Clarence River erosion study

In 2014 the University of NSW’s Water Research Laboratory was commissioned by Transport for NSW, Clarence Valley Council and North Coast Local Land Services to conduct an assessment along several sections of the Clarence River to report on the status of riverbank erosion, the causes of erosion and to suggest remedies to ensure the long term environmental sustainability of the river.

Following the report’s release, a multi-agency committee was formed with members from Transport for NSW, Transport for NSW, North Coast Local Land Services and Clarence Valley Council. This committee developed a 12-point Management Action Plan. This Plan seeks to balance the environmental needs of the river while ensuring boaters, businesses and local residents can enjoy the river for years to come in a sustainable and responsible manner. The actions were projected to be in place for a period of two years from September 2015 to September 2017.

In October 2016, the Committee was briefed on the details of a series of remediation works needed to stabilise key sections of the riverbank, this work would address two of the proposed actions. The committee subsequently decided it was necessary to extend the Management Actions for a further three to five years, to enable these riverbank works to stabilise.

A public meeting was held in November 2016 to inform the community of the extension of management measures and discuss progress on the issue.

In November 2017, another community meeting was held to update stakeholders on progress, emphasising the land-based work that was about to be trialled.

Boating restrictions have remained in place and attention has now turned to the land remediation work. We have conducted a trial, involving a barge and materials at two locations along the river. This trial tested the logistics and assumptions in the plan and evaluated timing, barge movements and the accessibility of the banks themselves.

Originally scheduled for May 2018, the trial was conducted in August and was a complete success. We now know the strategies and timings we had planned for the bank remediation work were sound and we are now focused on finalising agreements with the remaining landholders for the work to continue on their land.

A number of exciting initiatives are being explored in relation to the project, including the development of a very tough species of vegetation, which, if testing is successful could have impacts on erosion management strategies throughout the state.

The Committee met again in August to review the trial progress and identify next steps.

There was a public meeting in late-September to inform the immediate community of progress. And a community update is planned for early December to inform the wider community of progress. Local varieties of tree saplings and other vegetation have been identified to stabilise the river banks and help blend the larger material work into the natural environment. Once a detailed scope of work on the riverbanks has been finalised, the number and specific type of vegetation will be known.

• What are the boating restrictions?

  Restrictions are now in place against wakeboarding, wake surfing, aquaplaning and using an additional ballast in the new ‘no slow-tow’ zones in the Clarence River for a further three to five years from 1 September 2017 at:

  • the areas between Rogans Bridge and Moleville Rocks
  • the northern channel between Susan Island and Grafton.
• Why 'no slow-tow' rather than 'no towing' restrictions?
  As the restrictions apply to most circumstances where heavy wash is generated, a general prohibition on waterskiing is not considered necessary due to the preference for smooth water and the comparatively lower level of wash generated.
• Why are the new restrictions in place?

  Recreational activities such as wakeboarding have the potential to cause damage to the river environment and by restricting this activity Transport for NSW aims to assess the impact reducing wash will have on the riverbank.

  The Management Plan was developed following extensive community consultation and in consideration of scientific evidence established by the University of NSW Water Research Laboratory (WRL). The WRL identified parts of the Clarence River riverbank as sensitive to erosion and where high-wash boating activity is likely to be a contributing factor.

  With consideration of the scientific evidence and after extensive stakeholder and community consultation, the new boating restrictions were determined as part of the Clarence River Erosion Management Plan.

  The Management Plan aims to balance the environmental needs of the river while ensuring boaters, businesses and local residents can enjoy the river for years to come in a sustainable and responsible manner.

• Will the new restrictions affect aquatic events?
  The new restrictions will not affect aquatic events such as the annual Grafton Bridge to Bridge race. As aquatic events are held infrequently they are not considered to have a substantial or ongoing impact on riverbank health.

• November 2018 community update

  The latest news on the project.

• August 2015 Clarence River erosion management plan

  Improved management of boating wash and riverbank erosion.

• December 2014 Water research laboratory report

  Riverbank Vulnerability Assessment using a Decision Support System: Clarence River (Rogans Bridge to Ulmarra).