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Ceannacroc Tunnel [Access Portal]

Ceannacroc, Glen Moriston, Inverness-shire.

Tunnel, Hydro electric scheme.

Main access tunnel portal to subsurface (Ceannacroc) power station.

"Ceannacroc is a medium-head (295ft) development of the 'traditional' kind (dam, low-pressure tunnel, surge shaft, high-pressure shaft/tunnel, power station, short tailrace). It is noteworthy for being the first major underground power station built in the UK... A tunnel supplies Ceannacroc from Loch Clunie, the tailrace from Ceannacroc discharges into the River Moriston, which is dammed again a few miles downstream, and the water utilised in the lower stage development at Glenmoriston.

The bed of Loch Clunie is gently-sloping, so rather than the 'conventional' intake tower, water is led to the tunnel entrance through a submerged 'cutting' on the bed of the loch. The gates and screens are housed in two separate shafts a little distance away, one either side of the main A82 trunk road. From there the water is taken to the main Ceannacroc tunnel, 14,000ft long, of 12' equivalent diameter in a horseshoe section, to the surge chamber. From there the water falls down a vertical high-pressure shaft, from the base of the shaft a short length of high-pressure tunnel leads to Ceannacroc power station, which is constructed underground. After passing through the turbines at Ceannacroc, a 1,700ft tailrace tunnel discharges the water into the River Moriston. A side-stream intake along the route of the low-pressure tunnel captures the flow of the Allt nam Peathrain, and an extensive system of aqueducts and intakes captures the flow of the River Doe & tributaries." [Corestore]

Alternate Names: None recorded.

Notes: "Storage is provided at Lochs Loyne and Clunie, which have both been enlarged by dams, the water from Loch Loyne being led, via a small power station, through a tunnel to Loch Clunie." [Corestore]

Given length & VR are approx. (excludes River Doe branch & tailrace tunnel).

Hydrographic Feeds: Loch Cluanie / River Doe / Allt nam Peathrain

Hydrographic Resurgences: River Moriston