Where does the reservoir information come from?

From the Irrigation Department's daily reservoir sheet and the Mahaweli Authority's daily report. Both update about once a day, so check the date shown. This site is independent: for spill-gate warnings follow the Disaster Management Centre and call 117.

Sri Lanka Water LevelsLive river-gauge readings

Thissa Wewa

Anuradhapura

Thissa Wewa reservoir is not releasing water and is 97% full. Irrigation Department, 26 Oct.

Holding

As of 26 Oct · Checked 10 min ago

Thissa Wewa: Thissa Wewa — Photo: David Stanley from Nanaimo, Canada, CC BY 2.0 via Wikimedia Commons

97%full

19.0 of 19.5 ft

0.5 ft below full

Level +0.25 m since 23 Oct.

Mahaweli Authority: 109% (26 Oct)

Irrigation Department · 26 Oct

Release now

Only canal outlets are open

Outlet gates 24 cusecs

Irrigation Department · 26 Oct

Rain, day before: 0 mm; Irrigation Department · 26 Oct
Holds when full: ~4.3 million m³; Irrigation Department · 26 Oct
Source: Irrigation Department · 26 Oct Mahaweli Authority · 26 Oct

Recent days

Water depth, % of full supply
Released downstream · Release (cusecs)
Outlet gates

History starts 23 Oct 2026.

Where the water goes

No river gauge of ours is directly below this reservoir.

Figures from the daily Irrigation Department and Mahaweli Authority reports. A blank there shows here as “no data”, never zero.

Common questions

Is Thissa Wewa releasing water?: Thissa Wewa reservoir is not releasing water and is 97% full. Irrigation Department, 26 Oct.
Where does the reservoir information come from?: From the Irrigation Department's daily reservoir sheet and the Mahaweli Authority's daily report. Both update about once a day, so check the date shown. This site is independent: for spill-gate warnings follow the Disaster Management Centre and call 117.