The Brihanmumbai Municipal Corporation (BMC) has commenced soil investigation for the proposed 52-million litres per day (MLD) reservoir project at Malabar Hill. This marks a significant step in the civic body's plan to develop an alternative to the aging underground water reservoir while attempting to preserve the iconic Hanging Gardens situated above it.
Geotechnical Investigation Underway
Civic officials stated that the geotechnical investigation will help determine the nature of the rock strata, soil stability, foundation depth, and structural feasibility of the proposed elevated reservoir structures. “Currently, borehole drilling and subsurface testing are being carried out across multiple locations within the proposed reservoir site and adjoining utility areas. This is like an X-ray of the ground. We need to understand the type of rock, soil stability and depth before finalising the structural design,” an official explained.
Design and Approval Process
A civic official noted, “We will need approval from the executive body once the design is finalised. Thereafter, work at the site will begin. Notices regarding the 76 trees likely to be impacted will also be issued later this year.” According to engineers, approximately one borehole is planned for every 100 square metres at the tank site, apart from separate investigations near valve chambers and utility sections, which will be carried out in the coming months. Some boreholes are expected to extend nearly 20 metres below ground level to study subsurface conditions.
Officials said that the detailed engineering design, currently underway, will include foundation design, structural layout, column positioning, and an assessment of load-bearing capacity.
Garden on Top of Reservoir
The BMC is also planning a 2,200 square metre garden atop the proposed ground-plus-two-storey alternate tank structure. However, officials emphasized that any garden developed above the reservoir would require tree species whose root systems do not penetrate deeply into the masonry and water-retaining structure. They indicated that the proposed garden would attempt to create a “level match” with the elevated Hanging Gardens adjacent to it, so that the area’s existing landscape character can be retained as far as possible.
Historical Context
The Malabar Hill reservoir, one of Mumbai’s oldest water infrastructure assets, dates back to the British era and is located beneath Hanging Gardens. The new project aims to provide a modern alternative while preserving the heritage and greenery of the area.
