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Lower Periyar (Pambla)

Idukki district · KSEB · Periyar basin · report 18 Sep 2026, 11:00 IST

No warning — below every published alert level

Storage

71.5%

Previous 53.8%

Water level

249.90 m (819.9 ft)

FRL 253.00 m (830.1 ft)

Spillway release

Latest report

Rain forecast

12 mm

Next 72h 41 mm

Storage & water level — last 30 days

Risk breakdown

Flood risk50
Landslide risk15
Reservoir stress100
Watershed saturation14
River overflow22
  • Storage rose 17.7 points since last report
  • No official alert levels defined
  • No official alert levels are defined for this structure

Rate of rise(derived)

+2.10 m / 24 h

At the current rate, Red alert band in ~1.0 days (2.10 m to go)

Downstream exposure

Periyar below Lower Periyar power house towards Neriamangalam and Bhoothathankettu

Local bodies on this reach: Neriamangalam, Kuttampuzha, Kothamangalam, Keerampara

District control room: 1077 / 04862-233111

Rule curve — seasonal operating target

No rule curve (seasonal guide curve) is published for Lower Periyar (Pambla) in a form this platform can verify, so none is shown. Where an operating curve is published — as for Idukki after the 2018 floods — it is plotted against actual storage instead of being estimated.

Rainfall forecast — next 48 hours

Spillway releases

Current weather at the dam

Temperature
22.8°C
Humidity
96%
Rain 24h
21.6 mm
Wind
3 km/h
Gusts
11 km/h
Pressure
958 hPa

AI analysis

Lower Periyar is at no alert level, with storage rising from 61.16% to 68.02% and the water level at 249.5 m, 3.5 m below the 253 m FRL; all spillway gates remain closed with no discharge. The rise is being driven by 13.1 mm of recent rain, with another 16.4 mm forecast in 24 hours and 33 mm over 72 hours; the next alert would be triggered when the reservoir reaches its designated alert-level threshold, which is not provided.

  • Controlled release alert — Lower Periyar (Pambla) · 06 Aug 2026, 20:30 IST
  • Danger alert — Lower Periyar (Pambla) · 06 Aug 2026, 20:00 IST
  • Controlled release alert — Lower Periyar (Pambla) · 06 Aug 2026, 19:55 IST
  • Danger alert — Lower Periyar (Pambla) · 06 Aug 2026, 18:30 IST
  • Controlled release alert — Lower Periyar (Pambla) · 06 Aug 2026, 18:24 IST

Reservoir information bulletin

Commissioned
1997
Dam type
Concrete gravity
Height
Length
Gross capacity
Live capacity
Catchment area
Full reservoir level
253.00 m (830.1 ft)
Power station
Lower Periyar HEP (Pamblassery)
Installed capacity
180.0 MW
Purpose
Hydroelectric
Operator
KSEB
River
Periyar
Basin
Periyar
Nearby towns
Neriamangalam
Emergency contact
1077

The Lower Periyar scheme at Pamblassery uses releases from the upstream Periyar cascade and was commissioned in 1997 with an installed capacity of 180 MW.

Periyar river system — levels & flow

Every monitored structure on this river, ordered by how much water it is passing downstream right now.

StructureLevel / FRL (m)StorageInflowOutflowStatus
Bhoothathankettu (Barrage)Ernakulam31.00 / 34.95101.7 ft / 114.7 ft800 m³/sControlled release — water is being released in regulated quantities, not a danger warning
MullaperiyarIdukki / 46.33 / 152.0 ftNo warning — below every published alert level
Lower Periyar (Pambla)Idukki249.90 / 253.00819.9 ft / 830.1 ft71.5%No warning — below every published alert level
NeriamangalamIdukki / / No warning — below every published alert level
IdukkiIdukki721.42 / 732.432366.9 ft / 2403.0 ft61.0%No warning — below every published alert level