Potential waterway impact of jetties

• reduced wildlife around the jetty
• need to remove or damage caused to riparian vegetation during construction
• increased flows around piles leading to erosion

Assessment criteria

Impact of riparian vegetation

The location of the jetty should make best use of existing breaks in vegetation, to minimise the need to prune or remove vegetation.

If vegetation needs to be removed, as well as a works on waterways permit you will need to contact your local council to organise a planning permit.

Bed and bank stability

Piles and piers associated with a jetty can change the way water moves which can lead to bed scour and reduce the stability of the jetty.

Jetties should not be constructed on the outside bend of a waterway as this is where flow velocity is the greatest. To reduce the risk of bed scour, piers must be aligned parallel to the direction of flow and riprap (rock beaching) must be provided around the piers to mitigate local scouring

Handrails

As the jetty is likely to be below the 1% AEP flood level, any handrails should be designed to reduce the chance of trapping flood debris. Build up of debris can block the waterway and threaten the stability of the jetty.