IIT-G flags groundwater risks in Kamakhya Project, recommends strict depth limits

Guwahati, Feb 24: Depth-related precautions identified by the National Institute of Hydrology (NIH) should be strictly adhered during construction of the Maa Kamakhya Access Corridor Project to avoid disturbance to the critical fracture-controlled groundwater pathways, IIT Guwahati has recommended.

Following two petitions in the Gauhati High Court, the government had roped in Roorkee-based NIH to conduct detailed geophysical and hydrological survey on the possible impact of the Rs 500-crore Kamakhya corridor project. The NIH report was vetted by IITG.

“The analysis of the proposed construction layout, when superimposed on the mapped fracture systems, indicates the presence of interconnected fractures at depths ranging from 1.9 m to 10.5 m along the stretch between the upstream of Maa Kamakhya Temple and in front of Chinnamasta Temple, and between 3.9 m and 8.1 m within the Siddheshwar Temple premises,” the report stated.

“Accordingly, the foundation in the section from Maa Kamakhya Temple to Chinnamasta Temple should not exceed 1.9 m, while in front of Siddheshwar Temple, foundation should be restricted to 3.9 m or actual depth of the nearest fracture, whichever is shallower. Compliance with these limits is essential to prevent any disruption to the natural subsurface flow regime,” it further added.

In the playground area, the subsurface consists of approximately 3.2-3.5 m of soil-fill composed of coarse-grained sand, pebbles, and clay, underlain by compacted or weathered rock.

Fractures are observed at depths of 6.4-7.6 m, with geophysical data indicating a transition from soil-fill to weathered rock and then to hard rock.

IITG has recommended that foundation depths in this area should be limited to a maximum of 6.4 m, ensuring that construction activities do not intersect or disturb the fracture-controlled groundwater pathways.

“These recommendations are critical to safeguarding the integrity of the natural hydro-geological system while enabling the planned development to proceed responsibly,” the researchers stated.

Based on the recommendations, the project consultant has prepared fresh drawings, keeping the foundation depth to the restricted limits in all four blocks.

The PWD had told the Gauhati High Court that after detailed study of the area, it was “consciously decided to broadly locate all the proposed pilgrim facilities and utility buildings over the footprint of existing houses and structures, with the intent to use the ground which was compacted over many decades.”

On February 12, the Gauhati High Court had given its go-ahead to the PWD to execute the project after it assured that the precautions recommended by the research institutes will be adhered to.

The Rs 500-crore project is being planned is an area of around 15,000 square metres atop the Nilachal Hills to provide a state-of-the-art access to the one of the most revered shrines in the country thronged by lakhs of devotees every year.

The project comprises five components, including the three-level corridor from the parking to the temple entrance covering a length of around 350 metres.