Anawilundawa Sanctuary

Anawilundawa Sanctuary
Anawilundawa Sanctuary
Anawilundawa Sanctuary
Coordinates: 7°42′N 79°49′E / 7.700°N 79.817°E / 7.700; 79.817
LocationAnawilundawa, Sri Lanka
Part ofPuttalam District
Area
 • Total1,397 hectares (3,450 acres)
Official nameAnnaiwilundawa Tanks Sanctuary
Designated3 August 2001
Reference no.1078[1]

Anawilundawa Sanctuary, also known as the Annaiwilundawa Tanks Sanctuary, is located in the west of Sri Lanka in the Puttalam District, internationally important wintering ground for migratory water birds in Sri Lanka. This site covers an area of 1,397 ha (3,450 acres).[1] The region was designated as a wildlife sanctuary by the Department of Wildlife Conservation on 11 June 1997 under the Fauna and Flora Protection Ordinance. On 3 August 2001, it was selected as the second Ramsar wetland in Sri Lanka after Bundala National Park.[2]

The area is renowned for rich biodiversity, cultural heritage and sustenance of local livelihood. The wetland is serving as a major feeding ground for migratory birds and home for unique blend of endemic and native flora and fauna.[1][3]

Location and boundaries

Anawilundawa Sanctuary is located between the coast and the Negombo-Puttalam railway. Chilaw town is 10 km to the south, and Puttalam town is located 35 km to the north. It is demarcated by the Udappuwa–Battuluoya road in the north, the Chilaw–Puttalam railway in the east, the Sengal Oya in the south, and the Dutch canal in the west.[4]

Geography

The wetland consists of group of shallow cascading tanks, ranging from 12 to 50 ha in extent, built around 1140 AD by King Parakramabahu the Great. There are seven small irrigation tanks in the wetland which comprise 188 hectares: Pin kattiya, Wellawala, Maradansole, Ihala Wewa, Anawilundawa, Suruwila and Maiyawa. All the tanks are similar in depth, where no one exceeding a depth of 4m at the deepest point closer to the tank bund. To the west of the tanks is a large area of paddy fields with an area of 412 ha are located to the west of the tanks with islets of natural vegetation. In the same direction, there is a canal, constructed by the Dutch. This canal joins the Mundel Lake in the north, and Deduru Oya and Sengal Oya estuaries in the south.[4]

The surrounding land is filled with surface run-off water from Rathambala Oya basin with a catchment of 215 square km, and spillwater from the Katupotha tank. Excess water is flowing into the Sengal Oya via Dutch canal and through the outlet in Maiyawa tank.[4]

Climate

Anawilundawa Sanctuary is located in the dry zone of Sri Lanka, therefore has a hot climate mostly throughout the year. The mean annual temperature is about 26 degrees Celsius and the humidity touches 80% at the beginning of December. Annual rainfall is about 1000mm to 1500mm where the wetland mainly receives rainfall during the northeast monsoon. The soil type is generally reddish brown earth and sparsely filled with sand dunes, clay and silt. The rock are known to be Precambrian crystalline rocks.[4]

Livelihood of people

According to the researches done by several universities, there are about 2,500 families living in and around the Anawilundawa Sanctuary. About 90% of them depend on paddy cultivation, based on irrigation water from the tanks. Other employments include subsistence fishery in the tanks, coconut cultivation, coastal fishing, and prawn farming as well as some engage in tourism.[4]

Biodiversity

The World Conservation Union, undertook a biodiversity assessment in 2003.[4] Several local and foreign experts carried out numerous researches on flora and fauna in the area. The wetland comprised with three major ecosystems: the freshwater wetland, saltwater wetland and terrestrial ecosystems. The seasonally inundated habitat on tank fringes are covered with forest patches, scrublands, short grasslands and marshes, which gives various breeding habitats for animals.[5]

A total of 290 plant species belong to 95 families, were recorded from Anawilundawa wetland. The endemic plant Vernonia zeylanica and two nationally threatened species Aponogeton natans and Diospyros ebenum are found in the area. Other than that, there are 60 introduced species recorded in the area. The tanks are covered with 24 aquatic plant species including rare mangrove species Xylocarpus granatum. In the terrestrial forests, there are 120 woody tree species, 61 shrub species, 49 herbaceous species, 34 species of climbers and 2 epiphytes species.[5]

The vertebrates fauna of the wetland include 47 species of fish, 11 species of amphibians, 34 species of reptiles, 168 species of birds, and 21 species of mammals. Besides, the wetland is home to Invertebrates which includes 78 species of butterflies, 13 species of dragonflies and damselflies and 6 species of aquatic molluscs.[5] The wetland is home to 37 species of migrant birds and 4 introduced fish species.[6][7]

Anawilundawa Assisted Natural Regeneration of Mangroves (ANRM) Project has inaugurated in 2020 by The Department of Wildlife Conservation (DWC) in 2020, signed an MoU with the Wildlife and Nature Protection Society (WNPS) of Sri Lanka to conserve mangroves in the wetland.[8][9]

Threats

The tanks are highly infested with invasive species. There are nine invasive alien plants in the area, where Eichhornia crassipes and Salvinia molesta are the major invasive species. Other than that, the wetland is influenced by habitat loss, degradation and modification, direct use and over-exploitation of species such as illegal prawn farming.[5][10][11][12][3][13]

Species recorded

Amphibians

Chelonians

Geckoes

Lizards

Snakes

Mammals

Butterflies

Birds

See also

References

  1. ^ a b c "Annaiwilundawa Tanks Sanctuary". Ramsar Sites Information Service. Retrieved 5 April 2025.
  2. ^ "Anawilundawa wetland sanctuary". lovesrilanka.org. 13 November 2025. Retrieved 13 November 2025.
  3. ^ a b "Spotlight on devastation to environment at Anawilundawa". dailymirror.lk. 13 November 2025. Retrieved 13 November 2025.
  4. ^ a b c d e f "A preliminary survey on the herpetofauna in the Anawilundawa wetland sanctuary: The second Ramsar site of Sri Lanka". researchgate.net. 13 November 2025. Retrieved 13 November 2025.
  5. ^ a b c d "A Biodiversity Status Profile of Anawilundawa Sanctuary: A Ramsar Wetland in the Western Dry Zone of Sri Lanka". researchgate.net. 13 November 2025. Retrieved 13 November 2025.
  6. ^ "Anawilundawa Bird Sanctuary Sri Lanka". bestoflanka.com. 13 November 2025. Retrieved 13 November 2025.
  7. ^ "Anawilundawa Bird Sanctuary Sri Lanka". srilankaecotourism.lk. 13 November 2025. Retrieved 13 November 2025.
  8. ^ "Saving Anawilundawa". ceylontoday.lk. 13 November 2025. Retrieved 13 November 2025.
  9. ^ "A second chance for mangroves". sundaytimes.lk. 13 November 2025. Retrieved 13 November 2025.
  10. ^ "Wetlands again ravaged for illegal prawn farming". sundaytimes.lk. 13 November 2025. Retrieved 13 November 2025.
  11. ^ "Farming throughout the year triggers collapse of Anawilundawa Ramsar wetland ecosystem". sundaytimes.lk. 13 November 2025. Retrieved 13 November 2025.
  12. ^ "Anawilundawa wetlands under threat". srilankaecotourism.lk. 13 November 2025. Retrieved 13 November 2025.
  13. ^ "Anawilundawa ANRM Project: Where people, nature thrive hand in hand with mangroves". wnpssl.org. 13 November 2025. Retrieved 13 November 2025.