening that the municipal body has considered the damage that building the cycle track conventionally would cause. However, only detailed hydrological modelling can help us conclude that this technology will not affect surface runoff into the lake significantly – there is no evidence that such modelling has been done.

Of course, the municipal corporation makes no claim that the wall will not affect stormwater runoff into the lake at all – only that the gaps in the mortarless pile of stones in this technology will allow more water to flow than a fully solid wall. We can thus expect flooding upstream from the lake to increase, rather than decrease, as a result of the cycle track.

Apart from flooding, the loss of biodiversity is an important concern. The construction of the cycle track is already disturbing the local ecosystem and will impact biodiversity. For instance, there are crocodile nesting places which are likely to be affected by construction activity even if it does not use too much cement or concrete

Once complete and under use, the cycle track is likely to increase solid waste and noise pollution, both of which can also reduce biodiversity. The much smaller lakeside promenade along the Jogeshwari-Vikhroli Link Road (officially known as Adi Shankaracharya Marg) is already poorly maintained, and offers little confidence that the 10 km track can be maintained to avoid such pollution.

No better? Then, no worse please

Some things are perhaps beyond debate. The cycle track is certainly not going to improve the ecosystem or environmental services offered by Powai Lake either because of its planning or implementation logic. In fact, it is more likely to damage both. Only scientific studies prior to conceiving the project could have helped identify and prevent significant damage and there is no evidence of these having been undertaken.

Expert recommendations for mitigation of a poorly conceived project can only hope to make the best of what was originally a bad deal. The project, thus, appears to go against common sense, environmental logic, and sustainable-planning rationality. Especially, if we agree that the city’s livability should, and can, be improved without compromising its environmental performance and resilience.

Himanshu Burte is an Associate Professor at the Centre for Urban Science and Engineering, Indian Institute of Technology, Bombay. The author’s views are personal and do not represent those of IIT Bombay.