Explanation: The Idukki dam is a significant hydroelectric project located in the Idukki district of Kerala, India. It is one of the largest arch dams in Asia and is constructed across the Periyar river. The Periyar river is the longest river in Kerala and flows through the districts of Idukki, Ernakulam, and Thrissur. The dam is a crucial source of hydroelectric power for the state of Kerala and plays a vital role in the region's energy supply.
The construction of the Idukki dam was completed in 1975, and it has since been a landmark in Kerala's infrastructure. The dam is part of a larger hydroelectric project that includes the Idukki reservoir and the Idukki Power Station. The reservoir created by the dam has a capacity of 204,000 acre-feet and is used for both power generation and irrigation purposes.
The Periyar river, across which the Idukki dam is constructed, is a major river in Kerala. It originates in the Anamalai Hills and flows through several districts before draining into the Arabian Sea. The river is known for its scenic beauty and is an important source of water for the region. The construction of the Idukki dam has had a significant impact on the river's flow and the surrounding ecosystem.
It is important to note that the Periyar river is distinct from other major rivers in Kerala, such as the Meenachil, Pamba, and Bharathapuzha rivers. The Meenachil river is a tributary of the Periyar river and flows through Kottayam and Idukki districts. The Pamba river flows through Pathanamthitta and Alappuzha districts, while the Bharathapuzha river, also known as the Nila river, flows through Palakkad and Thrissur districts.
Understanding the specific river associated with the Idukki dam is crucial for students studying the geography and hydroelectric projects of Kerala. The Periyar river is the correct river across which the Idukki dam is constructed, making option C the correct answer.