Deflectors/groynes/croys
Deflectors/groynes/croys
Artificial structures that are installed part way across the channel to deflect currents away from eroding banks or help create more in-channel habitat diversity. Most often installed flush with the bank toe to deflect flow from one side of the channel to the other, but may be also installed in mid-channel. Can be made from a variety of materials, including rocks, logs, sheeting, gabions, wooden/heather hurdles, posts and wire, and occasionally wooden stakes.
Major: extends across >=20% of channel width. Includes completely collapsed weirs that no longer influence water levels upstream.
Major deflector/groyne/croy
Intermediate: extends across 10-20% of channel width.
Intermediate deflector/groyne/croy
Minor: extends across <10% of channel width.
Minor deflector/groyne/croy
If it is clear that these structures have been installed for habitat/fishing enhancement, note in Section O. It is recommended that all deflectors (including minor ones) are photographed since their impact/purpose varies greatly according to their height and material, not just their extension across the channel.