Will the Deduru Oya at Moragaswewa rise in the next hour?

In the next hour the Deduru Oya at Moragaswewa could rise to about 15.6 ft (15.5–15.7 ft). It will likely reach the alert level. This is a forecast from the recent trend, the gauges upstream and rain, not an official warning.

What is the flood level at Moragaswewa?

The official marks for this gauge are alert 15.6 ft, minor flood 19.7 ft, major flood 23.0 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.

Moragaswewa Deduru Oya water level

As of Tue, 27 Oct, 12:06 am (Sri Lanka time), the Deduru Oya at Moragaswewa was 15.5 ft, close to the 15.6 ft alert level, and rising.

In the next hour it could rise to about 15.6 ft (15.5–15.7 ft). It will likely reach the alert level.

Deduru Oya reservoir releasingVery large · ~290,000 L/s8 gates open

10,400 cusecs

1 cusec = 1 cubic foot of water a second, about 28 litres.

Deduru OyaMoragaswewaChilaw~4–5 h

Low areas along the river may see water rise.

Irrigation Department · 26 Oct How releases work

Reading at 12:06 am · 50 min ago

Alert

15.5 ft

Deduru Oya reservoir is releasing 10,400 cusecs through 8 gates

Next hour

Rising slowly

Next 24 hours

Could reach alert level in ~1 hour

Move valuables up, charge your phone

The river is likely to reach alert level around 1 am tonight (in about 1 hour).

Call 117 Kurunegala DMC office

Details

Likely to reach alert level around 1 am tonight (in about 1 hour) (about 90% chance).

Published as 4.72 m (alert 4.8 m, minor flood 6.0 m, major flood 7.0 m)

Elevated river-flow outlook this week.

In	Level	80% range	At
1h	15.6 ft	15.5 to 15.7	1:06 am
3h	15.8 ft	15.4 to 16.2	3:06 am
6h	16.0 ft	15.2 to 20.2	6:06 am
12h	15.9 ft	14.7 to 23.0	12:06 pm
24h	15.4 ft	14.0 to 28.8	12:06 am

Alert (15.6 ft): likely, about 9 in 10, from about 1:06 am
Minor flood (19.7 ft): possible, about 6 in 10, from about 6:06 am

Is this right?

Each answer helps us improve the forecast for your area.

Unusual rise

Unusual rise here — one or more natural drivers don't fit.

Why?

· Rising at +0.3 ft/h despite only 2.6mm/6h of rain across the basin.

Water level

How this river reacts to rain

A slow river. Rain close to Moragaswewa shows up in the river in about 18 hours.
About 35 mm of rain over 24 hours, averaged over the catchment, has usually come before a rise of 1 ft or more.

Learned from 11 months of readings and satellite rain. A guide, not a forecast.

This gauge’s forecasts: the next hour is typically off by about 0.2 ft; 24 hours ahead, by about 8.1 ft (last 30 days, 24 checks).

River map

GaugeReservoirWater being releasedTap a gauge or reservoir for details.

When does Moragaswewa flood?

Flood warnings come mostly in November.

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

Recent floods

11 Dec 2025Major flood
27 Nov – 28 Nov 2025Major flood
24 Nov 2025Minor flood

Every day since 2022, year by year

Other stations

Reservoirs upstream

Deduru OyaSpillingVery large

In the newsNews reports, not official.

RiverSource: Newswire22 Oct, 10:21 am (5 d ago)
Flood risk in 09 areas as Deduru Oya Reservoir opens spill gates(opens the news site in a new tab)
Eight spill gates of the Deduru Oya Reservoir have been opened, releasing water into the Deduru Oya at a rate…

Towns that depend on this gauge

Flood help & emergency numbers

Common questions

Is Moragaswewa flooding now?: As of Tue, 27 Oct, 12:06 am (Sri Lanka time), the Deduru Oya at Moragaswewa was 15.5 ft, close to the 15.6 ft alert level, and rising.
Will the Deduru Oya at Moragaswewa rise in the next hour?: In the next hour the Deduru Oya at Moragaswewa could rise to about 15.6 ft (15.5–15.7 ft). It will likely reach the alert level. This is a forecast from the recent trend, the gauges upstream and rain, not an official warning.
What is the flood level at Moragaswewa?: The official marks for this gauge are alert 15.6 ft, minor flood 19.7 ft, major flood 23.0 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.