The Wicked Problem of the Collaroy Seawall

Stu Nettle picture
Stu Nettle (stunet)
Surfpolitik

“It’s a wicked problem they’ve got, in the true sense of the word.” 

So says Brendan Donohoe of the conundrum facing Northern Beaches Council in relation to the Collaroy beachfront. Donohoe has presided over the Northern Beaches branch of the Surfrider Foundation for over twenty years, and he’s currently livid with the council.

The reason is the appearance of a concrete seawall along a stretch of beach between Wetherill Street and Stuart Street, which both run off busy Pittwater Road. The area has been slowly receding due to storm damage - there’s evidence of erosion dating back to the 1920s - while at the same time being intensely researched by coastal geographers.

It’s also been the focus point for opposition to coastal development; an abject lesson about what results from bad policy. The lessons, it would seem, are still being learnt.

Drone footage over Collaroy after the June 2016 'Black Nor'easter swell' (Photo: UNSW Water Research Laboratory)

“I saw the construction going in,” says Donohoe of seeing the area cordoned off earlier this year, “and thought they were building rock revetments. Angus Gordon, an engineer with fifty years experience in coastal engineering, assumed the same.

“My understanding was that council were looking at a rock revetment as they'd given approvals to a couple of other DAs for rock revetments,” says Gordon.

Both Donohoe and Gorden were correct, up to a point: The construction began with concrete piles sunk six metres below sea level, protected by a rock toe. However, the work then continued skyward with a seven metre vertical concrete wall on top of the foundations.

The finished work is 100 metres long by 13 metres high. The seven metres protruding above sea level is vertical, even going beyond vertical for the final metre to prevent wave overtopping.

“It’s brutalist engineering,” says Gordon frankly. “It’s like stepping forty years back in time. We’ve long known that putting a hard structure...particularly a hard, vertical structure, on the beach increases erosion.”

Northern Beaches Council puts up the big don't argue (Photo Craig Brokensha)

Both Brendan Donohoe and Angus Gordon, and other people Swellnet spoke to, admit to being blindsided by the construction. They can be excused as they thought they’d be informed before any such works took place, as per the 2016 Coastal Management Act.

The Act was introduced by Rob Stokes, the NSW Minister for Planning and member for Pittwater. Among many objectives, it outlines how people living in threatened property might defend their homes. It also enshrines a process of community consultation before a council adopts any coastal programs.

At this point, no-one can say if any consultation occurred, though the cynical view is council ticked the box by distributing flyers to the immediate neighbours, all of whom would want similar works built to protect their properties.

“I get informed about a proposed bike lane two suburbs away,” questions an aghast Donohoe, “but I hear nothing about construction abutting a nearby public beach?”

Gordon was equally puzzled: “I guess people become frustrated with the bureaucratic process and find ways of not involving the public. The legacy of that approach will be something future generations will have to live with.”

The concern about the seawall stems from the dynamic nature of sand dunes and how introducing a hard structure onto the foredune interferes with the natural state of flux. During periods of low swell energy, sand accumulates on the beach, widening the profile and forming a natural barrier for when storms and large waves erode the coastline.

The process is cyclical, however short-sighted development upon the foredune, built during times of a wide beach profile, impedes the system. Rather than a natural ebb and flow of wave energy, a hard structure increases reflective energy and turbulence, making it difficult for sand to settle and accrete. Beaches with hard structures can return, though it takes longer, and rocks and concrete in the wave zone also make for a dangerous combination.

An increase in storm activity - particularly from the east and north-east, as has been proposed by Associate Professor Ian Goodwin - and the looming threat of sea level rise are X-factors for East Coast beachfront development.

Collaroy has a long history of property erosion, yet a century after it was first documented there’s no consensus about how it should be managed. In the early 2000s, Warringah Council (as it was then known, it’s since been amalgamated with Manly and Pittwater) spent $6 million dollars buying three properties. Though with 80 properties at risk, and coastal real estate prices at a premium, they gave up on that approach in 2007.

In a 2007 story for the Sydney Morning Herald, both Rob Stokes and a spokesperson for Warringah Council admit buyback isn’t feasible and that other means of defence would be necessary, such as dune reconstruction, revegetation, and sand nourishment. Seawall construction isn’t mentioned.

Perhaps the omission was because in 2002, protestors, led by Brendan Donohoe and Surfrider Foundation founder Tom Kirsop, formed a “line in the sand” stretching from Collaroy to Narrabeen opposing the construction of any seawalls. The activism of Tom Kirsop is legendary and in December 2019 Northern Beaches Council honoured him with a park at Narrabeen called Surfrider Gardens.

