Key features of a small hydro scheme include:
- a hydraulic 'head' - vertical distance from water source to the turbine.
- a water intake above a weir or behind a dam
- a pipe or channel to take water to the turbine
- a turbine, generator and electrical connection
- an outflow, where the water returns to the watercourse
These elements raise a number of important planning issues and planning permission will usually be needed.
The elements of a small-scale hydro electricity scheme create potential impacts on:
- landscape and visual amenity
- nature conservation
- the water regime.
Some form of environmental assessment is essential when it comes to applying for planning permission and environmental licenses.
Under the Town and Country Planning (Assessment of Environmental Effects) Regulations 1988, the planning application for any development that the planning authority considers likely to have a significant impact on the environment must be accompanied by an Environmental Statement.
This document provides an assessment of the project’s likely environmental effects, together with any design, construction, operational and decommissioning measures that are to be taken to minimise them.
It would typically cover such issues as flora, fauna, noise levels, traffic, land use, archaeology, recreation, landscape, and air and water quality.
It should be noted that the Environment Agency must also be consulted about water extraction licences because the water is not owned by the landowner.