Step 1: Understanding the Concept:
The question asks for the location of the first operational hydroelectric power plant in India.
Step 2: Detailed Explanation:
\[\begin{array}{rl} \bullet & \text{The first hydroelectric power plant in India was the Sidrapong Hydroelectric Power Station.} \\ \bullet & \text{It was commissioned in 1897.} \\ \bullet & \text{The power plant is located near Darjeeling in the state of West Bengal.} \\ \bullet & \text{It was established to supply electricity to the city of Darjeeling.} \\ \end{array}\]
Step 3: Final Answer:
The first hydropower plant in India was established in Darjeeling.