Lower Periyar (Pambla)
Idukki district · KSEB · Periyar basin · report 01 Nov 2026, 11:00 IST
Storage
77.7%
Previous 74.1%
Water level
250.60 m (822.2 ft)
FRL 253.00 m (830.1 ft)
Spillway release
—
Latest report
Rain forecast
26 mm
Next 72h 52 mm
Storage & water level — last 30 days
Risk breakdown
- • Only 2.40 m of freeboard left below FRL
- • No official alert levels defined
- • No official alert levels are defined for this structure
Rate of rise(derived)
+0.40 m / 24 h
At the current rate, Red alert band in ~3 days (1.40 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
- 21.9°C
- Humidity
- 99%
- Rain 24h
- 19.8 mm
- Wind
- 3 km/h
- Gusts
- 7 km/h
- Pressure
- 956 hPa
AI analysis
Lower Periyar is at no alert level, with storage at 76.81%, up from 68.02%, and the water level at 250.5 m—2.5 m below the 253 m FRL; all spillway gates are closed and spill is 0 cumecs. Recent rain was only 0.2 mm, but forecasts of 8 mm in 24 hours and 50.9 mm in 72 hours, along with a flood risk of 43, could raise inflows; the next alert would be triggered when the reservoir reaches its prescribed alert-level water 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
Environmental & carbon accounting
Insufficient data- Reservoir methane (gross)
- Not enough data /yr
- Green carbon — catchment forest
- Not enough data /yr
- Blue carbon — sediment burial
- Not enough data /yr
- Hydropower grid offset
- 3,95,146 t CO₂e /yr
CH₄ from flooded land × GWP-100 (27), age-adjusted
Western Ghats forest sink, 60% forest cover assumed
—
vs CEA grid 0.716 kg CO₂/kWh, 35% capacity factor
Net catchment balance: Not enough data/yr (forest + sediment sinks minus reservoir methane)
Estimate, not a measurement — built from IPCC 2019 Flooded Lands factors and public dam data. Kerala does not publish measured reservoir emissions. Credits shown are indicative, not registered. How this is calculated
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.
| Structure | Level / FRL (m) | Storage | Inflow | Outflow | Status |
|---|---|---|---|---|---|
| Bhoothathankettu (Barrage)Ernakulam | 32.00 / 34.95105.0 ft / 114.7 ft | — | — | 32 m³/s | Controlled release — water is being released in regulated quantities, not a danger warning |
| MullaperiyarIdukki | — / 46.33— / 152.0 ft | — | — | — | No warning — below every published alert level |
| Lower Periyar (Pambla)Idukki | 250.60 / 253.00822.2 ft / 830.1 ft | 77.7% | — | — | No warning — below every published alert level |
| NeriamangalamIdukki | — / —— / — | — | — | — | No warning — below every published alert level |
| IdukkiIdukki | 721.96 / 732.432368.6 ft / 2403.0 ft | 62.7% | — | — | No warning — below every published alert level |