The outlet conduits of the sluice are about 66 m in length and are encased in a brick structure which is about 9.5 m wide and 2.84 m in height. Bricks of an exceptionally strong type had been used in the reservoir. Specimens of bricks from this part of the structure measure about 45.5 cm in length, 22.5 m in width and 6.5 cm in thickness.

An interesting and unusual element in the layout of the conduits is the incorporation of the so-called “wing wall”. This wall, built of a kiln–made brick, projects to the left of the path of the outlet conduits and extends along the line of the dam for about 10 m. It seems probable that the designers of the Maduru Oya sluice realized their construction, which had to withstand the effects of the passage of water at high pressure, needed, in addition to a good foundation, a means of securing its lateral stability.

The outer end of the sluice is formed of a stone block of massive proportions, which has been horizontally placed above three short stone pillars. The horizontal block is 2.5 m long and about 83 cm in width. The central pillar is of a similar cross-section, but the pillars on either side are each about 35 cm in width. Each of the two outlet orifices measures 70 by 95 cm. Though in general layout and appearance, the outlets are quite similar to those of sluice in other ancient reservoirs, there is one feature which is specific to the Madur Oya sluice. The brickwork to the north of the outlet had been carefully designed by a person who had a close acquaintance with the behavioural characteristics of fluids.

The builders of the Maduru Oya sluice laid a thin course of bricks over the stone roof of the rectangular outlet conduit. It is likely, they reasoned, that it was sufficient to prevent seepage under normal pressure. And if under exceptional circumstances, an unusual increase in pressure led to seepage, the thick brickwork forming the corbelled arch would have been meant to provide the second line of defence against seepage.

The structure represents a milestone / turning points in development of irrigated agriculture and bears an exceptional testimony to development of agriculture and increase in food production along with the improvement of economic condition of farmers;

Sri Lanka is well known for its ancient hydraulic civilization and major irrigation works constructed in the 3rd century AD. Some of these structures are often quoted as technically parallel to modern engineering designs and constructions. The ancient Maduru Oya sluiceway is one such structure as is coincidence with the same various site designed for the modem sluice under the recently executed Accelerated Mahaweli Development Project.  Compared with the remains of ancient sluices in Sri Lanka. The Maduru Oya ancient sluice possesses some salient features. One such feature is its twin inlet conduits, dressed in stone slabs enclosed in a massive, corbelled arch-shaped brickwork. Covering stone slabs with brickwork is a common construction pattern in ancient sluices, but this corbelled arch-shaped brick enclosure is only limited to Maduru Oya sluice.  The central pit forms special interest as its right wall has a peculiar terracotta design of dancers. A similar feature has not been located in any other sluice in Sri Lanka.

The Maduru Oya Sluice made up of stone slabs and bricks, is about 30 feet (9.1 m) high, 30 feet (9.1 m) wide and 219 feet (67 m) long. Professor Senarath Paranawithana believes that this sluiceway was built by King Kutakanna Tissa (42-20 BC). Carbon dating carried out in the USA has also placed the time period to 1st century BC. But the popular local belief is that the original dam here was built before the arrival of Vijaya by the Yaksha Tribes around the 6th century BC.

The structure contributed to the evolution of efficient and contemporary engineering theories and practices;

Sri Lanka is well known for its ancient hydraulic civilization and major irrigation works constructed in the 3rd century AD. Some of these structures are often quoted as technically parallel to modern engineering designs and constructions. The ancient Maduru Oya sluiceway is one such structure as is coincidence with the same various site designed for the modem sluice under the recently executed Accelerated Mahaweli Development Project.  Compared with the remains of ancient sluices in Sri Lanka. The Maduru Oya ancient sluice possesses some salient features. One such feature is its twin inlet conduits, dressed in stone slabs enclosed in a massive, corbelled arch-shaped brickwork. Covering stone slabs with brickwork is a common construction pattern in ancient sluices, but this corbelled arch-shaped brick enclosure is only limited to Maduru Oya sluice.  The central pit forms special interest as its right wall has a peculiar terracotta design of dancers. A similar feature has not been located in any other sluice in Sri Lanka.

