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Mullaperiyar

Idukki district · Tamil Nadu WRD · Periyar basin

No warning — below every published alert level

Storage

Water level

FRL 46.33 m (152.0 ft)

Spillway release

Latest report

Rain forecast

10 mm

Next 72h 43 mm

Storage & water level — last 30 days

Risk breakdown

Flood risk3
Landslide risk12
Reservoir stress0
Watershed saturation10
River overflow1
  • No official alert levels defined
  • No official alert levels are defined for this structure

Rate of rise(derived)

Trend needs two bulletins

Projection needs 3 days of bulletins (0 held).

Downstream exposure

The downstream reach and local body list for Mullaperiyar have not been transcribed from a District Disaster Management Plan yet, so none are shown.

District control room: 1077 / 04862-233111

Rule curve — seasonal operating target

No rule curve (seasonal guide curve) is published for Mullaperiyar 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
20.0°C
Humidity
97%
Rain 24h
10.0 mm
Wind
3 km/h
Gusts
12 km/h
Pressure
900 hPa

AI analysis

An AI analysis for this reservoir will appear after the next scheduled briefing.

  • Watch alert — Mullaperiyar · 06 Aug 2026, 18:30 IST
  • Watch alert — Mullaperiyar · 04 Aug 2026, 05:45 IST

Reservoir information bulletin

Commissioned
1895
Dam type
Composite gravity (lime-surkhi masonry)
Height
53.7 m (176.0 ft)
Length
366 m (1200.3 ft)
Gross capacity
443.2 MCM
Live capacity
299.1 MCM
Catchment area
624 km²
Full reservoir level
46.33 m (152.0 ft)
Power station
Lower Periyar Power House (Tamil Nadu, 175 MW)
Installed capacity
Purpose
Irrigation and power diversion to Tamil Nadu; Periyar Tiger Reserve reservoir
Operator
Tamil Nadu Water Resources Department (operated under 1886 lease; Kerala holds the land)
River
Periyar
Basin
Periyar
Nearby towns
Kumily, Vandiperiyar, Vallakkadavu, Upputhara, Thekkady
Emergency contact
Idukki District Control Room 1077 / KSDMA 1070

Built 1887-1895 by Col. John Pennycuick across the Periyar at its confluence with the Mullayar, the dam diverts water through a tunnel to the Vaigai basin in Tamil Nadu. Its 152 ft (46.33 m) design FRL was cut to 136 ft in 1979 on safety grounds, restored to 142 ft (43.28 m) by the Supreme Court in 2006 and reaffirmed in 2014, with a Supervisory Committee monitoring the rule level. Because the dam is operated by Tamil Nadu, its readings are published through the Supervisory Committee and Idukki district administration rather than the KSEB or Kerala Irrigation bulletins, so no automated KSDMA measurement feed exists for it.

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