At a time when Mumbai is experiencing extreme climate events like heat wave and relentless waterlogging during the monsoon, the Brihanmumbai Municipal Corporation (BMC) administration has floated a proposal to carry out a survey and identify the number of natural lakes in the city that still exist.

The move comes at a time when Mumbai witnesses a series of redevelopment and infrastructure work. As a result, many natural water bodies, including lakes and ponds, have been either reclaimed or filled to make land available for development leading to loss of ecological biodiversity. According to experts, the natural lakes play a key role in micro climate moderation by lowering the temperature in urban areas, mitigating the urban heat island effect.

Some of the key lakes that exist in Mumbai include the Tulsi lake, Vihar lake, Powai lake, Sion Talao, Bandra Talao, Mahim Talao and Banganga Tank. Of these, the Tulsi and Vihar lakes supply potable water to Mumbai daily.

“The overall drive will be a multi stage drive. In the first stage, we will identify the locations in our own city plan where natural water bodies are marked. Then we will carry out a survey to identify the present condition of these water bodies. If they still exist, then they will be rejuvenated and developed into blue zones of Mumbai,” Avinash Dhakane, additional municipal commissioner told the Indian Express.

He said the primary objective behind this project is to find the lost lakes and ensure that the effects of urban heat are mitigated along with ecological sustainability. Dhakane also maintained that the larger plan is to upscale the city’s overall urban infrastructure by rejuvenation of these water bodies to make open spaces more accessible for people.

“At present, the project is in the planning stage. Once we develop the entire modus-operandi, the project proposal will be drafted following which a tender will be floated to appoint consultants for this project,” he added.

The lost lakes of Mumbai

Meanwhile civic officials said that in Mumbai’s Development Plan (DP) 1991 and 2034, there were 300 lakes likely in Mumbai. However, in the last three decades due to various infrastructure and real estate projects, several lakes were reclaimed and filled by the authorities.

According to a survey report carried out by the World Wide Fund for Nature (WWF), 129 sites were identified via satellite imagery as potential sites for natural lakes in Mumbai. However, the survey stated that natural lakes could only be found in 68 locations, while 17 locations stayed inaccessible. It also stated that several areas were found to be dug up and used as foundation pits where construction work had begun when the survey had started.

“Earlier Mumbai used to have several natural water bodies in every pocket and till the middle of the 20th century people were largely dependent on these lakes for their daily sources of water as pipelines hadn’t reached many places in the suburbs. However after the real estate boom began during the 1980s, many of these lakes were filled.

Also, many of these lakes were labelled as potential breeding spots for mosquitoes and were reclaimed to prevent the spread of malaria,” an official said.

Environmental advantage

Experts maintained if natural lakes are identified and rejuvenated, it will help mitigate flooding in Mumbai.

“Lakes serve as heat sinks, moderating the temperature levels of the space where they are located. At present, the overall temperature of Mumbai has seen a rise largely due to urban heat effects of concreting work. The lakes will be able to control them,” Dr Shashank Joshi, a hydrological expert and researcher told Express.

“Lakes are also a crucial ecosystem and act as natural water cycle regulators. They act as sponges absorbing excess rainfall water, preventing overflow of rain water and also act as water catchments, thus avoiding water logging during the dry weather period,” Joshi added.