Which was the first reservoir in the world?

The first known reservoir in the world is believed to be the Jayalalitha Reservoir, also known as the Kallanai Dam, located in Tamil Nadu, India. Constructed around the 2nd century AD during the rule of the Chola dynasty, it was designed for irrigation purposes to manage the water flow of the Kaveri River. This ancient engineering marvel demonstrates early advancements in water management and agricultural practices.