Colombo, May 15 : Sri Lanka's Irrigation Department has warned of possible floods in some areas in the country's south as the water level of a major river has increased following heavy rains. The department said on Sunday in a statement that a considerable rainfall had occurred in some of the upstream and middle reach catchment areas of the river called Gin Ganga, Xinhua news agency reported. By analysing the current rainfall situation and river water levels at hydrological stations in Gin Ganga, a considerable flood possibility is likely to occur in low-lying areas of the Gin Ganga valley, the Irrigation Department added. Residents in those areas and vehicle drivers driving through there have been advised to pay high attention to the situation. Sri Lanka's Department of Meteorology said on Sunday that the showery condition is expected to continue further in southern parts of the country due to the indirect influence of the extremely severe cyclonic storm Mocha in the Bay of Bengal. Heavy showers above 100mm are likely to occur at some places in Southern province and Ratnapura district, and residents have been urged to take adequate precautions to minimise damage caused by temporary strong winds and lightning during thundershowers locally. /IANS