The water levels of several main rivers are on the rise due to the prevailing heavy rainfall, warned the Disaster Management Center (DMC).Accordingly, the water level of the Kelani River has risen from Deraniyagala and the water level of the Kalu Ganga has risen at the Ratnapura area.Additionally, the water level of Ging Ganga has risen at the Thawalama area, stated DMC.The Disaster Management Center urges public residing downstream of these rivers to be vigilant