Draft PPS18: Renewable Energy
Annex 1 Small Hydro Technology: The Intake
E7. The scale and nature of these elements depend on site conditions, and whether the scheme is low head or high head.
E8. The intake typically comprises a concrete or rubble masonry weir, up to 2 metres high, across the watercourse. A spillway ensures that the downstream watercourse is never totally deprived of flow, and a screen or trashrack prevents floating debris or fish from entering the pipeline. A valve or sluicegate is often incorporated, and where the watercourse has a high silt load, a settling tank may be required. The Department’s Environment and Heritage Service (EHS), Land and Resource Management Unit should be consulted regarding disposal of debris from the trashrack.