Coastal erosion

Long-term coastal protection

In May this year, Council engaged Manly Hydraulics Laboratory to prepare concept plans for a terminal protection structure at Wamberal to assist residents in implementing a long-term solution. This is part funded by Council and the NSW Government through the Coast and Estuary Grants Program at a total cost of approximately $400,000. It will include workshops with residents and key stakeholders and this work is expected to be completed later in 2020.

Council is also preparing Coastal Management Plans for the entire Central Coast coastline, in accordance with the NSW Coastal Management Framework.  These will be completed prior to the end of 2021. As part of that process, there will be significant consultation with our community to finalise those plans.

Wamberal Beach Terminal Protection

Wamberal Beach is a popular coastal location that is vulnerable to coastal storms. Council has been working with the State Government and the community on a long-term management solution to the issue for some time.

Council’s PDF icon Gosford Beaches Coastal Zone Management Plan (CZMP) prepared in consulation with the community and in line with State Government legislation, outlines a seawall and beach nourishment as the preferred course of action for identified coastal hazards threats at Wamberal. A coastal engineering and economics study is currently being progressed to provide options to more sustainably manage the erosion threat over the longer term. 

Following severe coastal erosion impacts that occurred in July 2020 Council undertook extensive emergency remediation protection works at Wamberal, in accordance with orders made by the Local Emergency Operations Controller under provisions of the State Emergency and Rescue Management Act 1989. These works are now complete and attention is now turning to progress a long-term solution to coastal erosion at the beach. The State Government has established the Wamberal Seawall Advisory Taskforce to help progress a long-term solution.

History of a seawall at Wamberal

  • In 2004, the former Gosford City Council after extensive research and public consultation processes, considered a buried terminal structure to be the preferred protective strategy at Wamberal.
  • The estimated cost of the seawall at that time, was approximately $23.3M. The former council applied, unsuccessfully, for funding for the terminal structure via various State and Federal grant programs. The seawall did not ultimately progress due to a lack in funding.
  • The Gosford Beaches Coastal Zone Management Plan was adopted by the former council in December 2015 and was certified by the Minister in 2017. This is the current plan for management of the Wamberal beachfront (and other coastal areas).
  • A cost benefit analysis in respect of the terminal structure identified in the Gosford Beaches Coastal Zone Management Plan was prepared by the then Office of Environment and Heritage in August 2017.
  • The Wamberal Terminal Protection Working Group was established in November 2017 to bring together all the stakeholders to progress discussion relation to coastal erosion at Wamberal Beach - representatives are Council staff, Department of Planning and Environment sttaff and two Wamberal residents.
  • A project working group was established in June 2018, to progress the Gosford Beaches Coastal Zone Management Plan across the whole Central Coast. •
  • Funding was provided by the State Government in December 2018, for preliminary investigations and design of the terminal structure.
  • In 2019, Council resolved to commence preliminary investigations and concept design works.
  • In May 2020, Council engaged Manly Hydraulics Laboratory to commence investigations and design work in respect of the terminal structure
Average: 1 (4 votes)

Is Council committed to installing a terminal protection seawall structure along the length of Wamberal Beach and if so, within what timeframe?

On the 29 January 2019 Council resolved to work with the State Government to progress designs for a terminal protection wall at Wamberal:

37/19 - That Council note the funding offer provided by the NSW Government for the Wamberal Terminal Protection and Sand Nourishment preliminary investigations and concept design.

38/19 - That Council request the Chief Executive Officer to commence the Wamberal Terminal Protection and Sand Nourishment preliminary investigations and concept design.

Council is currently working with the NSW Government’s Manly Hydraulics Laboratory to complete coastal investigations, concept designs, and coastal and environmental impact assessment work.

This work will include the following program:

  • Coastal processes study to determine sand transport and beach behaviour
  • Concept design options for a seawall and beach nourishment, and potential seawall alignment
  • Coastal and environmental impact assessment of a seawall, including impacts/opportunities around public access and amenity
  • Cost benefit assessment and benefit distribution analysis, to guide development of possible funding models

Some of the key questions this project seeks to answer include:

  • Technical: What type of seawalls could be built? Where would a seawall be located? Will beach nourishment occur? Where will the sand come from?
  • Financial: How much will the proposed program of works cost? How will the works be funded? Who will pay what?
  • Social: Will a seawall influence beach behaviour? If so, how often? Are any broader community benefits on offer beyond protection?

