History · Engineering · 5 min read

Sengulam: The Small Dam That Gives the Same Water a Second Life

In the green valleys between Munnar and Adimali, a little masonry dam stores water that has already turned the turbines at Pallivasal, pumped uphill and sent through the mountain to turn them again. The quiet engineering of Sengulam.

By GK Global, Adimali, Munnar · Trails & Tales by GK

Most dams catch rain. Sengulam catches something else: water that has already done a day's work. High above, at Pallivasal, the Muthirapuzha's water has fallen through pipes and spun the turbines of Kerala's first power station. Instead of letting it flow away down the river, the engineers of the 1950s caught it, pumped it a little way uphill, and sent it through the hills to a small reservoir at Sengulam, from where it falls again to drive a second power station. It is one of the cleverest, and least known, pieces of engineering in the High Range.

Using the water twice

By the early 1950s, the Pallivasal power station was running, but its spent water simply returned to the Muthirapuzha. The engineers of the Travancore-Cochin state saw that there was still a great fall of land below Pallivasal, and planned the Sengulam Hydroelectric Project to use it. The scheme works in stages, according to the KSEB's dam-safety records:

• The tailwater from the Pallivasal power station is collected in a forebay nearby.
• From there it is pumped up a little over 9 m and carried through a tunnel about 1.7 km long to the Sengulam reservoir.
• From the reservoir, a power tunnel about 1.76 km long, a low-pressure pipe of about 800 m and a twin penstock about 960 m long carry the water down to the power station.
• At Vellathooval, four Pelton turbines generate electricity, and the water returns to the Muthirapuzha, flowing on to the Kallarkutty reservoir and the next stations downstream.

The project was commissioned in the mid-1950s, and the dam was completed in 1957. The station produces about 180 million units of electricity in an average year. It is one link in a remarkable chain: the same water, stored at Kundala and Mattupetty, falls through Pallivasal, then Sengulam, then continues through the Neriamangalam and Lower Periyar stations on its way down the Periyar. (Read the Pallivasal story and The Titans of the Ghats.)

The dam and its valley

Sengulam is a small, quiet dam: a curve of grey masonry across a stream, with water spilling over its crest after the rains, set among cardamom and pepper gardens, coconut palms and small farms. It sees far fewer tourists than Mattupetty or Kundala, and that is its charm, though the KSEB now runs short speedboat rides on the reservoir. The reservoir is calm and green, and kingfishers, egrets and cormorants fish its edges. In the monsoon, the hills around stream with waterfalls.

The valley around Vellathooval is also home to the Panniyar power station, fed from Ponmudi, making this small town a meeting point of two hydroelectric schemes.

Visitor's guide

• Getting there: near Kunchithanny, on the roads between Munnar, Pallivasal, Vellathooval and Adimali; about an hour from Munnar.
• Access: the dam is a KSEB installation. You can enjoy the view from the road and public areas, but follow the instructions of staff, keep out of restricted areas and check before photographing structures. The KSEB's hydel tourism wing runs a small boating centre here (it lists the site as Chenkulam), with short speedboat rides and an entry pass, generally from about 9 am to 5 pm.
• Safety: never swim in the reservoir or the river below the power station; water can be released without warning.
• Nearby: Kallarkutty dam, the waterfalls along the Munnar–Adimali road, and Ponmudi. (Read the waterfalls of Idukki.)