Bolgoda, presumed to be the largest natural fresh water lake in Sri Lanka, covers almost two thirds of the Kalutara District, extending from Anguruwatota to Piliyandala. The extent of the lake is approximately 374 square kilometers, its main source of water is through a Dutch feeder water way from the Kalu Ganga in the Kalutara District and the catchment from the surrounding areas and marshes. Its depth is said to range from 20-50 feet.

The Bolgoda lake system is situated in the low country wet zone of Sri Lanka. This system is made up of two interconnected lakes and their waterways. The North Lake, parts of which belongs to both Colombo and Kalutara Districts, is the largest. It is fed by Weras Ganga and Bolgoda Ganga which brings water from the South Lake. It discharges to the sea through the Panadura estuary. The South Lake is situated in the Kalutara District and is fed by the Panape Ela. It is connected to the sea via Thalpitiya Ela.

Climate

The Lake area receives an annual rainfall of about 2569.3mm and the main annual temperature is around 27.1C. The rainfall is more or less evenly distributed throughout the year. However, in the months of May and October there are two peaks, when most of the surrounding area become seasonal swamps. These provide the fish, seasonal breeders in particular, with a spawning area filled with allochthonous foods. Mean day relative humidity is around 72% and the mean night relative humidity is 87%. Mean wind speed is 8.3km/h (at 0830h) and 11.4 km/h (at 1730h). Effective temperature of the area is 24.6C.

Fishing and the lake life

The pristine beauty of this lake is preserved by the few people living off its rich resources. There are days when you will be the only one on the lake. The life of those living off the lake begins with the faun and flora in and around this beautiful body of water. Most of the inhabitants living on the banks of Bolgoda are fishermen, who use the canoe (Oru), nets and hand linesto fish. The species of fish caught are the Mangrove Jack, Barramundi, Ox-eyed Herring and a few other small varieties of fish. There are others who have constructed prawn traps called “JaKottuwas” across most of the lake. There is a sport fishing done on the lake, targeting the Barramundi and Mangrove Jack. A few sport fishermen are seen fishing in this lake.

The bird life around the lake is a bird watchers paradise. The Jacana, Purple Coot, Gray & Purple Heron, flocks of Whistling Teal, Grebes, the Brahminy kites and the beautiful white bellied Fishing Eagle are seen soaring the skies. These waters are also home to the masters of the lake… the Crocodiles!