First desilting planned for TN's largest reservoir Mettur dam, may cost Rs 3,000 crore

CHENNAI: In a first move 90 years after the Stanley Reservoir was built in Mettur, the State Water Resources Department (WRD) has taken measures to desilt and deepen the State's largest dam, as part of the initiative to deepen water bodies across the State to increase storage.

The initiative aims to restore its full storage capacity which currently stands at 224.47 thousand million cubic feet (tmc).

As part of this effort, the department has issued a tender for a project management consultancy to prepare a detailed project report (DPR) for desilting and deepening reservoirs across the State including the one in Mettur.

A senior WRD official told DT Next that the department had recently issued an order to hire a consultancy to assist the government in obtaining statutory approvals from various agencies, including clearance from the Union Ministry of Environment, Forest, and Climate Change. "We will engage the agency to explore the possibilities of desilting the reservoirs and prepare a DPR. It should also help the department secure all necessary approvals from statutory bodies," said the senior bureaucrat. The government has allocated Rs 3 crore for the consultancy.

The consultancy will also assist the department in addressing environmental issues associated with sediment management practices in the reservoirs in a holistic and comprehensive manner, according to another official in the department.

The total storage capacity of the state's 90 reservoirs is 224.297 tmc. Among them, the Mettur Reservoir tops it with a capacity of 93.470 tmc, followed by Vaigai (60.91 tmc). Apart from these reservoirs, Amaravathy (40.47 tmc) and Pechiparai (43.50 tmc) will also be taken up for desilting, according to the official.

Sources in the department said that sedimentation over time has reduced the storage capacity of most of the state's reservoirs. "The department prepared a feasibility report last year in collaboration with Water and Power Consultancy Services Limited (WAPCOS) after inspecting Mettur, Vaigai, and several other reservoirs. We have estimated that desilting Mettur Reservoir alone will cost Rs 3,000 crore," the official added.