Is Nakkala flooding now?

As of Tue, 27 Oct, 2:00 am (Sri Lanka time), the Kumbukkan Oya at Nakkala was 3.2 ft, below the 16.4 ft alert level, and falling.

Will the Kumbukkan Oya at Nakkala rise in the next hour?

In the next hour the Kumbukkan Oya at Nakkala should stay about the same (3.1–3.3 ft). This is a forecast from the recent trend, the gauges upstream and rain, not an official warning.

What is the flood level at Nakkala?

The official marks for this gauge are alert 16.4 ft, minor flood 19.7 ft, major flood 24.6 ft. Alert means the river has reached the alert mark: move valuables up and charge your phone. Minor flood means water is spilling over low ground, and major flood means move to safety.

Where does this come from and how often does it update?

River readings come from the Department of Irrigation's gauges, roughly once an hour, and this page checks for new ones every minute. This site is independent and not an official warning service: follow the Disaster Management Centre and call 117 in an emergency.

Nakkala Kumbukkan Oya water level today (live)

Reading at 2:00 am · 49 min ago

Normal

3.2 ft

Next hour

Steady

Next 24 hours

No estimate yet

The level should remain steady at about 3.2 ft in an hour.

Details

Steady: about 3.2 ft in an hour.

Published as 0.98 m (alert 5.0 m, minor flood 6.0 m, major flood 7.5 m)

In	Level	80% range	At
1h	3.2 ft	3.1 to 3.3	3:00 am

Local trend

-0.03 ft/h

Upstream avg

n/a (top)

Rain that fell: 0.6 mm in the last 3 hours, 18 mm in the last 24 hours at this gauge (moderate rain)
Rain forecast: 22 mm in the next 24 hours over the catchment (moderate rain). Forecast model estimate.

Satellite estimate of rain over the catchment: 3.4 mm in the last 6 hours, 10.1 mm in the last 24 hours (to 2:30 am). In this dry-zone area it often reads much higher than the gauges, so treat it as an upper figure. GSMaP data by Japan Aerospace Exploration Agency (JAXA)

· Trend only: a rain model was fitted and tested on 8 days but was no more accurate than "level stays put" at any horizon (best: 12 h, 0.20 vs 0.18 error).
· Forecast model estimate of catchment rain (Open-Meteo, area average over 6 grid cells above this gauge): 2.3 mm modelled for the last 6 hours, 14 mm modelled for the last 24 hours, 22 mm forecast for the next 24 hours. The model's past hours often read lower than the gauges, so they are not what fell; this note is for context.
· Topmost gauge on its river: no gauge upstream, so only its own trend (plus catchment rain) is available.

How this is worked out
· This gauge's own recent changes and the other gauges on the river, fitted to about 11 months of hourly readings (one hour ahead only). In a backtest on the last 60 days it missed by less than 'no change'. This is the topmost gauge on its river, so there is no upstream gauge; the catchment rain above is the only upstream signal.

Is this right?

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Water level

This gauge’s forecasts: the next hour is typically off by about 0.04 ft (last 30 days, 27 checks).

When does Nakkala flood?

Flood warnings come mostly in November.

It’s October: usually a quieter month here, though heavy rain can still bring floods.

Recent floods

Other stations

Towns that depend on this gauge

Monaragala

Flood help & emergency numbers

Common questions

Is Nakkala flooding now?: As of Tue, 27 Oct, 2:00 am (Sri Lanka time), the Kumbukkan Oya at Nakkala was 3.2 ft, below the 16.4 ft alert level, and falling.
Will the Kumbukkan Oya at Nakkala rise in the next hour?: In the next hour the Kumbukkan Oya at Nakkala should stay about the same (3.1–3.3 ft). This is a forecast from the recent trend, the gauges upstream and rain, not an official warning.
What is the flood level at Nakkala?: The official marks for this gauge are alert 16.4 ft, minor flood 19.7 ft, major flood 24.6 ft. Alert means the river has reached the alert mark: move valuables up and charge your phone. Minor flood means water is spilling over low ground, and major flood means move to safety.
Where does this come from and how often does it update?: River readings come from the Department of Irrigation's gauges, roughly once an hour, and this page checks for new ones every minute. This site is independent and not an official warning service: follow the Disaster Management Centre and call 117 in an emergency.