A community based initiative in Sri Lanka to keep our natural environment clean

Thalangama Wetland Watch

The Thalangama Area


Examples of waste removed from various locations of the Thalangama Environmental Protection Area
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Located just a few kilometers away from Colombo, the Thalangama (Talangama) wetlands are an environmental protection area and biodiversity hotspot in a rapidly urbanizing environment. It is the perfect spot for a relaxing afternoon in nature and for those who are passionate about birding.

The wetland is home to two man-built reservoirs (tanks) namely Thalangama tank and Averihena tank, both just 300 meter apart. The Thalangama tank spanning about 28 acres (11 ha) is comparatively larger and much older than the recently constructed Averihena tank (8 acres or 3.2 ha) and serves today mainly as a source of irrigation water supply for about 100 acres (40 ha); maintained by the Department of Irrigation. The tanks are also important for floodwater retention and have a high scenic and aesthetic value, which attracts many visitors. They are particularly rich in biodiversity with a remarkable Avifauna (bird population), which is well-known among local and foreign wildlife enthusiasts. The wetland is also in high demand for educational purposes, fishing, biking, bathing and the collection of flowers and water lily leaves for ceremonial purposes. Both tanks thus constitute multi-purpose urban freshwater resources with different stakeholder interests that govern its use and management. The three graphics in this section show how the local residents value the lake and paddy fields and what they see as major problems based on a survey of 145 local residents.

Due to rapid urbanization of the area, the land value has increased significantly leading to excessive land filling and the reclamation of paddy lands for housing, despite the fact that this activity is illegal. This is accompanied by indiscriminate (over-night) garbage and construction waste disposal, next to the volume of litter and bottles left by the daily lake visitors. Given the overall garbage challenges in the country, authorities are struggling with a way to address these issues. In our area, the Thalangama Wetland Watch is providing the community service to keep the lake and their surroundings as clean as possible. This service also includes the removal of invasive plants, in particular water hyacinths from the lake surface and the support of a balanced open water – vegetation cover to allow water circulation (see About us and our work).

What local residents value as purpose of the paddy fields in percent of answers (Molden, 2011)

What local residents value as purpose of the lake area in percent of answers (Molden, 2011)

What local residents see as negative activities in the Thalangama lake area in percent of answers from 145 local residents (Molden, 2011)


Molden, O. 2011. Sociological report on Thalangama community in relation to the Thalangama tank and wetlands. Whitman College, USA. Environmental Sociology Thesis Report.