Will Sedawatta flood in the next hour?

Sedawatta flood risk right now: Alert. This is an estimate based on the Nagalagam Street gauge on the Kelani Ganga (2.2 km away), which read 3.8 ft as of Tue, 27 Oct, 1:04 am (Sri Lanka time). In the next hour the Kelani Ganga at Nagalagam Street could rise to about 4.0 ft (3.9–4.3 ft). It will likely reach the alert level. This is a forecast for the river, not an official warning, and streets can flood before the river reaches a flood mark.

How is the flood risk for Sedawatta worked out?

From the nearest river gauge ({gauge}, 2.2 km away), recent and expected rain, the gauge's forecast and any official warning. It is an estimate for the town, not an official warning, and streets can flood before the river reaches a flood mark.

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.

Is Sedawatta flooding?

Sedawatta, Colombo

Sedawatta flood risk right now: Alert. This is an estimate based on the Nagalagam Street gauge on the Kelani Ganga (2.2 km away), which read 3.8 ft as of Tue, 27 Oct, 1:04 am (Sri Lanka time).

Reading at 1:04 am · 45 min ago

Alert

3.8 ft

Next hour

Rising with the tide, about the same once the tide is allowed for

Next 24 hours

River could reach alert level in about 1 h

Move valuables up, charge your phone

Experimental estimate. There is no river gauge in Sedawatta; this uses Nagalagam Street, 2.2 km away, plus rain at the town and official warnings.

Call 117 Colombo DMC office

Details

How this estimate works

· Starts from the river gauge's own level and forecast, the same as the gauge page.
· Heavy rain here (50 mm in 6 hours or 100 mm in 24 hours) raises it by one step, never more.
· Your own street level, if you set one, and official warnings can raise it further.
· It never says flooding is happening: only a measurement can show that.

Why

Irrigation Department has issued a flood warning for Kelani Ganga
Kelani Ganga at Nagalagam Street is 3.8 ft, rising (near alert level)
Nagalagam Street may reach alert level in about 1 hours
55 mm of rain in the last 24 hours
Water in Sedawatta drains through canals into the river. When the river is high, rain can stay on the lowest ground near them.

Your river

Nagalagam Street

Kelani Ganga · 2.2 km away

Normal3.8 ft1:04 am

Is this right?

Each answer helps us improve the forecast for your area.

Based on: Nagalagam Street gauge on the Kelani Ganga, 2.2 km away

Set your street's flood level

At what Nagalagam Street reading does water reach your street? Saved on this device only, never sent anywhere.

Rain in Sedawatta

Moderate rain in the last 24 hours (55 mm). Moderate rain expected early this morning, about 20 mm in the next 24 hours.

mm per hour

Tap or hover a bar to see that hour.

Rain map

It is around high tide now. Canals drain slowest for the next hour or so. Next high tide around 3:03 pm.

Sea level at the Kelani mouth is rising (reading 12:30 am). Canal levels: CUrW / SLLDC (pub.curwsl.org)

How water drains here

Water here drains into the Kolonnawa canal and out to the Kelani through the North Lock pumps and gates at Nagalagam Street and the Gothatuwa gates. When the sea is high or the Kelani is high the canal cannot empty, so heavy rain plus high tide or a high river slows draining.

The canals here are higher than usual right now, so they drain more slowly. This is context, not a flood warning.

Colombo canals explained

Canal levels now · Kolonnawa canal basin

Sea at the Kelani mouth
1.8 ft above sea level
Reading 12:30 am
Wellampitiya NNot reporting

Did the streets near you get water today?

Your answer helps us check our warnings. It is anonymous: we save only the town and your answer. Nobody sees single answers; we show only totals of 3 or more.

When? (optional)

River map

GaugeReservoirTap a gauge or reservoir for details.

Reservoirs upstream

Official flood map

In the Irrigation Department's maps of past floods (Kelani Ganga 2016 major flood, 1989 critical flood), these Grama Niladhari divisions around Sedawatta were partly or fully under water:

Welewatta2016, 1989
Wellampitiya2016, 1989
Kotuvila2016, 1989
Kuruniyawatta2016, 1989
Kittampahuwa2016, 1989
Dahampura 12016
Veheragoda2016, 1989
Orugodawatta2016, 1989
and 17 more nearby

Flood help and phone numbers

Common questions

Is Sedawatta flooding now?: Sedawatta flood risk right now: Alert. This is an estimate based on the Nagalagam Street gauge on the Kelani Ganga (2.2 km away), which read 3.8 ft as of Tue, 27 Oct, 1:04 am (Sri Lanka time).
Will Sedawatta flood in the next hour?: Sedawatta flood risk right now: Alert. This is an estimate based on the Nagalagam Street gauge on the Kelani Ganga (2.2 km away), which read 3.8 ft as of Tue, 27 Oct, 1:04 am (Sri Lanka time). In the next hour the Kelani Ganga at Nagalagam Street could rise to about 4.0 ft (3.9–4.3 ft). It will likely reach the alert level. This is a forecast for the river, not an official warning, and streets can flood before the river reaches a flood mark.
How is the flood risk for Sedawatta worked out?: From the nearest river gauge ({gauge}, 2.2 km away), recent and expected rain, the gauge's forecast and any official warning. It is an estimate for the town, not an official warning, and streets can flood before the river reaches a flood mark.
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.

Kelani Ganga · Sources: Department of Irrigation gauges, Open-Meteo rain, Disaster Management Centre warnings.