Project Name: Warilla Beach Seawall Renewal
Project Address: Warilla Beach. Tom Strong & Leggett Park
Project Budget: Overall project costs are approximately $10M. This project is proudly supported by NSW Government’s Coastal and Estuary Grants Program.
Council has been successful in securing a State Government grant via the Coastal and Estuary Grants Program for the reconstruction of the ailing seawall, which was first built in the 1960s. The 930 metre wall is eroded and unstable, and as a result will be rebuilt to modern engineering standards to address coastal erosion and public safety concerns.
The renewal of the seawall was included in the Council's Coastal Zone Management Plan in 2018.
We anticipate construction will take about 12 months to complete. This project will be subject to weather and coastal conditions that may impact the timeframe.
Yes, the construction of the new wall will typically be completed in 20-meter sections. The restoration of landscaping and concrete footpaths will be completed in larger sections, likely in two or three stages as works progress from south to north.
The closure of current beach access points will be staged so that disruption to the public is minimised. The aim is to complete the new stairs at Bucknell Crescent and the Beach Access Ramp extension early in the project. While these access points are closed, existing access points at the south end of the beach and at Tom Strong Reserve will be maintained. Any informal access points to the beach will be left untouched until construction of the new wall progresses to those locations.
There will be changes to the use of the pedestrian shared path along Warilla Beach, however the nature of any disruptions will vary depending on how much space is available in each area. The reconstruction of the wall will be completed in small sections, typically around 20m long. The section of shared path adjacent to a work area will have to be closed off as part of the working area due to restrictions on space. However, a temporary diversion will be in place around the site fencing, with appropriate warning signage, to allow pedestrian access past the work area.
There may be some areas at the northern end of the site where space may become so restricted that it will not be possible to maintain a safe pedestrian diversion. If this is the case, diversions will be in place and pedestrians with either have to walk along Little Lake Crescent between Tom Strong Reserve and Leggett Park, or along the beach.
Yes, access to the water will be maintained for the public. During work, there will be heavy machinery and truck movements along the beach to each work area, as illustrated below. Due to the limited width of the beach, construction equipment will be travelling as close to the sea wall as possible, to keep above the high tide mark and out of the water. From time to time, we may have to request the public to relocate, should they be set up on the beach within our limited access route. However we remind people to always swim between the red and yellow flags.
Six parking spots on Little Lake Crescent will be closed at the entrance and exit to the site compound at Tom Strong Reserve as illustrated below. There may be some intermittent use of the end of Bucknell St for access to construct the new stairs and access ramp extension.
Construction works may take place from Monday to Friday 7 am to 6 pm, Saturday 7am to 2pm with no work scheduled on weekends or public holidays. This project will be subject to weather and coastal conditions that may impact the time of construction.
The truck haul route to and from the site compound is illustrated below.
Yellow – Entry / Red - Exit
Council has identified some locations along the seawall where it is possible that asbestos containing materials will be encountered. As a result of this, Council has amended the design of the southern section of the wall to minimise the risk of disturbing this material. This reduces the risk of disturbance of asbestos containing materials. Construction of this section of the wall will be supervised by a qualified hygienist to ensure that Safety Regulations are met and that there is no risk to the public, workers or the environment.
Images - Existing seawall and final design
The Warilla Seawall is 930m in length and was constructed as an ad-hoc response to storm events in 1966 that threatened private properties and sewerage infrastructure. Subsequent maintenance to upgrade and extend the seawall occurred following storms in 1974, 1975 and 1978. Since 1980, maintenance works have tended to involve additional rock fill and strategic placement of rock boulders to stabilise the seawall. The wall sustained extensive damage in 2016 due to an east coast low. Since then, council has been periodically repairing damaged sections of the wall.
When construction of the new wall is finished it will provide improved safety for the high number of community and visitors that frequent the beach and use the shared path. It will also provide coastal protection to this section of the shoreline.
The current seawall which protects land side assets, does not meet modern engineering standards. The existing wall requires regular maintenance after storm events to repair damaged sections and make the area safe for the public. In addition, current rock is not suitable in the long term as it slowly breaks down under coastal conditions.
The renewal of the seawall was included in the Council's Coastal Zone Management Plan in 2018.