This coastal engineering study will ensure Council completes the Wamberal based actions in the CZMP. It will also allow Council and the community to make an informed decision on the best combination of protection and sand nourishment options for Wamberal Beach.

Will building the wall protect the community and what impact will it have on the beach?

A seawall to protect houses and property along Wamberal would be required to be designed and constructed to appropriate coastal engineering standards.

The environmental impact assessment for the development will also need to take into account the impact of a seawall on the environment and the community including the impact on public access and beach amenity both now and into the future. Consideration of the impacts of forecast climate change will also be required.

How much will a revetment or terminal wall cost?

At this stage it is not possible to speculate on the final cost of a complete seawall because it will depend on the type of structure, the final design, and its actual location. Depending on the type of structure and final design, a seawall may typically cost from $10,000 to in excess of $30,000 per lineal metre. By way of example, conventional rock revetments are relatively low cost, while stepped concrete seawalls are relatively high cost.

Who will pay for the wall?

A funding model is yet to be determined however those parties who will benefit the most from a wall will be the principal contributors and that is likely to include property owners, the State Government and Central Coast Council.

What is the Wamberal Taskforce? What is its role in a long-term solution for Wamberal Beach?

The NSW Government established the Wamberal Seawall Advisory Taskforce on 31 July 2020 to provide Council with support to implement a sustainable long term solution to coastal erosion issues at Wamberal Beach.  Dr Phil Watson has been appointed as the Chair of the Taskforce with Council’s CEO Gary Murphy, Member for Terrigal Adam Crouch MP and representatives from the Department of Planning, Industry and Environment. The Taskforce meets bi-monthly. In September, Council appointed a dedicated Project Manager to Taskforce to manage the long-term solution. 

Council has approved a wall for 6 houses at Wamberal. Can I submit a Development Application (DA) and build the same?

Any Development Application (DA) submitted will be considered on its merits under the relevant planning controls and certified CZMP.

Council was the respondent consent authority in proceedings before the Land and Environment Court, in respect of a development application that sought to construct coastal protection works at Wamberal. Those proceedings resulted in the Court granting conditional consent to that development application, following successful conciliation between the applicants and Council. Conciliation is a mandatory process for this type of appeal.

The consent issued by the Court includes a condition that requires the approved coastal protection works be removed, at the owners’ expense, if coastal protection works permitted by the consent are incompatible with a whole-of-bay solution for Wamberal Beach, as provided for in the adopted Coastal Zone Management Plan (CZMP). That is, the Court’s consent is not incompatible with the whole-of bay approach in the CZMP which was certified by the Minister in accordance with provisions of the Coastal Protection Act 1979.

Given the threat from possible storm damage to Wamberal property and infrastructure has been constant and persistent since the 1970s, why is the installation of a solution still not in place – why is it taking so long?

The solution is complex, requires input and agreement from a number of parties, and no funding model has previously been developed to implement the works. An agreed funding model is a central element to delivering a terminal protection seawall structure on Wamberal beach.

Council established the Wamberal Terminal Protection Working Group in November 2017 to bring together all the stakeholders to progress discussion relating to coastal erosion at Wamberal Beach.

The Working Group consists of Council staff, representatives from the NSW Government and two representatives from the Wamberal community.

The Working Group is currently working collaboratively on a number of issues including:

  • beach ownership matters (some land between the residential property boundary and high water mark may be privately owned)
  • reviewing existing geotechnical information to establish the underlying ground conditions
  • preparing a detailed Project Plan to govern progress
  • reviewing existing on-ground structures including protection walls and other structures
  • similar ownership/logistics issues that apply on the Northern Beaches / Collaroy areas
  • survey of the varied existing structures in place elsewhere
  • legal requirements should a wall be built (DA’s, covenants etc).

What can residents do to protect their homes while a permanent solution is being looked at?

No protection works can be carried out without prior development consent. The State Government recently introduced legislation which only allows Government Authorities to carry out emergency protection works.  The appropriate course of action is to lodge a development application with Council which will be considered on its merits.  More information on coastal protection works can be found in this factsheet provided by the State Government.

Next Steps

  • Land Survey and Geotechnical investigation
  • Concept Design Options Assessment
  • Development of Minimum Engineering Design Requirements
  • Coastal Erosion Policy for adoption by Council
  • Environmental and Coastal Assessments to support the Development Assessment Process
  • Update of Cost Benefit Distribution Analysis
  • Funding Model
  • Community Consultation and Workshops

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Last updated : Thu 8 Oct 2020