The Gosford Beaches Coastal Zone Management Plan (CZMP) contains an action to progress a long-term solution for Wamberal Beach erosion. The CZMP outlines a preferred protection solution (terminal protection structure) and the technical studies needed to inform further decision making, but it does not provide for the delivery of a seawall and sand nourishment.
On 29 January 2019, Central Coast Council resolved to work with the NSW Government to progress designs for a terminal protection structure (seawall) at Wamberal. Manly Hydraulics Laboratory (MHL) were engaged to complete coastal assessments and develop concept plans for a long-term solution for Wamberal Beach in May 2020.
Following the July 2020 storm event which saw the emergency response place 2,400 tonnes of large rocks, over 2,000 tonnes of rock bags and 4,000 tonnes of sand along Wamberal Beach, the NSW Government Wamberal Seawall Advisory Taskforce was set up to provide technical advice and assistance to Council in progressing a long-term solution for Wamberal.
There are many technical, financial, social and environmental complexities that need to be worked through to develop the long-term solution. Council understands that the best coastal erosion management solutions are developed when state and local governments, residents and the broader community work together.
Council has engaged the Wamberal and broader Central Coast community throughout this project.
Frequently asked questions
Why is Council investigating options for a terminal protection structure (seawall) and sand nourishment Wamberal Beach?
Wamberal Beach has a long history of coastal erosion, with beachside infrastructure exposed to impacts from coastal storms.
The Gosford Beaches Coastal Zone Management Plan (CZMP) outlines a terminal protection structure (seawall) and sand nourishment as the preferred course of action for managing identified coastal hazard threats at Wamberal Beach.
A technical study was progressed to provide options to more sustainably manage the erosion threat over the longer-term. Council looked at options to improve the community access and beach amenity condition, as part of the long term solution.
Who recommended a terminal protection structure (seawall) and sand nourishment for Wamberal Beach?
The terminal protection structure (seawall) and sand nourishment have been recommended by experts as a preferred erosion strategy at Wamberal Beach for several decades.
In the mid-1990s a Coastal Processes Study (PWD, 1994) and Coastline Management Plan (WBM, 1995) detailed the nature of the erosion issue and recommended either ongoing sand nourishment or a terminal protection in the form of a seawall. “a terminal protection structure in the nature of a buried rock revetment is to be designed and constructed to the satisfaction of Council and NSW Public Works, such construction to occur as soon as practicable and in an orderly, co-ordinated manner”
In the late 1990’s a range of coastal protection options were proposed by WRL (1998) for Council. A ‘Seabee’ seawall, spanning lagoon to lagoon, was designed and modelled in detail.
An Environmental Impact Statement (EIS) for the coastal protection solution was finalised in 2003 by MHL, which found that a seawall with periodic small-scale sand nourishment was acceptable. Council adopted the EIS for the seawall and sand nourishment solution in 2004. Funding however could not be secured and the approved protection works did not progress further.
Most recently, Council investigated the erosion issue and what to do about it, through a Coastal Hazard Definition Study (CHDS, 2015), a Coastal Zone Management Study (CZMS, 2017) and the preparation of a Coastal Zone Management Plan (CZMP, 2017). The Gosford Beaches CZMP outlines actions to address the erosion risks at Wamberal Beach. Sand nourishment and a terminal protection structure (seawall) was again determined to be the best solution to the long standing issue.
What is the Gosford Beaches Coastal Zone Management Plan?
The NSW Government has laws in place that guide how the NSW coastline is managed.
Coastal Zone Management Plans (CZMPs) identify coastal management issues and the actions required to address these issues.
The Gosford Beaches CZMP was prepared in line the state government legislation, and in consultation with the Central Coast community. The plan was certified by the Minister for the Environment in May 2017 and identifies several key management actions for Wamberal Beach, including:
- TW11: Terminal protection- Council to action review, design and funding of terminal protection structure for Wamberal
- TW14: Investigation of sources of sand and determination of the feasibility of beach nourishment for Wamberal Beach
- TW15: Beach nourishment coupled with a terminal revetment to increase the buffer against storm erosion.
Were the community consulted through the CZMP?
The community were consulted as part of the Gosford Beaches Coastal Zone Management Plan (CZMP; 2017), and preceding Coastal Zone Management Study (CZMS; 2015). A CZMP Community Engagement Strategy was developed and endorsed by Council in November 2013, this document guided consultation throughout the CZMS – CZMP processes.
Community consultation included:
- public exhibition of draft documents (CZMS, CZMP)
- CZMS - targeted community presentations to discuss potential management options for each study area, including Terrigal/Wamberal (2015)
- community drop-in sessions (include at Terrigal SLSC; 2015)
- public notices
- promotion via local newspaper.
In addition, workshops were held with the Council’s Catchments and Coast (advisory) coastal sub-committee established at that time.
What is the role of the Wamberal Seawall Advisory Taskforce?
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 was appointed as the Chair of the Taskforce with Council’s CEO, Member for Terrigal Adam Crouch MP, representatives from the Department of Planning, Industry and Environment, and Council’s appointed project manager.