The Maduru Oya Sluice made up of stone slabs and bricks, is about 30 feet (9.1 m) high, 30 feet (9.1 m) wide and 219 feet (67 m) long. Professor Senarath Paranawithana believes that this sluiceway was built by King Kutakanna Tissa (42-20 BC). Carbon dating carried out in the USA has also placed the time period to 1st century BC. But the popular local belief is that the original dam here was built before the arrival of Vijaya by the Yaksha Tribes around the 6th century BC.

The structure was unique in some positive and constructive way;

Sri Lanka is well known for its ancient hydraulic civilization and major irrigation works constructed in the 3rd century AD. Some of these structures are often quoted as technically parallel to modern engineering designs and constructions. The ancient Maduru Oya sluiceway is one such structure as is coincidence with the same various site designed for the modem sluice under the recently executed Accelerated Mahaweli Development Project.  Compared with the remains of ancient sluices in Sri Lanka. The Maduru Oya ancient sluice possesses some salient features. One such feature is its twin inlet conduits, dressed in stone slabs enclosed in a massive, corbelled arch-shaped brickwork. Covering stone slabs with brickwork is a common construction pattern in ancient sluices, but this corbelled arch-shaped brick enclosure is only limited to Maduru Oya sluice.  The central pit forms special interest as its right wall has a peculiar terracotta design of dancers. A similar feature has not been located in any other sluice in Sri Lanka.

The Maduru Oya Sluice made up of stone slabs and bricks, is about 30 feet (9.1 m) high, 30 feet (9.1 m) wide and 219 feet (67 m) long. Professor Senarath Paranawithana believes that this sluiceway was built by King Kutakanna Tissa (42-20 BC). Carbon dating carried out in the USA has also placed the time period to 1st century BC. But the popular local belief is that the original dam here was built before the arrival of Vijaya by the Yaksha Tribes around the 6th century BC.

The structure bears the stamp of a cultural tradition or a civilization of past;

Sri Lanka is well known for its ancient hydraulic civilization and major irrigation works constructed in the 3rd century AD. Some of these structures are often quoted as technically parallel to modern engineering designs and constructions. The ancient Maduru Oya sluiceway is one such structure as is coincidence with the same various site designed for the modem sluice under the recently executed Accelerated Mahaweli Development Project.  Compared with the remains of ancient sluices in Sri Lanka. The Maduru Oya ancient sluice possesses some salient features. One such feature is its twin inlet conduits, dressed in stone slabs enclosed in a massive, corbelled arch-shaped brickwork. Covering stone slabs with brickwork is a common construction pattern in ancient sluices, but this corbelled arch-shaped brick enclosure is only limited to Maduru Oya sluice.  The central pit forms special interest as its right wall has a peculiar terracotta design of dancers. A similar feature has not been located in any other sluice in Sri Lanka.

The Maduru Oya Sluice made up of stone slabs and bricks, is about 30 feet (9.1 m) high, 30 feet (9.1 m) wide and 219 feet (67 m) long. Professor Senarath Paranawithana believes that this sluiceway was built by King Kutakanna Tissa (42-20 BC). Carbon dating carried out in the USA has also placed the time period to 1st century BC. But the popular local belief is that the original dam here was built before the arrival of Vijaya by the Yaksha Tribes around the 6th century BC.

Engineering utility vis-à-vis designed utility

Maduruoya main dam is located across the Maduruoya between two inselbergs known as Kandegama and Danagala, located at about 77 km from the river mouth. This was the first of the main river reservoir projects to be completed under the accelerated Mahaweli project with the intention of providing irrigation waters to the Mahaweli system B area to cultivate about 42,000 ha of paddy lands (28,000 ha from the Left Bank and 14,000 ha from Right Bank outlets). This reservoir has a hydropower generation capacity of 7.5 MW.

At Present, Maduruoya Reservoir has provided livelihood to a large number of inhabitants. There are many people who benefitted from various employments such as paddy cultivation, cultivation of other field crops, inland fish industry, ornamental fish production, home gardening and Hydropower generation. The Maduruoya National Park is considered a major feeding area of the reservoir. The tourism field is also highly benefited as the National Park is around the Maduruoya Reservoir.

Present State of Conservation

Maduruoya Ancient Dam and the Sluice is preserved as an archaeological site.