Mullaperiyar

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.

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.