The scope of the Taskforce was ‘advisory’ in nature. The Taskforce meets on monthly basis. More information on the Wamberal Seawall Advisory Taskforce is available on our website.
What is the MHL coastal engineering and economics study?
In May 2020, Council engaged Manly Hydraulics Laboratory to prepare concept plans for a terminal protection structure (seawall) and sand nourishment solutions for Wamberal Beach. The study included:
- literature review, to take stock of what is known and identify any information gaps
- coastal protection assessment, to determine sand movement, beach behaviour and impacts/opportunities around public access and amenity
- concept design options for a terminal protection structure (seawall) and sand nourishment, and potential seawall alignment
- sand nourishment investigation to help maintain public beach amenity
- cost benefit analysis to guide development of possible funding models.
The results of these technical studies will allow Council and the community to make an informed decision on the best combination of protection and sand nourishment options for Wamberal Beach.
Who will decide if a terminal protection structure (seawall) and sand nourishment works program is delivered?
There are many stakeholders involved in this decision-making process including: Council, NSW Government, beachside property owners, interest groups and the broader community members.
It is important to understand that while sand nourishment coupled with a terminal protection structure (seawall) has been identified as the preferred long-term solution for Wamberal Beach, the Gosford Beaches CZMP does not provide for the construction of a seawall. Indeed, the solution is complex - requiring input and agreement from a number of parties.
There are many steps to work through before a long-term solution can be implemented at Wamberal Beach. Finding a solution that strikes the right balance is not straight forward. Technical, financial, environmental, social, legislative and land ownership challenges must be addressed.
There is no guarantee that all the factors required to facilitate the seawall and sand nourishment solution will be satisfied. However, in the absence of a long-term solution the risk of further erosion impacts will remain and the result will be continued emergency works which are costly and not designed for long term protection.
Was retreat (buy back) being considered?
Council has no planned retreat policy. The resolution of Council was to proceed with MHL coastal engineering and economics assessment, consistent with the Gosford Beaches Coastal Zone Management Plan:
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 looking into the costs of potential erosion solutions and potential funding models.
Any long-term solution must be technically feasible, legally permissible, environmentally and socially acceptable and financially viable.
Further information on Planned Retreat being onsidered as part of the Cost Benefit Analysis (CBA) is available in the “The Cost Benefit Analysis mentions planned retreat, is that a viable option?” FAQ listed on the technical studies page.
How would the terminal protection structure (seawall) component of the long-term solution impact the beach?
There is no simple answer to this question.
There are many different factors that determine if a seawall structure will interact with waves and the beach.
- Seawall location and alignment: The location of a seawall relative to the beach profile that moves back and forth over time is important. Did you know that seawalls located behind the active beach do not interact with waves under most circumstances? There are many seawalls that co-exist with healthy, high quality beaches. Manly, Bondi and Newcastle (main beach, not Stockton) are good examples of this situation.
- Type of seawall and its geographical footprint: In locations like Wamberal Beach sloping rock revetments typically interact with waves and beach more than vertical seawalls, which can be placed further landward on the beach. This is because the sloping structures take up more space on the beach. A range of seawall types were investigated for Wamberal.
The coastal engineering study looked at behaviour at Wamberal Beach and assessed coastal impacts from the proposed program of works, including the impact on public access and beach amenity both now and into the future. Climate change impacts were also considered.
Did you know that ad hoc protection works have been placed at Wamberal Beach for many decades?
From Terrigal Lagoon to the Wamberal Surf Life Saving Club, the beach is backed by rocks, building rubble and other works. These materials have been placed in front of the erosion scarp by various entities since the 1970’s.
When Wamberal is in an eroded state, the ad hoc protection materials interact with the waves. When the beach system naturally recovers (builds out) over time, the rock and rubble become buried. A properly designed and constructed seawall would interact with the beach in a similar way, but in a more effective and less hazardous manner.
Replacing the ad hoc coastal protection works, with a properly designed and constructed seawall that improves beach access and amenity is one of several broader community benefits a long term solution would deliver.
What is sand nourishment?
Sand nourishment involves placement of sand on a beach to combat against erosion and improve beach amenity.
Sand nourishment can involve placing small or large quantities of sand into a beach system. Sand can be delivered to the dry beach face or placed underwater in the surf zone.
The placement method is somewhat dependant on the method of how the sand is extracted elsewhere and transported to the beach.
Was sand nourishment being considered?
The preferred long-term solution for Wamberal Beach includes a sand nourishment program to ensure long-term outcomes for Wamberal Beach.
Sand nourishment requirements, resources and cost estimates can be found in the Stage 4 Sand Nourishment Report of the MHL study.
Has Council applied for funding from the $83.6 million available from the State Government’s Coastal Management Grants Program?
In August 2018 Council successfully lodged a grant application to the NSW Government to receive funding for the investigation and design phase of a preferred long-term (seawall and sand nourishment) solution. The application did not include construction of a seawall.
The coastal engineering and economics study was co-funded (50:50) through the NSW Coastal and Estuaries Grants Program.