Guwahati: The Indian Institute of Technology Guwahati(IIT-G) has recommended strict adherence to depth-related construction precautions identified by the National Institute of Hydrology (NIH) during the execution of the Maa Kamakhya Access Corridor Project.
The institute warned that failure to follow these limits could disturb critical fracture-controlled groundwater pathways in the Nilachal Hills.
Earlier, following two petitions filed before the Gauhati High Court, the Assam government engaged the Roorkee-based NIH to conduct a detailed geophysical and hydrological study. The survey assessed the potential impact of the ?500-crore Kamakhya corridor project on the area’s fragile subsurface system. Subsequently, IIT Guwahati vetted the NIH findings and endorsed its recommendations.
According to the report, researchers superimposed the proposed construction layout on the mapped fracture systems. As a result, they identified interconnected fractures at depths ranging from 1.9 metres to 10.5 metres along the stretch between the upstream of the Maa Kamakhya Temple and the area in front of the Chinnamasta Temple.
In addition, the study detected fractures between depths of 3.9 metres and 8.1 metres within the premises of the Siddheshwar Temple.
Based on these findings, the report advised that foundation depth between Maa Kamakhya Temple and Chinnamasta Temple should not exceed 1.9 metres.
Likewise, construction in front of the Siddheshwar Temple should restrict foundation depth to 3.9 metres or to the actual depth of the nearest fracture, whichever is shallower. Importantly, the researchers stressed that strict compliance is essential to prevent disruption of the natural subsurface groundwater flow regime.
Meanwhile, in the playground area, investigators observed a subsurface layer of approximately 3.2 to 3.5 metres of soil-fill comprising coarse sand, pebbles and clay. This layer rests over compacted or weathered rock. Fractures in this zone appear at depths between 6.4 metres and 7.6 metres, with geophysical data indicating a transition from soil-fill to weathered rock and eventually to hard rock.
In response, IIT Guwahati recommended that foundation depth in the playground area be capped at a maximum of 6.4 metres. This restriction, the institute noted, would ensure that construction activities do not intersect or disturb fracture-controlled groundwater pathways.
“These recommendations are critical to safeguarding the integrity of the natural hydro-geological system while allowing the planned development to proceed responsibly,” the researchers stated.
Acting on the advice, the project consultant has prepared revised drawings. The updated plans limit foundation depths across all four blocks in line with the prescribed thresholds.
Earlier, the Public Works Department (PWD) informed the Gauhati High Court that it had consciously decided to locate most pilgrim facilities and utility buildings over the footprints of existing houses and structures. The department said it adopted this approach to use land compacted over several decades and minimise geological disturbance.
On February 12, the Gauhati High Court allowed the PWD to proceed with the project after authorities assured that they would strictly follow all safeguards recommended by the research institutions.
The ?500-crore Maa Kamakhya Access Corridor Project, planned over nearly 15,000 square metres atop the Nilachal Hills, aims to provide state-of-the-art access to one of India’s most revered shrines. The temple draws lakhs of devotees every year. The project includes five components, most notably a three-level corridor spanning about 350 metres from the parking area to the temple entrance.