NEW DELHI: Decreasing water depth in the upper reaches of the Chambal River is leading dolphin populations to shift their hotspot downstream, toward the confluence with the Yamuna River. Further, lowering of the water level during the lean season exposes nests belonging to the endangered river fauna at river islands to threats from jackals, stray dogs, and cattle.
These concerns were highlighted in a report from the Wildlife Institute of India, which was prepared to address the conservation of the iconic dolphin species in light of the ongoing reduction in the flow of the Chambal River.
Titled “Ecological Assessment of the Chambal River: Status of Major Aquatic Fauna and Flow Requirements”, the report was submitted at the recent meeting of the Standing Committee of the National Board for Wildlife under the Ministry of Environment, Forest, and Climate Change (MoEFCC) on March 21.
The report underlined a drastic reduction in the river’s flow, attributing this decline to increased water usage from the river’s tributaries. The report indicated that the river is under high stress, posing a serious risk to its ecological biodiversity. It noted that upstream flow has been restricted by the Gandhi Sagar Dam, Rana Pratap Sagar Dam, Jawahar Sagar Dam, and the Kota Barrage, warning that any further extraction could lead to complete drying of downstream areas.
The study analysed water flow data from the past three decades, showing a consistent decline. In 1990, the water flow was approximately 75 cubic meters per second (cumsec), which drastically reduced to 25 cumsec in 2022 during the lean season.
Meanwhile, the flow is normal during the monsoon; however, it remains highly fluctuating. The decline in river flow has impacted the movement patterns of dolphins, leading to observed shifts in their distribution downstream. This change affects the breeding opportunities of various species.
This newspaper had first reported that MoEFCC has requested that the Central Water Commission assist in increasing river water flow during the lean season to aid dolphin conservation. Dolphins require more than 3m to survive.