Kala Wewa, built by the King Datusena in 460 CE, is a reservoir complex consisting of two reservoirs, Kala Wewa and Balalu Wewa. It has the capacity to store 123 million cubic meters of water. This reservoir complex has facilitated with a stone made spillway and three main sluices. From the central major sluice, a 40 feet wide central conveys water to feed thousands of acres of paddy lands and ends at the historical capital Anuradhapura city tank Tissa Wewa meandering over 87 km (54 mi) at a slope of 6 inches per mile and is another wonder of primeval hydraulic engineering facility in ancient Ceylon.