Southwest monsoon gradually sets in; Heavy rainfall expected from Tuesday

The southwest monsoon is likely to establish over Sri Lanka around May 26 or 27, bringing increased rainfall to the southwestern parts of the island during that period, the Department of Meteorology has stated.

Meanwhile, data from the Irrigation Department indicates that water levels in several major rivers, which rose following heavy rainfall in recent days, are now gradually returning to normal levels.

With the gradual establishment of the southwest monsoon over the island, many areas in the southwestern region experienced heavy showers over the past few days. Some areas recorded rainfall exceeding 200 mm to 300 mm, causing water levels in several major rivers to rise and triggering flood situations.

However, due to the absence of heavy rainfall yesterday (23), river water levels have begun to recede to normal conditions.

The Irrigation Department’s report issued at 9:30 a.m. today (24) stated that the water level of the Kelani River has now returned to normal.

Nevertheless, a minor flood situation continues in the Millakanda area along the Kalu River. The water level of the Kuda River, a tributary of the Kalu River, was recorded at 6.51 metres at the Millakanda gauge station as of 8:00 a.m. today (24).
Ada Derana reporter stated that although the water level is gradually decreasing, it still remains above spill level.

Low-lying areas around Ballapitiya in Horana also remain inundated. In addition, traffic along the Bulathsinhala–Kalutara road continues to be disrupted due to flooding in the Diyakaduwa area.

Authorities further noted that water levels of the Kalu River in the Putupawula and Ellagawa areas remain at levels requiring close attention.

Meanwhile, the water level of the Attanagalu Oya, which had risen in recent days, is also gradually receding. However, the Irrigation Department has advised residents in the Dunamale area to remain vigilant.

Several houses along Paris Perera Mawatha and the Suduwella area in Ja-Ela remain submerged due to overflow from the Attanagalu Oya.

Residents allege that flooding has worsened because the canal embankment at the beginning of Paris Perera Mawatha, which was damaged during Cyclone Ditiwah late last year, has still not been repaired.

Amid the prevailing conditions, the Swarna Hansa Podi Ela bridge in Ja-Ela collapsed yesterday (23) evening.

The main bus route from Ja-Ela to Gampaha also remains flooded in the Yakkaduwa area.

Furthermore, the Disaster Management Centre (DMC) stated that 28,933 persons from 7,482 families in eight districts, including Ratnapura, Gampaha and Kalutara, have been affected by the adverse weather conditions.

Additionally, 1,731 individuals from 491 families are currently being sheltered at 18 safe locations. The DMC also reported 836 partially damaged houses and two fully damaged houses due to the disaster situation.

Commenting on the weather forecast for today, tomorrow and the coming days, Meteorologist Kasun Pasqual of the Department of Meteorology stated:

“Weather conditions today and tomorrow are expected to remain fairly similar to normal conditions. However, we expect an increase in rainfall over the southwestern parts of Sri Lanka on May 26, 27 and 28. Around those dates, we are likely to officially declare the establishment of the southwest monsoon over the island.”