25-05-2025
BMC launches aquifer mapping project along Mithi river to enhance water supply resources
Eyeing to enhance Mumbai's water supply resources, the Brihanmumbai Municipal Corporation (BMC) has launched a pilot project along the Mithi river basin to carry out a geophysical study and mapping of groundwater levels to determine its quality and quantity. Slated to be conducted over the course of one year, the project will undertake aquifer mapping with the aim of developing new public recharge systems like borewells.
The study is in line with the National Aquifer Mapping and Management (NAQUIM) programme by the Central Ground Water Board, which was initiated by the Jal Shakti Ministry in 2012 to prepare the area specific groundwater management plans. While the CGWB has been conducting its own mapping across the country over the past two years, the BMC's pilot project is an independent study, being carried out by its environment and climate change department.
The mapping project, according to officials, is aimed at making Mumbai's existing water resources future proof in the wake of the climate crisis.
Currently, Mumbai draws its potable water from seven lakes, situated in Mumbai as well as neighbouring districts like Thane, Palghar and Nashik. It is during the four monsoon months that these lakes are replenished, with the water from their catchment area supplied across the city throughout the year through a complex network of water channels.
'Mumbai presently is entirely dependent on the surface level water with all its resources and lakes situated far away from the city.
However, in light of the climate change crisis, if Mumbai were not to receive adequate rain for two years, it can face the brunt of severe water scarcity. To establish new means of resources in a coastal city like Mumbai, we will have to tap into the groundwater levels for which we will need to conduct a study by digging the surface and examine the salinity of underground water, considering Mumbai's proximity to the coasts,' said an official.
With the aim of identifying appropriate zones to develop new public recharge systems, the civic body has now taken up the cudgels to conduct mapping and study of aquifer levels beneath the surface. This is the first time that the civic body is conducting such a study, officials said.
For its pilot project, the BMC will commence the study along the Mithi river basin as it serves as the biggest natural catchment area in Mumbai and passes through Sanjay Gandhi National Park.
Speaking to The Indian Express, an official said the project will first look at the geophysical survey to determine the geology and make-up of the soil. 'Following this, we will carry out a geochemical survey wherein we will conduct sampling of the soil, rock and water quality. Then, we will do thematic mapping through which we will determine the confined and unconfined zone. On the basis of our mapping, we can plan the appropriate means of a recharge structure,' the official added.
Recently, the BMC floated tenders for the supply of equipment for the collection of data for the aquifer mapping project. Pegged to cost over Rs 25 lakh, equipment such as 300 water quality testing kits, manual rain gauge, GPS devices, measuring tapes of upto 30 m lengths, water level loggers and sounders will be procured to conduct the pilot mapping work.
Meanwhile, the civic body has already started identifying borewells and ringwells along the Mithi river, wherein the study will be carried out. Spanning 17.8 km, the Mithi river originates at Vihar Lake and flows through several zones encompassing slum areas, industrial pockets as well residential zones, before it discharges into Mahim creek.
'If our pilot project along Mithi succeeds, we will try to replicate the project across the rest of the city. Ultimately, our objective with the project is to strengthen Mumbai's water supply resources,' said the official.
