Site Records

St. Fillans Power Station - Lednock Dam

OS Grid Ref: NN 69045 2460
Date opened: 1957
Date closed : Operational

Lednock dam has created an artificial loch, Loch Lednock, which provides the storage for St. Fillans power station. It's reached by a public road up Glen Lednock, from Crieff. The last mile or two of the road is private and gated, but the gate is not locked and there is no objection to driving up the road to the dam.

Lednock dam is a substantial structure, 133ft high and 900ft long. It's one of only two diamond-headed buttress dams in Scotland - the other is at Errochty. Special attention was paid to the design of this dam, as it's close to the epicentre of occasional earth tremors on the faults associated with the Highland Boundary Complex, which passes close by.

One unusual feature of Lednock dam is the walkway - obviously only usuable when water is low! - which runs across the rear of the dam, behind the spillway:

Looking down Glen Lednock from the crest of the dam:

Looking back to the side of the loch, there's a tunnel outlet a couple of hundred yards upstream of the dam:

Notc much to see in high water conditions:

But in low water, it looks like this:

It's actually a double outlet; there are two tunnels. The right-hand tunnel is relatively short - only just over a mile - and intercepts the waters of the Invergeldie Burn, which would otherwise flow out of the catchment area. The left-hand tunnel is much longer - over three miles - and brings the water from the River Almond, over the hills in the next glen to the North.

When the water is low, the combined outfall flows down a waterslide into the loch:

The twin tunnels above under construction:

Finally, a look up Loch Lednock. The white building in the middle distance is the gatehouse for the tunnel to St. Fillans. Just visible in the far distance, at the head of the loch (easy to see on the high-resolution version - click the image to see this) is the small Breaclaich power station, which takes water from a high-level catchment to the South of Loch Tay, and discharges into Loch Lednock:

Words and images © 2005 Michael J. Ross