The Department of Irrigation has issued a flood warning for low-lying areas along the Mahaweli River, saying several are at risk of flooding within the next 24 hours after heavy rainfall in the river’s upper catchment.

The warning was issued at 12.30 a.m. on Monday (3) and runs until 12.30 a.m. on Tuesday (4).

It applies specifically to low-lying land associated with the Mahaweli in six Divisional Secretariat divisions, all in the Kandy district:

Residents living in low-lying areas and close to the river have been urged to stay vigilant and take precautions to protect themselves and their property. The department has also asked disaster management authorities to take immediate preparedness and response measures where necessary, and warned the public to stay alert to changes in weather and river conditions with further rain expected in the coming days.

Falling on ground already under warning

Two of the six divisions named — Pasbage Korale and Ganga Ihala Korale — are simultaneously under second-level landslide alerts. The National Building Research Organisation issued landslide early warnings at 11.00 p.m. on Sunday for divisions across Kandy, Kegalle, Nuwara Eliya and Ratnapura, valid until 11.00 p.m. on Monday.

The Met Department’s Monday forecast expects rainfall above 100 mm at some places in Sabaragamuwa and in the Kandy and Nuwara Eliya districts — the Mahaweli’s upper catchment, and double the threshold forecast for Sunday.

A river already running high

The warning is the third escalation on the Mahaweli in as many days. On Saturday the river burst its banks at Peradeniya and Nawalapitiya, submerging a bridge repair site and flooding sixteen houses. On Sunday two spill gates at the Polgolla dam were opened two feet each, releasing 3,940 cubic feet of water per second into the Victoria Reservoir.

Gangawata Korale contains Kandy town itself, and Udunuwara, Yatinuwara and Udapalatha lie immediately around it — the stretch of valley directly downstream of Polgolla.

Separately, the Irrigation Department has maintained a minor flood warning for the Kelani River basin, where spill gates at the Canyon Reservoir were opened on Saturday.

Update (August 3, midday): students evacuated at Peradeniya, alert for Gelioya

The University of Peradeniya has evacuated students from the ground floor of its “Sarasavi Medura” hostel as the Mahaweli continues to rise, Hiru News reported. The university administration ordered the move immediately in view of the risk from continued heavy rainfall, and issued a general notice telling students in other hostels and elsewhere on the campus to stay alert.

Vice Chancellor Professor Terrence Madhujith issued a separate advisory urging students housed along the Mahaweli basin to exercise extreme caution, Ada Derana reported.

The bridge repair site at the Peradeniya “Kalu Paalama” has already been inundated by the rising river. Several pieces of heavy machinery at the site are submerged, and some equipment and construction materials have been swept downstream by the current — the second time in three days that the same repair site has gone under.

The Disaster Management Centre has urged people living in Gelioya town and in university buildings near the river to remain vigilant against sudden flooding, the Daily Mirror reported, saying water levels in the Mahaweli and nearby waterways have risen significantly. Both Gelioya and Peradeniya sit inside the stretch of the Kandy district already covered by Monday’s warning.

The Irrigation Department said water levels are climbing rapidly in the Kalu, Kelani and Mahaweli rivers, with significant rises recorded at Ratnapura on the Kalu, Kitulgala on the Kelani and Peradeniya on the Mahaweli, NewsFirst reported. The heaviest rainfall in the 24 hours to Monday was recorded in the Nuwara Eliya district at 127 mm.

Update (August 3, 1.00 p.m.): Red major-flood alert, ten divisions, 48 hours

The Irrigation Department has escalated the warning, saying there is a severe risk of a major flood developing on the Mahaweli within the next 48 hours because of the heavy rainfall over the river’s upper catchment and the risk that spill gates at the Kotmale Reservoir will have to be opened.

The Red emergency notice — numbered 01 — was issued at 1.00 p.m. on Monday and runs until 1.00 p.m. on Wednesday, August 5, Hiru News reported. It is a substantially wider and longer warning than the amber notice it replaces: ten Divisional Secretariat divisions instead of six, and 48 hours instead of 24.

The divisions now covered are:

Doluwa, Kotmale, Harispattuwa and Pathadumbara are the four additions. Kotmale’s inclusion is the significant one: it places the division immediately below the Upper Kotmale Reservoir inside the flood warning at the same time as the department cites that reservoir’s spill gates as a reason for the escalation. Three of its gates opened automatically in the early hours of Monday, and engineers said the remainder could follow if catchment rain continued.

The department has asked people living in low-lying land near the Mahaweli in the listed divisions to watch conditions closely and take all precautions against possible flooding.

Update (August 3, afternoon): Peradeniya suspends all academic activity

The University of Peradeniya has suspended all academic activities and examinations until further notice, the Daily Mirror reported, extending Monday’s earlier hostel evacuation to the whole campus.

In a notice to students, the administration said the decision was taken for the safety of students and staff, and that essential campus services would continue. Students able to travel safely have been allowed to go home. Those who cannot may remain in university hostels — with the exception of the Sarasavi Medura hostel, evacuated earlier in the day — after informing hostel authorities. The university said no student would be forced to vacate accommodation.

Peradeniya has also offered space on campus to students living in private boarding houses in high-risk areas, and instructed hostel authorities to take them in and keep records.

The rain behind it

Rainfall exceeding 100 mm was recorded at a string of locations in the 24 hours to 6.00 a.m. on Monday, Hiru News reported, with the highest at Watawala in the Nuwara Eliya district at 204 mm — well above the 127 mm district figure cited earlier in the day.

Other stations above 100 mm were Norton 187.8 mm and Hunugalaoya 137.8 mm, Kotagala 137.0 mm, Nanu Oya 131.6 mm and Hatton 148.4 mm, all in Nuwara Eliya; Dolosbage 172.0 mm and Nawalapitiya 153.4 mm in Kandy; Kitulgala 140.8 mm in Kegalle; and Wewelwatta 112.4 mm and Walaboda 101.2 mm in Ratnapura.

Watawala, Norton, Kotagala and Hatton all lie in the Kotmale Oya and upper Mahaweli catchments feeding the reservoirs behind Monday’s warning.