Site Records

Clachan Power Station - Surge Pond

The surge shaft at Clachan is an inclined shaft, 20' in diameter and sloping at 39º to the horizontal, in line with the pressure shaft to the power station which lies below it, as the following illustration should make clear:

A more detailed illustration of the area of the surge shaft, pond, expansion gallery, and construction adit (this is really best viewed at high-resolution; click on the image and a high resolution version will be displayed):

A General view of the surge pond, high on the hillside above Loch Fyne. A slight hollow closed by a small dam, at the right side of the pond is the end of the aqueduct bringing water from the Kilblaan catchment. The top of the surge shaft itself is below the large concrete sructure covered with metal joists and grille.

Another view of the surge pond, taken from on top of the Kilblaan aqueduct, which is flowing beneath the concrete slabs.

This view is taken standing on the concrete structure atop the surge shaft, looking through the grille. The shaft was in fact surging on the occasion of this visit, the water level rising and falling with a period of approximately 5 minutes. Here it is at the top of the surge...

As the level drops, the top of the shaft becomes visible...

...now the water is at its lowest level, perhaps 60' down the shaft. The cascade of water flowing down the shaft represents the inflow from the Kilblaan catchment.

Words and images © 2003 Michael J. Ross