On a tourist map the western Nilgiris look like a loose collection of blue shapes: Avalanche, Emerald, Upper Bhavani, Parsons Valley, Porthimund. On an electricity map they are one machine. Rain is stored high, moved sideways through the mountain, released down a pressure shaft, used by a turbine and then caught again for another drop. The landscape has storeys.
Six stations, not one dam
Tamil Nadu’s Statistical Handbook for 2022–23 lists six Kundah power houses. Kundah I has 60 MW of installed capacity, II has 175, III has 180, IV has 100, V has 40 and VI has 30. Together they make 585 MW. The dates run from 1960–64 for the first two, through 1965–78 and 1966–78 for the next pair, 1964–88 for the fifth, and 2000 for the sixth.
That spread matters. “The Kundah scheme” was not a wall completed on one date. It was decades of dams, tunnels, valve houses, penstocks, substations and transmission lines, fitted to the levels of a whole range. Some parts were generating while others were still being planned or enlarged. What looks from a road like an isolated lake may feed machinery many kilometres away and hundreds of metres lower.
Why the roads stop
Engineering created roads into places that previously had only pastoral and forest routes. Those roads remain on maps, which is the source of a modern mistake: a navigation service can draw a line along an inspection road and make it look like an invitation. It is not. A road built to inspect a dam, control an intake or fight a forest fire can be physically driveable and legally closed at the same time.
There are two sets of reasons for the barriers. TANGEDCO and water authorities control live industrial and drinking-water infrastructure. The Forest Department controls reserved forest and national-park land around it. At several points both interests overlap. A barrier is therefore not an inconvenient tourist gate waiting for a fee; it can be the boundary between a public road and a workplace, a catchment, wildlife habitat or all three.
Water before scenery
Parsons Valley is a drinking-water catchment for Ooty. Upper Bhavani belongs to the headwater country of the Bhavani river. Porthimund is part of the hydro-electric chain. Their quietness is not proof that nobody minds where a visitor walks. Reservoir margins can conceal steep ground, intake currents and sudden changes of level, while fuel, litter or human waste in a catchment becomes somebody else’s water.
The responsible way to see the scheme is from the public road, with the pattern in mind. Look for a high reservoir, the line of a tunnel or pipe across a contour, the sudden appearance of a power house in a lower valley and transmission lines climbing away. Do not aim a camera through a gate or walk onto a dam crest unless staff have explicitly opened it.
A new kind of battery
Hydro-electricity can respond quickly when demand rises, which makes stored water valuable beyond the total number of units generated. Tamil Nadu has also planned pumped-storage development at Kundah: power used when supply is abundant would lift water back uphill, ready to generate again at a peak. The proposal describes 500 MW in four 125 MW units. Whether or when every phase operates is a project-status question, but the idea fits the mountain perfectly — not merely water running down, but energy stored by moving it back up.
That is why Kundah is worth understanding even when a gate stays shut. Ooty’s lights, Tamil Nadu’s evening demand, monsoon rain on a grass slope and a guarded reservoir road are parts of the same story. The blue shapes are not attractions that happen to generate electricity. They are an electricity and water system that happens to be beautiful.