In 2002, protestors form a "line in the sand" from Collaroy to Narrabeen opposing seawalls (Photo: Surfrider)

At the opening, Mayor Michael Regan spoke fondly of Tom’s achievements crediting him with “adding swathes of precious coastal habitat for protection for future generations.” The Mayor also unveiled a plaque that mentioned the “line in the sand” protest.

However, there’s an irony that could've been lifted straight out of a script for Utopia. While celebrating his record for coastal protection with a park on the Collaroy-Narrabeen stretch, Northern Beaches council was also processing a Development Application that’d threaten the very same beach. Records show the DA for the Collaroy Seawall had been lodged 18 months earlier in July 2018.

Of the people that Swellnet spoke to, the opinions of how we got to this point swung from nefarious (“It was rushed through during COVID because they knew people were occupied”) to inept (“It was signed off by a mid-level planner with no knowledge of coastal processes”). What they could all agree upon is that council has lost the trust of all who’ve opposed the seawall over the decades.

“The properties were bought in good faith,” said one local who wished to remain anonymous, “and the owners must feel an obligation for the authorities to protect them, but a seawall is last century thinking.”

In 2017, Gold Coast City Council funded, in conjunction with threatened property owners, an artificial reef offshore from Palm Beach. The theory is that the waves break further offshore, soaking up wave energy that would otherwise erode the leeshore dune system during storms. Though still in its early days, the reef - which cost $18 million - has maintained beach width since it was completed in 2019.

The idea has never been proposed for Collaroy. Instead, sand nourishment is the popular solution to maintaining beach width, though both Donohoe and Gordon are feeling ‘once bitten’ and skeptical of any council promises. 

“It would be possible to introduce a major sand nourishment program to move the shoreline seaward,” says Gordon. “The Local Government Act allows the council to set a special rate to pay for that.” Moreover, the current DA makes no mention of sand nourishment from sand sourced elsewhere, such as deeper water offshore. Instead they provide a caveat for bulldozing sand from low on the beach to higher on the beach in times of heightened storm activity - which only lowers the beach’s natural defence system.

In a story on Northern Beaches Review, Bob Orth, who lives in one of the houses behind the seawall, said the seawall should inspire others to do likewise.

"Once this is up it'll be a momentum for others to do it too," said Orth. Meanwhile, those on the other side of the divide are fearing the precedent of a return to hard structures and what this might mean for the rest of the Collaroy and Narrabeen beachfront, not to mention Wamberal, Old Bar, Byron Bay, and any other area where bad planning policy has created a wicked problem.

Comments

bonza's picture
bonza's picture
bonza Tuesday, 19 Oct 2021 at 2:15pm

Taxpayers pay millions of dollars on a asset that will require '000s thousands if not millions of dollars in annual maintenance to protect the value of a tiny handful of multi-million dollar properties owned by multi-millionaires who thought nothing of buying a property directly on a beach for a solution that only kicks the can down or up the coastline for some one one else to deal with.

seems legit.

Stephen Allen's picture
Stephen Allen's picture
Stephen Allen Tuesday, 19 Oct 2021 at 5:46pm

...and who can afford to pay the rates and any rate increases due to sea wall construction costs, which will leave rate payers on low and middle incomes moving toward rather than away from poverty.

mpeachy's picture
mpeachy's picture
mpeachy Tuesday, 19 Oct 2021 at 2:15pm

It's an interesting point whether you just blame the owners for buying a house in such a risky area and hoping taxpayers will bail them out, versus the fact that the council must have approved people building houses there in the first place (although possibly a very long time ago)

bonza's picture
bonza's picture
bonza Tuesday, 19 Oct 2021 at 2:17pm

yes i blame the owners.

mpeachy's picture
mpeachy's picture
mpeachy Tuesday, 19 Oct 2021 at 2:20pm

Found this in an old article:

"Professor Short said the council bought properties along the beachfront and turned them into parklands in the 1970s and attempted to put a moratorium on redevelopment in the 1980s, but lost its case in court."

Probably not council's fault then, happy to blame the owners!

Stephen Allen's picture
Stephen Allen's picture
Stephen Allen Tuesday, 19 Oct 2021 at 5:49pm

Now digging up the facts of this case would prove fascinating...the applicant, the judges, the arguments, the ruling etc... one if there is precedent for seeking compensation for judicial rulings made in error.

dandandan's picture
dandandan's picture
dandandan Tuesday, 19 Oct 2021 at 2:42pm

I have a blanket policy of not feeling sorry for people owning properties worth multiple millions of dollars, who have lived the better part of their lives walking from their beachfront home directly onto the sand. They've had a very very blessed life compared to anyone else in this country and that in return they would do such harm to a public place to save their private property is a bit sad.

blindboy's picture
blindboy's picture
blindboy Tuesday, 19 Oct 2021 at 3:01pm

It is all about the road. This is not a defence of the structure or the owners, just recognition that the protection of the main north south artery on the northern beaches was a factor. The NB has always excelled at extreme ugliness. Who could forget the MOLE building or the spoil from the North Head Sewage Works tipped over the cliff? Not to mention the many brutalist houses dotting its once beautiful headlands.

