NEW DELHI: The Ministry of Environment, Forest and Climate Change (MoEFCC) has instructed the Central Water Commission (CWC) to provide recommendations on how to sustain environmental flows in the Chambal River during the lean season, ensuring that conservation efforts related to the Ganges River dolphin are not adversely affected.
Concerns arose following the initiation of a series of dam constructions under the East Rajasthan Canal Project (ERCP) over the tributaries of the Chambal River, including the Banas, Kuno, Parbati, and Kalisindh rivers in Madhya Pradesh and Rajasthan. Moreover, no environmental impact assessment has been conducted to evaluate how the project will affect dolphin conservation and potentially affect other aquatic life.
A senior officer stated, “The project will draw water from the tributaries of the Chambal River, threatening its environmental flows.” Furthermore, evaporation during the summer months is expected to result in additional water loss.
According to a study by the Wildlife Institute of India (WII), dolphins require a minimum depth of three metres in flowing rivers to survive during lean seasons. The officer emphasised, “So far, no environmental assessment has been done to determine how these projects will impact dolphins, gharials, and other aquatic species.”
The WII study highlighted that the decreasing flow of the Chambal River has been affecting dolphin movement. During the lean season, dolphins tend to concentrate in the deeper pools of the river.
Field data analysed
The WII’s study analysed field data on the distribution of Ganges River dolphins, gharials (crocodilian species with long, thin snouts), and other important aquatic life, including turtles. It also assessed water depth, water quality, and seasonal river flow patterns, along with 10-day flow data from CWC
The study found that during the lean season, dolphins were largely confined to deep pools, indicating that reduced river flows significantly affect habitat availability for aquatic species.
The findings underscored the importance of maintaining adequate environmental flows in the Chambal River to support aquatic biodiversity and ecological integrity.
During recent discussions at the National Wildlife Board meeting, it was noted that the issue involves aspects of river flow regulation and water management, which fall under the CWC's mandate. The Ministry of Environment, Forest and Climate Change has determined that a comprehensive examination by the CWC is necessary.
The Ganges River dolphin and gharial serve as reliable indicator species for assessing the health of the Ganga River ecosystem.