Wamberal: Beachfront owners to pay for $25-40M seawall, report says

Beachfront property owners, who will most benefit from a seawall at Wamberal, will have to cough up between $25-$40 million to have it built, according to a new report. Read why here.

A seawall to prevent further erosion from huge swells at Wamberal will overwhelmingly benefit a small minority of beachfront property owners — and not the public infrastructure of Ocean View Drive or hundreds of homes behind the sand dune — according to a new report which recommends the minority foot the bill to have it built.

A report to tonight’s Central Coast Council meeting recommends council press ahead with its plans for a seawall and publicly exhibit the draft design requirements for a minimum of 28 days.

However, while taxpayers and ratepayers have so far picked up the tab for the tonnes of boulders and rock bags dumped at the toe of the receding sand dune following the July 2020 storms — and the subsequent studies to identify a more permanent solution — the report states it will be up to the landowners to fund the wall.

Taxpayers footed the bill for the emergency works but beachfront homeowners will pay for the wall according to the report. Picture: NCA NewsWire / Troy Snook

The report recommends that “responsibility for the design, construction and maintenance of the three sections of seawall … rests with landowners that benefit from the seawall”.

According to the report the owners of the 72 properties stretching 1.3km from Wamberal surf club to 1 Pacific St, next to the lagoon, could expect to fork out an average of about $350,000 to $550,000 each to fund the wall depending on the chosen design.

“The preliminary capital cost estimates in the report to construct the 1,300-metre-long seawall ranges from $25 million or $18,400 per lineal metre (for sandstone rock revetment) to $40.1 million or $29,500 per lineal metre (for tiered vertical seawall with promenade),” the report states.

Following the storms in 2020 council engaged Manly Hydraulics Laboratory to undertake a literature review of all previous studies, assess the sand movement, come up with preliminary concept designs and a cost-benefit analysis of each option.

Beachfront property owners will have to fund a permanent wall according to the report. Picture: NCA NewsWire / Troy Snook

This was largely done through a 50/50 funding arrangement from council and the state government.

MHL came up with five concept designs ranging from a basic rock revetment wall, similar to the emergency boulders placed at the foot of the erosion, through to a tiered vertical seawall with a promenade walkway.

The studies also looked at sand nourishment and which wall option required the most sand to maintain a usable beach.

Alarmingly the report to council states the studies into beach renourishment “highlighted a lack of viable sand sources” with most requiring further investigation.

MHL found of all the options, option three of a vertical seawall had the best cost benefit ratio followed by a vertical wall with a toe.

A tiered vertical wall with promenade, Option 5, has been identified as the most expensive but most beneficial design to all beach users. Picture: supplied

“For all options, the majority of benefit flows to the beachfront homeowners with the protection of private property at risk to coastal hazards,” the report states.

“Some additional benefit for Options 3-5 flows to non-beachfront homeowners with improved beach width. Option 5 (vertical wall with promenade) delivers a larger share of benefits to the general community in the LGA, via provision of a public promenade improving access along the beach (maintained immediately after storms when the beach is eroded) and attracting some potential additional beach visitation.”

The report found options one and two would require the most sand nourishment and have all but been written off as a result.

It found the remaining three options would need sand nourishment about every 10 years at an estimated further cost of about $316,650 a year or about $3.17 million a decade.