Dundreggan Dam

Dundreggan dam provides a degree of storage for Glenmoriston Power Station (see separate item) which lies 100m directly beneath the downstream face of the dam. It is a gravity dam some 55 feet high and 100 feet long. The dam has two large radial gates flanking a central drum gate which are necessary because of the occasional heavy floods experienced in this area. The dam is small in relation to the size of the catchment and so the water levels often change very rapidly. The dam also houses a small compensation set and a vertical access shaft running down to the turbine hall floor of Glenmoriston Power Station. Borland type fish lift is also in operation. Dundreggan dam is a good example of a dam designed to meet the requirements of flood management with the large gates allowing accurate control of the spill of the dam. It is also unusual in having an integrated power station located some 100 meters below the foot of the dam. The dam has a degree of later alteration, following refurbishment in 1999 including the construction of additional office space and automated trash screen cleaners. PL Payne,1988, 5; E Wood, 2002, 38; J Miller, 2002.

The Great Glen scheme: Garry/Moriston

The garry part of the scheme uses the storage facility at Loch Quoich to supply Quoich power station via a tunnel from the dam, which is a rockfill type. Two further dams were required at the west end ofthe loch. The outflow goes vis the River Garry to Loch Garry, and eventually via a tunnel to Invergarry power station at Loch Oich. There is a dam at the east end of Loch Garry. A fish stopper and trap were built down stream of Quoich power station.

Storage for Moriston section was provided by damming Loch Loyne and Loch Cluanie, and interconnecting them by a tunnel. A second tunnel from Loch Cluanie supplies Ceannacroc power station which discharges int the River Moriston, which in turn feeds Loch Dundreggan. This loch is also fed by the outflow of Livishie power station, supplied by a system of aqueducts. Glenmoriston power station is just below the Dundreggan dam. Its outflow reaches the River Moriston at Loch Ness via a tunnel. These three power stations were built underground for environmental reasons. The control centre for the the entire scheme is at Fort Augustus. The total output capacity is 114MW. The scheme was built between 1949 and 1962.

Information from NRHE catalogue number WP007424 compiled by George Walker in 2005.