About Thisaa wewa
Tissa Wewa is an ancient irrigation tank was built by King Devanampiya Tissa (250-210 BC). Only Panda Wewa and Abhaya Wewa are considered to be older than Tissa Wewa. The embankment of Tissa Wewa is 11,000 feet long (Two miles) and 25 feet high. The width of the top of the reservoir was found to be 12 feet to 18 feet. Base of the embankment is 160 feet. Tissa Wewa has an area of approximately 550 acres.
Mahawansa reports that King Bhatikabaya (20 BC-9 AC) pumped water using a machine up to Ruwanweli Seya and sprayed water to flowers which covered the full stupa. Further, water from this reservoir was also used to fill the tanks of Ranmasu Uyana, the Royal water garden next to the Isurumuniya Viharaya.
Tissa Wewa receives water through the ancient canal of Jaya Ganga, an ancient canal originating at Kala Wewa. The excess water is released to the Malwathu Oya river. The embankment of the Tissa Wewa tank is approximately 3 km long.