The drainage canal which collects the excess rain water from Chidambaram Natarajar temple &drains it in a pond north of temple is an engineering marvel built by Cholas.The 10th century canal takes water from a lower level to the pond which is at a higher level. How it was done ? 
The canal expands & contracts at specific intervals and also bends like a snake at many places. This sort of structure acts like an ‘electric pump’ which takes water against its natural flow. The 1250m canal was built with bricks with the top covered by granite.
It must be noted that a similar canal was built during Parantaka Chola’s time to take water from Kollidam river to the Veeranam lake against its flow & then to Walaja lake which is at 70 KM distance.This shows that such structures are widely used during that time for irrigation
