Run-of-River Hydro » The environment
Aesthetics
Historically, hydro schemes have been associated with dams, reservoirs, over-ground pipelines and high-voltage transmission lines. All can be prominent in the landscape. None apply to run-of-river schemes...
For intakes, at most a stone-faced weir about 1m high above river bed level is needed. This causes a slight local rise in river level. The risk of flooding is not increased. The purpose of the weir is to create sufficient water depth to ensure that air does not enter the pipeline. Intakes can be visible from certain vantage points during low flow but are designed to have very low visual impact.
Pipelines are usually buried. Local exceptions to this sometimes occur, for example where a small ravine has to be crossed. In such cases the pipeline can be used as a structural support for a walkway across the river (photo).
Powerhouses are usually hidden, either in existing converted buildings or ones designed to fit in with the local landscape and architecture (photos). Powerhouses often resemble traditional small farm buildings with local stone-faced walls and slate roofs. In certain situations, our assessment has shown that an underground structure is preferable, for example in a steep river bank.
The electrical output from most run-of-river hydro schemes can be carried by the common three-wire overhead line widely used for local distribution. These operate at voltages in the range 11-33kV. It is often possible to connect schemes directly into these lines and, since this infrastructure is usually already in place, visual impact is minimal. In the event of the requirement for a new line, modern technology allows burying of cables with ease, thereby eliminating almost completely any visual impact.
Waterfalls are aesthetic features and often attract tourists. Abstraction regimes are calculated to ensure no appreciable change to the visual prowess of any waterfall located between intake and outfall.