Seawalls and revetments are structures that run parallel to the shore line, with the primary purpose of providing protection from erosion. The difference between revetments and seawalls is that generally a revetment is less vertical than a seawall.
The existing structure on Warilla beach is technically a revetment, the new structure is also a revetment. However, historically the existing structure has been called a seawall.
So it is easily recognisable by the community, the new project has been called a seawall renewal.
In 2020 Council engaged a consultant to prepare a Cost Benefit Analysis to inform its decision making on the future of the existing revetment. Some of the options considered were:
- Maintain, repair and remove the existing revetment
- Maintain, repair and make safe the existing revetment
- Construct alternative designs including an engineered revetment.
- Beach nourishment
It was determined that Council would proceed with designing and constructing an engineered revetment.
Overall project costs are approximately $10M. This project is proudly supported by NSW Government’s Coastal and Estuary Grants Program.
Two options were considered for the new design: rock revetment structure and an engineered wall. An engineered wall was found to exacerbate beach erosion. The current design, rock revetment structure, was selected as it is cost effective and minimises beach erosion, through its passive design that absorbs wave action.
The existing seawall has two formal sets of stairs and an emergency access ramp. It also has a number of informal beach access points.
The seawall upgrade will provide improved amenity and safety with a minimum of three formalised beach access points, plus an emergency access ramp, therefore increasing the current number of formal beach access points.
Council has worked with its designers to minimise the encroachment of the new wall onto the beach as far as possible. We have added an indicative image of where the new seawall will be relative to the existing wall
The Warilla Seawall Project is one component of Council's plan to manage Warilla Beach. Future actions related to sand nourishment and dredging activities are being considered within Council's existing Shellharbour Coastal Zone Management Plan (CZMP)
Two options were considered for the new design: rock revetment structure and an engineered wall. An engineered wall (vertical seawall) was found to exacerbate beach erosion through reflection of wave energy. A rock revetment structure, was selected as it is cost effective and minimises beach erosion.
Although we love the concept of a Living Seawall, Warilla seawall will be above the high tide mark (out of water) for the majority of the time, therefore it would not be functional in this location.
Due to the location of the project, there will be environmental impacts. A Review of Environmental Factors (REF) has been completed to provide advice on how to manage the environmental impacts.
The Review of Environmental Factors (REF) for Warilla Seawall is now publicly available on Let’s Chat. Click here to view
Like the existing wall, the new seawall will be constructed with large rocks. However, the rocks will be individually placed to interlock with one another. This means that there will be less gaps between the rocks. The rocks on the outside of the wall will be placed to form a more even slope. Part of the wall will be backfilled with sand and part will be exposed rocks. The amount of exposed rock will vary depending on the surf conditions and will change over time.
The new wall will be constructed from 3 different size ranges of rocks. The first layer will be smaller rocks 25mm to 300mm in diameter. The second layer will be rocks 100kg to 650kg. The outer, visible, layer will be rocks 2t to 4t. The type of rock used will be selected to ensure it does not breakdown in the marine environment.
The southern section of the wall will be encapsulated within the new wall. The new wall will be placed over the top of the existing wall in this location. The northern section of the wall will be removed to make room for the new wall. The rocks that are removed will either be reused in the new wall, if they are suitable, or disposed of.
As part of this project, landscaping will be completed at the crest of the seawall. The plant species selected for this have been chosen by coastal experts because of their ability to stabilise the dune environment. Various grasses and low lying shrubs have been selected. Norfolk Island Pines were not selected for this purpose.
The project scope for the Warilla Seawall renewal is to rebuild the seawall to provide coastal erosion protection, asset protection, improved amenity and safety for all users.
Footpath upgrades, shared path lighting, extra seating and amenities have not been included in the project scope.
Unfortunately this location is outside the scope of this project.
However, if you would like this enquiry to be investigated further, please log an eServices request for our or contact Council’s Customer Service team on 4221 6111.
Vote for Stairs
Label - Red line indicates the average position of the toe (bottom) of the proposed rock seawall
Description – The new seawall has been designed to modern engineering standards. This has resulted in it being thicker and having more interlocking parts than the existing wall. As a result, it takes up additional space on the sand relative to the existing wall.