RichardLyons

By RichardLyons

Glenlochar Barrage

Glenlochar Barrage is a structure on Loch Ken and is a major part of the Galloway Hydro-Electric Project. It is designed to regulate the water level in the major part of the loch to the north and still allow unrestricted flood outflows towards the River Dee to the south.
Loch Ken is a 14km-long body of fresh water that is supplied by the Black Water of Dee and the Water of Ken at the northern end, and empties into the river to the south. It was selected as the regulating reservoir for the Galloway Hydro-Electric Project, and to increase its originally limited capacity, the barrage was constructed across it at Glenlochar, just north of the B795 road bridge.
The barrage is 103m long and 10.7m high overall. It raised the water level of Loch Ken by approximately 1.8m. Its gates can be operated either manually, by electric push-button control from the steel overbridge above the barrage, or by remote control from Tongland Power Station (NX695535). Downstream of the barrage structure, the loch bed is protected from scour by a concrete apron and pitched stonework.
There are six lifting gates, three on either side of a central 6m wide fish pass. Eight reinforced concrete piers separate the gates and the pass. The fully balanced free-roller gates each have a clear span of 13.7m, three gates are 3m deep and the other three are 2.7m deep to accommodate river bed contours. The gates weigh 11.2 tonnes each and were delivered to site fully assembled. When closed they rest on steel sills embedded in concrete.
Water levels in Loch Ken are normally within the range 44-45m above sea level, when the outflow through the barrage is restricted to the volume required by the generators at Tongland Power Station, since the small reservoir behind Tongland Dam (NX701545) is not sufficient for the station's needs. If the loch's water level rises above 45m, the barrage gates automatically lift clear and allow water to dissipate.
The barrage was completed in 1934 and automatic noise monitoring equipment was installed in 2009. Loch Ken and the Glenlochar Barrage are with the River Dee (Parton to Crossmichael) Site of Special Scientific Interest, and also the Loch Ken & River Dee Marshes Special Protection Area and Ramsar Site.

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