Kala Wewa and Yodha Ela (Jaya Ganga) – An irrigation wonder of Ancient Sinhalese
This reservoir has a circumference of over 40 miles (65 km) and has a total area of 7 square miles ( 18.1 square kilometers) at full capacity. The ancient spill (pitawana) is measured to be 216 feet (66 meters) in width and 170 ft (52 meters) in length. For comparison, the width of the spill is more than three quarters length of a soccer field! The spill was built using hammered Granite, a solid structure one could imagine. Each block of Granite is shaped precisely to fit its neighbor. The whole structure eventually acts like one huge rock.
Once the Kala Wewa was completed, he built an another tank called Balalu wewa adjoining Kala Wewa and joined the two, creating one of the largest tanks in the history. Therefore sometimes this massive irrigation reservoir is called Kala Balalu Wewa. The total length of the dam is 22,572 feet (6,879.9 m) and the height is 40-60 feet (12-18.3 m).
Yodha Ela, a 87 kilometer canal was then built to bring water from Kala Wewa to the city of Anuradhapura. All the three major reservoirs in the city of Anuradhapura (Abhaya wewa, Tissa wewa and Nuwara wewa) and the Nachchaduwa reservoir was fed by the Yodha Ela.
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.
King Dhatusena’s Kalawewa – Jayaganga scheme was designed to provide water to sixty village reservoirs and to the city of Anuradhapura. Many irrigation Engineers are still baffled how a 40 feet wide, 87 km long canal with a such a precise slope could have been planned and constructed 1,500 years ago.
Many a features had been added to the canal since its construction. King Parakramabahu who governed the country nearly 700 years after the Yoda Wawa, reconstructed the canal added more feeders to the canal starting from thirty four reservoirs found between Kala Wawa and Thissa Wawa, re-naming it Jaya Ganga or the river of victory.
When the British discovered this tank they could not comprehend the need for a such a massive spill who didn’t understand the dynamics of monsoon rain in the region.
In his 1837 book “The Maháwanso in Roman Characters: With the Translation Subjoined – and an introductory essay .., Volume 1”, George Turnour writes
“This tank situated 20 miles north west of the temple of Dambulla on the road to Anuradhapura, and which has hitherto attracted little notice, exhibits perhaps the remains of one of the greatest of the ancient great works of Ceylon. The circumference of the area of the tank, when the embankment was perfect, could not be less than 40 miles. The embankment, with the lateral mound of the Balalu Wewa is at least 10-12 miles long. The stone spill water in the broken bank of Kala Wewa is perhaps, one of the most stupendous monuments in the island, of misapplied human labour. The canal by which the waters of this tank were conducted to Anuradhapura, may still be partially traced : and in this vicinity the remains of the ancient fortress of the Wijitha are to be found. ”
There are some folklore on how the king was able to find a place for the tank he wanted to build. There was a man called Kadawara who left his family and went to live in the jungle due to his wife’s harassment. After some years in the jungle he was well accustomed with wild animals and lived with a herd of deer. One day a hunter suddenly noticed this strange man living with animals in the jungle; went to the palace and told the king that it seems that this strange man lives in the forest in order to guard an unknown treasure there. King sent his army and Kadawara was brought before the king. The Kadawara revealed his story and and the king asked him of any interesting thing he had seen while living in the jungle. Kadawa said, “No sir, I have not seen anything interesting but in a brook somewhere in the jungle, water is being blocked by the flora called Kala that has been grown across that stream.
The king visited this place and realized that this was an ideal place for a reservoir and appointed Kadawara to over see the maintenance of the tank once it was completed. One rainy day Kadawara noticed a tiny leak on the embankment. While waiting for the repairmen to come, he noticed that the leak increasing and to stop further damage he is said to have stuck his head in to the leak saving the dam. He died of this incident and said to be born as a deity still looking after this tank
Even today you will see a Devale at Kala Wewa dedicated to Kadawara Deviyo, who still protect the Kala Wewa and the people in the area.
In addition to irrigating acres of paddy fields, Kala Wewa based eco system supports a large variety of wild life and elephants become a frequent sight during the dry season.
Close these tanks also lies Vijithapura Raja Maha Viharaya and the gigantic Alwukana Buddha Statue which is another work of King Dhatusena.
Legend say that king Dutugemunu built a temple embodying winning post which used to inform the victory over Elara and this temple is believed to be the Vijithapura Rajamaha Viharaya. Although there is no much historic evidence, the temple is littered with old ruins which are believed to be belonging to the Anuradhapura Era.
