Study Figures A and B, which show details of the Loch Glencairn Reservoir and Dam scheme in Scotland.
Examine the possible advantages and disadvantages of the reservoir and dam scheme. You must use evidence from Figures A and B in your answer.
Figure A
Figure B
Photograph and Fact Sheet of Loch Glencairn Dam
A photograph showing a 45-metre high concrete gravity dam with water cascading down a stepped spillway. A small, modern hydroelectric turbine house sits at the southern base of the dam with power lines running up the hillside.
Fact Sheet:
Reservoir Area: Flooded 6.8 km2 of the valley floor.
Displacement: 30 residents of the farming hamlet of Inverglen were relocated; the historic 18th-century stone bridge and chapel were submerged.
River Regulation: The dam regulates downstream flow of the River Cairn, significantly reducing peak discharge during high-intensity winter rain events in the town of Cairnmouth (25 km downstream).
Energy Production: The turbine house houses a 4.0 MW4.0\text{ MW}4.0 MW small-scale hydroelectric system, supplying clean electricity to the local grid.
Ecology: Conservationists report that the physical barrier prevents the upstream migration of sea trout and alters the natural gravel transport required for spawning downstream.
