Rambakan Oya Dam

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Rambakan Oya Dam
Rambakan Oya.jpg
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Location of Rambakan Oya Dam in Sri Lanka
Country Sri Lanka
Location Maha Oya
Coordinates 7°27′4.85″N81°24′20.47″E / 7.4513472°N 81.4056861°E / 7.4513472; 81.4056861 Coordinates: 7°27′4.85″N81°24′20.47″E / 7.4513472°N 81.4056861°E / 7.4513472; 81.4056861
Purpose Irrigation and Domestic water supply
Status Operational
Construction began 12 February 2007
Opening date 20 July 2013
Owner(s) Ministry of Irrigation
Dam and spillways
Type of dam Earthen dam
Height 24.7 m (81 ft)
Length 1,225 m (4,019 ft)
Width (crest) 7 m (23 ft)
Spillways 2
Spillway type Radial Gate
Spillway capacity 554.75 m3/s (19,591 cu ft/s)
Creates Rambakan Oya Reservoir
Total capacity 56,000,000 m3 (2.0×109 cu ft)
Catchment area 129.5 km2 (50.0 sq mi)

The Rambakan Oya Dam is an embankment dam in Maha Oya, Eastern Province, Sri Lanka. The reservoir was designed and constructed by the Sri Lanka Mahaveli Authority and currently functions under the direction of the Ministry of Irrigation and Water Resources Management. [1] It have been created by building an Earthen dam of which is about 1225m in length across the river of Mundeni Aru. [2]

Embankment dam large artificial dam

An embankment dam is a large artificial dam. It is typically created by the placement and compaction of a complex semi-plastic mound of various compositions of soil, sand, clay, or rock. It has a semi-pervious waterproof natural covering for its surface and a dense, impervious core. This makes such a dam impervious to surface or seepage erosion. Such a dam is composed of fragmented independent material particles. The friction and interaction of particles binds the particles together into a stable mass rather than by the use of a cementing substance.

Maha Oya

The Maha Oya is a major stream in the Sabaragamuwa Province of Sri Lanka. It measures approximately 134 km (83 mi) in length. It runs across four provinces and five districts. Maha Oya has 14 Water supply networks to serve the need of water and more than 1 million people live by the river.

Eastern Province, Sri Lanka Province in Sri Lanka

The Eastern Province is one of the nine provinces of Sri Lanka, the first level administrative division of the country. The provinces have existed since the 19th century but did not have any legal status until 1987 when the 13th Amendment to the Constitution of Sri Lanka established provincial councils. Between 1988 and 2006 the province was temporarily merged with the Northern Province to form the North Eastern Province. The capital of the province is Trincomalee.


The Rambakan Oya reservoir project is a multipurpose irrigation project which is commissioned to find a solution for the drinking water issue and irrigation problems in the area. [3] It is the 10th zone of Mahaweli Development scheme and located bordering Badulla, Monaragala and Ampara districts. [4]

The Mahaweli Development programme is known as the largest multipurpose national development programme in the history of Sri Lanka and is also considered as the keystone of the government's development programme that was initiated in 1961.

Badulla City in Sri Lanka

Badulla is the main city of Uva Province situated in the lower central hills of Sri Lanka. It is the capital city of Uva Province and the Badulla District.

Monaragala Town in Uva Province, Sri Lanka

Monaragala is a town located in Monaragala District, Uva Province, Sri Lanka. It is the largest town in Monaragala District and is located 57.3 km (35.6 mi) northwest of Badulla, the capital city of Uva Province. The town of Monaragala is situated about 151 m (495 ft) above sea level on the Colombo-Batticaloa main road.


Ancient time

There are archaeological evidences, those reveals about previous attempts to construct an irrigation tank here during the ancient time periods. [5] According to them there are different legends and archaeological views on ancient construction of Rambakan Oya Reservoir. It is believed that construction of Rambaken Oya Reservoir was commenced by prince Giri Abaya who ruled the East, in third century, B.C. According to some other historical evidences it was commenced by Prince Saddhatissa (137-119 BC).

Saddha Tissa was a monarch of the Kingdom of Anuradhapura, based at the ancient capital of Anuradhapura from 137 BC to 119 BC. Saddha Tissa was the son of Kavan Tissa of Ruhuna and the brother of Dutthagamani. He was the ruler of Digamadulla, the present day eastern province of Sri Lanka.


This nearby structure is believed to be made for the sluice gate of the tank RambakenOya Ruins.jpg
This nearby structure is believed to be made for the sluice gate of the tank

There is a one-mile longed old earthen dam can be seen, near to the newly constructed dam. It was constructed between Gorikanda and Galkanda with rip rap, in high quality. Around 250 feet long dressed stones made to use for the twin Barrel Sluice are still remaining in surrounding. Any way there is no evidence to prove that the construction was completed or the reservoir was functioned.

Near to the old Sluice, a stone slab inscription belonging to 12th – 13th centuries can be seen and which identified as Rambakan Oya Slab Inscription. It describes that the stone canal was built by Liyana Nayakayan and Kanathkan Vahanse, who lived in the Gal Weta area. [6]

Sluice A water channel controlled at its head by a gate

A sluice is a water channel controlled at its head by a gate. A mill race, leet, flume, penstock or lade is a sluice channelling water toward a water mill. The terms sluice, sluice gate, knife gate, and slide gate are used interchangeably in the water and wastewater control industry.

Recent project

The recent project to develop the Rambakan Oya reservoir was commenced on 12 February 2007 [7] and the opening ceremony was held on 20 July 2013 with the participation of then Sri Lanka President Mahinda Rajapaksa and Irrigation and Water Resources Management Minister. [8]

Mahinda Rajapaksa Prime Minister of Sri Lanka

Percy Mahendra Rajapaksa is a Sri Lankan politician serving as Leader of the Opposition since 2018, and has served as Member of Parliament (MP) for Kurunegala since 2015. He served as the President of Sri Lanka and Leader of the Sri Lanka Freedom Party from 2005 to 2015.

See also

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  1. "Rambukkan Oya Reservoir". development.lk. 22 July 2013. Retrieved 10 November 2015.
  2. "Rambukkan Oya". Irrigation Departmaent. Retrieved 10 November 2015.
  3. "Rambaken Oya reservoir built with local expertise, commissioned". asiansun.lk. Retrieved 10 November 2015.
  4. "Rambaken Oya Project". news.lk. 6 October 2011. Retrieved 10 November 2015.
  5. "Rambakanoya Tank-Rambakan Oya Old Construction". srilankatravelnotes.com. Retrieved 10 November 2015.
  6. "Rambakan Oya Ruins of Ancient Granite Canal – අම්පාර රඹකැන් ඔය ගල් ඇල". amazinglanka.com. Retrieved 10 November 2015.
  7. Naalir Jamaldeen (21 July 2013). "Rambakan Oya irrigation project commissioned". sundayobserver.lk. Retrieved 10 November 2015.
  8. "Rambakan Oya Multipurpose Irrigation Project:'Landmark in country's irrigation history'". dailynews.lk. 2 July 2013. Retrieved 10 November 2015.