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Home›Flood history›Kelani Ganga

When does the Kelani Ganga flood?

Flood warnings on the Kelani Ganga come mostly between October and December, with a smaller peak in May. It’s October now, the main flood season.

Since 23 Nov 2025, its 7 gauges have recorded flooding on 25 days and alert levels on 45 days. The most recent flood was 26 Oct 2026, at Holombuwa (minor flood).

Below each line is what the river gauges recorded; above it, our estimate of how high the rivers ran, going back to 2022. Updated 27 Oct, 1:00 am (Sri Lanka time). Live Kelani Ganga levels →

Flood warnings by day, one row per year

AlertMinor floodMajor floodEstimatedRecorded
NE monsoon
Inter-monsoon
SW monsoon
Inter-monsoon
JJanFFebMMarAAprMMayJJunJJulAAugSSepOOctNNovDDec
202617d
2025~5d
2024~25d
2023~42d
2022~1d

Taller bars mean more gauges were in warning that day. Tap or hover a day for details. Earlier years are estimates.
Gauge records start 23 Nov 2025

When do flood warnings happen?

Share of days in each month with at least one gauge at alert or worse on the Kelani Ganga.

JanFebMarAprMayJunJulAugSepOctNovDec
Estimated, 2022 to now Measured at gauges, Nov 2025 to now

Biggest flood events on the Kelani Ganga

Runs of days with minor or major flooding, ranked by the worst day.

Year by year

Kelani Ganga: about 48 affected days a year in gauge records since 23 Nov 2025.

Before 23 Nov 2025 there are no gauge records here; estimates suggest about 46 affected days a year in 2022–2024.

YearAffected daysMajor floodMinor floodAlertWorst day
2026(so far)Recorded
35
6
11
18
Major flood 6Minor flood 11Alert 18
Worst day: 3 Aug · major flood at 1 gauge
2025Recorded from 23 Nov
27
7
6
14
Major flood 7Minor flood 6Alert 14
Worst day: 28 Nov · major flood at 5 gauges
2024Estimated
46
8
17
21
Major flood 8Minor flood 17Alert 21
Worst day: 27 May · major flood at 4 gauges (estimated)
2023Estimated
83
18
24
41
Major flood 18Minor flood 24Alert 41
Worst day: 5 Nov · major flood at 4 gauges (estimated)
2022Estimated
9
1
–
8
Major flood 1Minor flood 0Alert 8
Worst day: 14 May · major flood at 1 gauge (estimated)

Affected means at least alert level. A day counts once, at the worst level any gauge reached. Years before the gauge records start are estimates.

Flood history by gauge on the Kelani Ganga

  • Deraniyagala
  • Glencourse
  • Hanwella
  • Holombuwa
  • Kithulgala
  • Nagalagam Street
  • Norwood

About this data

Measured: the highest level each gauge reached that day, compared with the Department of Irrigation’s alert, minor-flood and major-flood levels.

Estimated: for years before the gauge records here begin, we estimate how high each river ran from a global river-flow model. These are not official warnings. They show the flood seasons and the big floods well, but can miss the exact day or gauge, especially on small rivers.

Sources: Department of Irrigation river gauges; earlier gauge readings saved by lk_irrigation; river-flow estimates by Open-Meteo. Download the daily records.

Sri Lanka Water Levels

Live river and reservoir levels across Sri Lanka, with flood forecasts.

Rivers

  • Aththanagalu Oya
  • Deduru Oya
  • Gal Oya
  • Gin Ganga
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  • Kalu Ganga
  • Kelani Ganga
  • Kirindi Oya
  • Kumbukkan Oya
  • Ma Oya
  • Maduru Oya
  • Maha Oya
  • Mahaweli Ganga
  • Malwathu Oya
  • Mee Oya
  • Menik Ganga
  • Nilwala Ganga
  • Walawe Ganga
  • Yan Oya

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Data and credits

Readings from the Department of Irrigation and the Mahaweli Authority. Warnings from the Disaster Management Centre. Rain forecasts from Open-Meteo. Map © OpenStreetMap contributors; some river lines from the Department of Irrigation.

Not an official warning service. In an emergency, call 117.

© 2026 Sri Lanka Water Levels. Built in Sri Lanka. · Made by @shakeeb_x · Automated updates: @waterlevelslk

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