Brohier (1965) states, that it verily baffles understanding of how a canal of this magnitude could have been planned and executed over such a difficult terrain nearly 1500 years ago. This canal, also known as Jaya-ganga, meanders over the first 17 miles at an unbelievable gradient of no more than 7 inches to a mile. Thereafter it is led in deep gorges across saddles between water- sheds.
The gradient of Yodha Ela was measured to be 6 inches per mile. (1:10,000). Maintaining such a gradient is an extremely challenging task even for the modern engineers who have access to laser guided survey equipment. Few miles after leaving Kalawewa, the Jayaganga divides into two branches. One branch goes towards Nachchaduwa reservoir while the other goes towards the Anuradhapura city reservoirs.