The district takes its name from the gorge — idukku means a narrow pass in Malayalam — where the Periyar river squeezes between two granite hills, Kuravan and Kurathi. In the 1970s engineers closed that gap with a double-curvature concrete arch about 169 m high, built with Canadian assistance and commissioned in 1976. It remains one of the highest arch dams in Asia.
The Idukki Arch Dam works together with two others: Cheruthoni, a massive straight gravity dam a kilometre away, and Kulamavu, further west. Between them they hold a single reservoir of around 60 km², whose water drops through tunnels to the underground power station at Moolamattom — for decades the backbone of Kerala’s electricity supply.
Top things to do at Idukki Arch Dam
See the arch from below and above
The best overall view is from Hill View Park near Cheruthoni, a landscaped hilltop with both dams and the reservoir laid out below. From the road at Cheruthoni you look straight up at the curve of the arch.
Walk the dams when they are open
Public access to the top of the Idukki and Cheruthoni dams is restricted for security. They have traditionally been opened to visitors during the Onam and Christmas–New Year holiday seasons and, in recent years, on some other days, with battery buggies running between the two. Rules, dates and ticketing change — check the current notice from the Kerala State Electricity Board or the district tourism office. Cameras and phones may be restricted on the dam.
Drive to Kalvari Mount
About 10 km towards Kattappana, a short steep road climbs to Kalvari (Calvary) Mount, a ridge-top viewpoint over the forested fingers of the reservoir. It is the finest panorama in central Idukki, especially early and late in the day.
Take a boat or look for wildlife
The reservoir is bordered by the Idukki Wildlife Sanctuary. Forest-department boat trips on the reservoir operate at times from near Cheruthoni; ask locally whether they are running.
How to get to Idukki Arch Dam
- From Kochi: about 110–120 km, 3–3.5 hours via Muvattupuzha and Thodupuzha, climbing past Kulamavu Dam to Cheruthoni and Painavu, the district headquarters.
- From Munnar: about 60–65 km south via Adimali, around 2 hours.
- From Thekkady: about 55–65 km via Kattappana, around 2 hours — Kalvari Mount is on the way.
Insider tips
- Plan around the viewpoints, which are always open, and treat a walk on the dam as a bonus.
- The reservoir is fullest and greenest from about August to January. In a dry spring the water can be very low.
- When the Cheruthoni shutters are opened after extreme rain (as in 2018), roads downstream may be closed — follow official advice.
- There are only simple hotels around Cheruthoni; most visitors come as a stop between Munnar, Thekkady and Vagamon.
Tours that include Idukki Arch Dam
These guided trips cover Idukki Arch Dam or combine easily with a visit:
Private day trip from US$123 Vagamon Day Tour from Cochin — Kerala Hill Station Trip
Vagamon is the gentlest of Idukki’s hill stations and the closest to Kochi. This private day trip covers the pine forest, the meadows, tea gardens and viewpoints, and gets you back to the coast the same evening.
- Vagamon’s pine forest and rolling meadows
- Tea plantations and hill viewpoints
- Private car and guided sightseeing from Kochi
Multi-day tour Cochin: 5-Day Kerala Tour with Munnar, Thekkady and Alleppey
The classic Kerala loop in one booking: Kochi up to Munnar, across the high ranges to Thekkady, then down to the backwaters at Alleppey for a houseboat cruise. Several versions are sold on the same listing, so check what transport and accommodation your option includes.
- Munnar’s tea gardens and hill views
- Thekkady’s spice plantations
- Houseboat cruise on the Alleppey backwaters
