Seven reservoirs were spilling across Sri Lanka on Monday and the Victoria Reservoir — the largest in the Mahaweli chain — is nearing its maximum capacity, the Irrigation Department said. By late afternoon the National Building Research Organisation had raised six areas of the Ratnapura district to a Level 3 landslide warning, the grade at which residents are told to leave.
The Department of Irrigation says several reservoirs are spilling because of continuing heavy rainfall, NewsFirst reported at 2.11 p.m.
Where the water is going
| Reservoir | Gates open | Discharging into |
|---|---|---|
| Polgolla (Mahaweli) | 2, opened Monday morning | Victoria Reservoir |
| Kukule Ganga | 2, opened early Monday | Kuda Ganga |
| Ibbankatuwa (Dambulla) | 1, opened Monday morning | Dambulu Oya → Kala Wewa, at 100 cusecs |
| Kala Wewa | 2, opened six inches each | — |
| Deduru Oya | all 8 remain open | Deduru Oya river |
| Rajanganaya | 8 | — |
| Thabbowa | 8 (four at two feet, four at one foot) | Mee Oya, at 2,640 cusecs |
The Thabbowa figures come from the Daily Mirror, which reported at 3.40 p.m. that 2,640 cubic feet of water per second is being released into the Mee Oya. Irrigation Department Director (Water Management) Eng. H.M.P.S.D. Herath said four spillway gates had been opened by two feet each and another four by one foot each to manage the inflow. Residents living downstream of the reservoir and along the banks of the Mee Oya were urged to watch for changes in river levels and to follow Irrigation Department and disaster management announcements.
That filing closes a gap this desk has recorded as open for several days. Earlier reservoir filings in this spell gave gate counts without a discharge rate or per-gate opening heights; Monday’s gives all three, together with a downstream advisory.
Rajanganaya is back to eight gates
The Rajanganaya figure is the one to watch, because it has now reversed twice.
The reservoir ran eight gates at its peak last week, came down to two on Sunday evening as the rain eased, reopened to six on Monday morning, and is now back to eight. An easing recorded in the morning did not hold through the afternoon.
A caution on reading these numbers: a gate count describes how the discharge is distributed, not how much water is moving. Deduru Oya was releasing 16,500 cusecs on 21 October and roughly 5,300 cusecs on 26 October — with eight gates open on both occasions. Thabbowa’s eight gates, opened to two different heights, make the same point within a single reservoir.
Victoria is filling
The most consequential line in Monday’s reporting is not a gate count. The engineer in charge of the Victoria Reservoir says it is nearing its maximum capacity, while Polgolla upstream is passing more water into it.
Victoria is the largest reservoir in the Mahaweli system and the country’s biggest hydroelectric store. The Irrigation Department issued a minor flood warning for the Mahaweli at 1.06 p.m. on Monday covering the Pasbage Korale division in the Kandy district, on the basis of heavy rain in the river’s upper catchment.
Level 3: Ratnapura told to evacuate
The NBRO has issued a Level 3 (evacuation) early warning for landslides covering Ratnapura, Ayagama, Pelmadulla, Kuruwita, Elapatha and Opanayake, Hiru News reported at 4.01 p.m.
A Level 2 (be alert) warning covers the Kalutara, Kandy, Kegalle, Kurunegala and Nuwara Eliya districts.
These areas are not a separate emergency from the flooding. Five of the six Level 3 areas — Ratnapura, Ayagama, Pelmadulla, Kuruwita and Elapatha — were also named on Monday morning in the Irrigation Department’s minor flood warning for the Kalu Ganga basin. The same rainfall over the same catchment is now producing two distinct hazards in the same divisions: rising water in the low ground and slope instability above it. NBRO adds Opanayake to the list; the flood warning named Nivithigala, which NBRO does not.
Not reported
Neither reservoir filing gives a water level, a percentage of capacity, or an inflow rate for any of the seven reservoirs, so how close each is to its limit cannot be judged. Victoria’s position is described only as “nearing” maximum capacity, with no figure and no stated threshold. No discharge rate is given for Polgolla, Kukule Ganga, Kala Wewa, Deduru Oya or Rajanganaya — only Ibbankatuwa’s 100 cusecs and Thabbowa’s 2,640.
The Kukule Ganga and Ibbankatuwa openings have no accompanying downstream advisory in either filing, and no divisional secretariat divisions are named for the Kuda Ganga or the Dambulu Oya.
The NBRO warning as reported carries no expiry time and no evacuation instruction beyond the warning level itself. Neither filing reports evacuations carried out, displacement, damage or casualties, and none says whether the Level 3 areas have been visited by disaster management officers.
