The Irrigation Department has issued a minor flood warning for low-lying areas along the Mahaweli River, saying a minor flood situation could develop within the next 24 hours.
The warning names seven Divisional Secretariat divisions: Udunuwara, Udapalatha, Yatinuwara, Doluwa, Ganga Ihala Korale, Gangawata Korale and Harispattuwa.
The department cited two reasons — forecasts of further rainfall over the Mahaweli’s upper catchment, and the recent opening of spill gates at the Kotmale Reservoir.
Residents living near the river in those divisions have been urged to stay vigilant and take precautions. Disaster management authorities have been asked to take proactive measures, and the public advised to monitor conditions as more rain is expected.
A step down from the Red alert
The notice replaces a considerably more severe warning that expired the same day. The Irrigation Department’s Red major-flood alert — issued at 1.00 p.m. on Monday for 48 hours across ten divisions — ran out at 1.00 p.m. on Wednesday.
Three divisions covered by that emergency notice are not in Wednesday’s warning: Kotmale, Pasbage Korale and Pathadumbara. The remaining seven carry over at the lower minor-flood tier.
Kotmale’s removal is notable given that the reservoir is cited as a trigger for the new warning. Its spill gates were reopened at about 7.00 a.m. on Wednesday, releasing roughly 130 cubic feet per second into the Mahaweli — a far smaller discharge than Monday’s release, which was followed by flooding around Gampola and the displacement of about 500 families.
More rain due
The easing is unlikely to hold. The Met Department expects falls above 100 mm at some places in the Kandy and Nuwara Eliya districts on Thursday as the southwest monsoon strengthens — the same upper catchment that feeds Kotmale and the divisions named in this warning.
Update (August 6): flood risk subsided
The Irrigation Department said on Thursday that the minor flood risk affecting low-lying areas along the Mahaweli River has subsided.
The Mahaweli Authority reported that water levels in several major reservoirs are gradually declining. Director General H.M.J.K. Herath said rainfall over the Kotmale catchment had eased slightly compared with previous days, and that efforts were under way to hold the Kotmale Reservoir’s storage between 90 and 95 percent. Around 100 cubic metres per second is being released from Kotmale for hydroelectric generation, allowing the national grid to draw more than 200 megawatts at full output.
Water levels at the Victoria Reservoir have continued to rise on inflows from the Polgolla diversion and from the Kotmale and Gampola areas, pushing its storage above 50 percent.
Landslide warnings remain in force for divisions in the Kandy, Kegalle, Nuwara Eliya and Ratnapura districts, and the Met Department expects the monsoon to intensify over the coming days.
Sources: Ada Derana, Daily Mirror, NewsFirst.
