Significant rainfall have been recorded over the past 24 hours causing water levels in the upper catchment areas of the Mahaweli, Kelani and Kalu rivers to rise rapidly, according to the Department of Irrigation.

Director of Hydrology and Disaster Management (Irrigation Department), Engineer L.S. Sooriyabandara, said the heavy rainfall had led to a noticeable increase in river water levels, prompting authorities to issue flood alerts for vulnerable areas.  

Nearly 200 mm of rainfall, with some locations exceeding that amount, was recorded in the upper Mahaweli basin, including Nawalapitiya, Nanu Oya and Watawala. As a result, residents living along the Mahaweli River between Nawalapitiya and Peradeniya have been advised to remain alert for possible flooding.

Although water levels are currently showing only a gradual increase rather than a rapid surge, the Irrigation Department has issued precautionary warnings.

Officials said the present situation is not expected to escalate to the scale of the floods experienced during Cyclone Ditwah, noting that the current rise was mainly due to more than 70 mm of rainfall recorded in some areas overnight.

In the upper Kelani River basin, including Laxapana, Norwood and surrounding areas, rainfall between 100 mm and 150 mm was recorded. Water levels have risen in upstream areas such as Kitulgala, although they have since begun to recede.  

However, there remains a risk of flooding in low-lying areas, particularly between Hanwella and Avissawella, as well as in areas between Avissawella, Kitulgala and Norwood. While river levels are not increasing rapidly, officials warned that downstream sections of the Kelani River could experience further rises.

Meanwhile, nearly 100 mm of rainfall was recorded in the upper Ratnapura area, pushing water levels close to the warning level. Although no significant increase has been observed, low-lying areas remain at risk of inundation.

The Department also reported that rivers in the wet zone, including the Nilwala and Gin rivers, received between 50 mm and 75 mm of rainfall. However, these rivers are not currently expected to reach flood levels.

In contrast, the Maha Oya and Attanagalu Oya catchments recorded relatively low rainfall, and no flood threat has been identified for those areas at present.