Diyawanna Lake

Diyawanna Oya Wetland, also known as Diyawanna Lake (දියවන්නා ඔය), is an urban wetland located about 11 km away from Colombo in Sri Jayewardenepura Kotte, the administrative capital of Sri Lanka. It is one of the most important marshlands that contribute towards water retention and flood protection in the Colombo Metropolitan Region (Thibbotuwawa et al., 2010). The Parliament of Sri Lanka is also located on a small island in Diyawanna Oya within this wetland system.

The Diyawanna wetland comprises vast marshlands, wooded areas and the flowing Diyawanna Oya and spreads over Sri Jayewardenepura Kotte and Kaduwela Municipal Council administrative boundaries (Ruzaik, 2021; Thibbotuwawa et al., 2010). The marshlands are connected to Diyawanna Lake, which is part of the Diyawanna Oya stream and is drained by Kirulapone Canal via. Dehiwala and Wellawatta Canal to the sea (Ruzaik, 2021). The wetland area receives an average annual rainfall of 2,427.8 mm and a temperature ranges between 31 °C and 24 °C (Ruzaik, 2021).

The wetland serves as a major recreational ground for exercise, sports, bathing and family outings for the surrounding dwellers as well as visitors from outside (Marawila & Thibbotuwawa, 2010). The inhabitants in surrounding areas use the wetland as a source of income from fishing, cattle grazing, collecting reeds, rushes and fuel wood (Marawila & Thibbotuwawa, 2010; Thibbotuwawa et al., 2010). It also provides important hydrological services and it is a rich habitat of endogenous fauna and flora (Thibbotuwawa et al., 2010). As a result, the Department of Wildlife has declared Diyawanna Oya as a Wildlife Sanctuary in 1984 in terms of the Fauna and Flora Protection Ordinance [(section No 1 of 1994,) Ruzaik, 2021].