In the far northwest of Scotland at Glen Strathfarrar, remote Loch Monar is held in this valley by an unusual double curvature concrete arch dam—making the facility unique in Britain. Deer and wild goat roam on the surrounding land, which is privately owned and managed.
As at many locations, the hydro board had to overcome opposition to build the dam that flooded this valley.
"It did change the shape of Scotland; you can't get away from that," says Reeves. "But it was done in a way that blended in with the environment."
Similar conflicts arise wherever hydropower plants are planned around the world, as corralling water for power can destroy marshland, other sensitive habitat, and even villages. For the largest hydroelectric project in the world, Three Gorges Dam, China relocated more than 1 million residents.
(Related: "China's Three Gorges Dam, by the Numbers" and "Pictures: Huge Jets Shoot From Dam During China Floods")
The upheaval for residents, by contrast, was minimal in the rural and rugged Scottish Highlands, with 25 percent of Great Britain's land but only 3 percent of its population.
At Loch Monar and the associated power stations, just as at all of the hydro plants in the Scottish Highlands, government regulations require that SSE maintain certain levels of water flow so that rivers do not run low. This compensation water allows fish to move, breed, and feed, and maintains a flow of water throughout the landscape. It comes at an energy cost. "That means sometimes we are not able to generate," says Reeves.
He says when rainfall is extraordinarily heavy, the hydro system also will allow water to spill over the dam to minimize the impact of local flooding, as long as it doesn't create a problem further downstream. "We have to be a neutral player," he says. "But if there is a way to safely operate to prevent flooding at the expense of generating power, we will do that," he says.
(Related: "Lessons from the Field: Patuca River, Honduras")
(Related: "Resurgence of Large Dams Threatens Tribal People, Report Says")