Sri Lankan authorities issued parallel landslide and flood warnings on Friday morning as the south-west monsoon established over the island, with the Department of Meteorology forecasting rainfall exceeding 200mm in some areas.
The National Building Research Organisation (NBRO) issued landslide early warnings for five Divisional Secretariat Divisions across three districts, valid until 3.00am on Saturday 23 May. Amber-level (Warning Level 2) alerts cover Attanagalla in the Gampaha district and Ratnapura and Kuruwita in the Ratnapura district. Yellow-level (Warning Level 1) alerts cover Bulathsinhala in the Kalutara district and Eheliyagoda in the Ratnapura district.
The Irrigation Department separately issued a flood warning for low-lying areas in the Aththanagalu Oya and Uruwal Oya basins after heavy rainfall in most catchment areas as of 5.00am. The warning, valid for 48 hours, covers nine Divisional Secretariat divisions in Gampaha district: Diwulapitiya, Mirigama, Attanagalla, Mahara, Gampaha, Minuwangoda, Ja-Ela, Katana and Wattala. The department said roads in low-lying areas could be inundated and urged motorists to remain vigilant.
The Met Department’s morning bulletin said the south-west monsoon was “gradually establishing” over the island. Very heavy rainfall above 200mm was forecast for parts of the Western, Sabaragamuwa and North-Western provinces, with rainfall above 100mm also likely in the Galle, Matara, Kandy and Nuwara Eliya districts. Fairly strong winds of 35–45 km/h are expected over the western slopes of the central hills and across the Northern, North-Central, North-Western and Southern provinces, as well as the Trincomalee district.
By mid-morning the NBRO had escalated the alert to its highest tier. A 6.00am bulletin upgraded two Divisional Secretariat divisions — Dehiowita in Kegalle and Ratnapura in Ratnapura — to Level 3 (Red — Evacuate), the agency’s most severe landslide warning. Amber Level 2 alerts were simultaneously broadened to cover Seethawaka and Padukka in Colombo, Ingiriya in Kalutara, Ruwanwella in Kegalle and Pelmadulla and Ayagama in Ratnapura, in addition to the divisions already on alert. Yellow Level 1 warnings were added for Yatiyantota in Kegalle, Ambagamuwa in Nuwara Eliya, and Nivitigala and Kalawana in Ratnapura. The Red warning advises immediate evacuation from at-risk locations and remains in force until 6.00pm on Saturday 23 May.
The escalation comes hours after the Met Department’s overnight Amber advisory for rainfall above 100mm in eight districts, with the latest forecast doubling the upper rainfall threshold and adding formal landslide and flood-zone alerts.
Pre-monsoon flood-control preparations were discussed earlier this week at a meeting chaired by President Anura Kumara Dissanayake, focused on Kelani River basin defences. The south-west monsoon onset was confirmed by the Met Department on 19 May.
Sources: Ada Derana, Ada Derana, Newswire, Ada Derana.
