A Proposed Seawall Threatens A Beloved Australian Beachie

For decades houses along Wamberal’s shore have faced the threat of being washed into the sea. Two hours north of Sydney’s hustle and bustle, Wamberal is a coastal suburb home to hundreds, if not thousands, of surfers who’ve cut their teeth along it’s two-kilometre stretch of sand. You would be hard pressed to find a surfer who grew up on the Central Coast who doesn’t have at least one memorable session here – I know I have a few.

While the issue of erosion has been on the minds of home owners at Wamberal for years, the recent spate of large swells reiterated the fact this issue was urgent and would not resolve itself. Thirty metres of beach was washed away in mid-July after an East Coast Low and 18 of the 60 houses along the shore were indefinitely evacuated  as a result. 

One proposed solution – supported by many of the aforementioned home owners – is to construct a seawall. There is however vocal opposition to the proposed wall, many of whom have joined the Facebook group Wamberal Beach Save Our Sand; a group which is also angered by the exclusion of other local residents and the Surf Live Saving Club from initial discussions about a wall.

In short, while the majority of the 60 homeowners along Wamberal’s waterfront are in favour of a wall, there are thousands of other locals who are opposed. Both groups want to reduce erosion and maintain Wamberal’s essence*, their disagreement is over the best method of doing so. 

A report by Marsden Jacobs outlines eight different options. Option one is maintaining the status quo, options two to seven involve various types of seawalls, and the eighth option involves a Planned Retreat which would “manage the duration, type and intensity of future development in the coastal hazard area”. 

“[N]one of the engineering options considered provided a net public benefit for the local community.” The Guardian’s summary of the report read. “This is because all of the seawall options would result in the loss of beach areas, and without sand replenishment the beach would quickly disappear, with significant costs to the local tourism industry.

“[I]t was not clear which seawall option would lead to the fastest loss of the beach but all would result in an unusable beach by 2064, without a major sand replenishment program.”

According to the report by Marsden Jacobs, some of the 60 homes immediately threatened will be protected by a seawall, but in the long term more homes will be endangered by rising sea levels in both Terrigal and Wamberal lagoon. 

“The CBA shows that of all the options considered, Option 8 is the only option that will provide a net gain in economic welfare for the residents of the Central Coast.” The conclusion of the report reads. “The speed with which the beach will be lost will vary with the type of seawall involved. The council proposed rubble mound revetment (Options 2 and 3) will result in immediate loss of most of the beach in winter. Vertical seawall designs (Options 6 and 7) only have a two to three metre footprint, but their design means that the rate of sand erosion is faster than with a rubble mound revetment.”

On a whole, those served to benefit from a potential seawall are those homeowners on the waterfront. When the entire community is taken into account, all reports found there to be no net benefit for the greater community. Furthermore, if the majority of the sand will be swept away, there is little hope for Wamberal’s sand banks and the waves which break upon them to be unaffected. Locals have reported that makeshift concrete barriers are already influencing wave quality at the beach.   

Despite this, the local council seems to be leaning towards the side of the seawall, with additional studies being undergone at the expense of the taxpayer; for example, a study being run by Manly Hydraulic Laboratory will cost the Central Coast Council and state government upwards of $400,000. If the seawall were to be built, estimates at the production cost are in the tens of millions. 

Option 8 may involve buying back the homes and lands of the current owners at threat – a cost itself which would be in the hundreds of millions if all 60 homes were to be re-purchased – and have a Planned Retreat. The council had the opportunity to do this in the 70’s after previous mass erosion events, but decided not to, instead opting for continued development.

The issue of erosion is going to be a costly affair for councils and governments around the world in years to come as sea levels rise and storms worsen as a result of global warming. If one thing is clear it is that a decision needs to be made, and preferably one which is directed by the science and benefits the community as a whole – not just a handful of wealthy and influential individuals. 

*A more sceptical view would be that the wealthy homeowners are interested in the immediate impact on themselves and their houses rather than the beach/community as a whole.