Pops's picture
Pops's picture
Pops Tuesday, 19 Oct 2021 at 3:06pm

I'd reckon the road, arterial services (electrical, sewerage, etc) and the houses all factors.
Painful to see such a blunt object of a solution. Would be very interested in knowing what other options were considered and why they were discarded...

lolo's picture
lolo's picture
lolo Wednesday, 20 Oct 2021 at 4:21pm

Yeah it's easy to get caught up in the house situation, but the road is at exactly the same height and built on sand too. If the houses go, the road goes shortly after. It's orders of magnitude more than a bunch of multi-million dollar properties at risk.

bonza's picture
bonza's picture
bonza Wednesday, 20 Oct 2021 at 9:56pm

Yeah nah. PW road and any associated public infrastructure was used as a eligibility factor for public funding to protect the private properties. Multiple reports have previously shown a better cost effective way to protect public infrastructure on that stretch. It’s all about the squeaky wheel.

mpeachy's picture
mpeachy's picture
mpeachy Tuesday, 19 Oct 2021 at 3:05pm

Apparently this is just one part of the seawall. More to come once the other residents agree to pay their contribution.

bonza's picture
bonza's picture
bonza Tuesday, 19 Oct 2021 at 3:13pm

The road is the public asset to be protected yes linked to their actions - but if it was really only just about PW road then surely a more cost effective way would have been to introduce less expensive and arguably more effective measures as I understand earlier reports have indicated including reveg and rock? Alas this would have meant some loss / damage to private property.
Or as the comment above lists - quoted by Prof Short - not let the property developers and real estate industry interfere with good management strategy decades ago that would have avoided council being left with a steaming pile of shit.

But it wasn't about the road - it was about appeasing multimillionaires who would have or should have known better.

blindboy's picture
blindboy's picture
blindboy Tuesday, 19 Oct 2021 at 3:28pm

I don't disagree with most of that. The question is why did the owners go for such an unattractive solution that by all appearances seems to have blocked their beach access. My guess is that their engineers took a different view of how to best manage the situation. The role of the council in all this might come out if people push hard enough.

bonza's picture
bonza's picture
bonza Tuesday, 19 Oct 2021 at 3:34pm

I think the re-sale value of their properties trumped their ability to access the from their back garden. I think they would be very happy with an ugly seawall.

gragagan's picture
gragagan's picture
gragagan Tuesday, 19 Oct 2021 at 3:42pm

If you look at the photo of the wall there appears to be a set of stairs built into the concrete for each property. So they all get their own private beach access

udo's picture
udo's picture
udo Tuesday, 19 Oct 2021 at 3:53pm

Even though they are sure to meet code...they dont look to going by the pic.

blackers's picture
blackers's picture
blackers Tuesday, 19 Oct 2021 at 5:59pm

Will be ironic if they have to pull it down for not meeting code on the steps.

Nick Bone's picture
Nick Bone's picture
Nick Bone Tuesday, 19 Oct 2021 at 6:19pm

Those first couple of staircases looked fucked. Rise seems nearly double than the run. Maybe you New South Weleshpeople do things differently. Could be the camera angle but.

udo's picture
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udo Tuesday, 19 Oct 2021 at 6:36pm

Yep need to see front on pic
Def landing size incorrect i reckon...900mm min ?

Pops's picture
Pops's picture
Pops Wednesday, 20 Oct 2021 at 9:22am

I wonder if they're intended as some kind of device to absorb/dissipate energy rather than as trafficable stairs?

memlasurf's picture
memlasurf's picture
memlasurf Wednesday, 20 Oct 2021 at 10:56am

Yes and do they have tactile indicators in the correct place? Not sure how they would fix them to the sand though.

MartinNow's picture
MartinNow's picture
MartinNow Tuesday, 19 Oct 2021 at 3:32pm

I imagine the ocean will eventually claw away under and around and over the structure. Plop!

Until then the owners can continue to enjoy their delightful seashore experience.

Its horrid!

bonza's picture
bonza's picture
bonza Tuesday, 19 Oct 2021 at 3:36pm

nothing that a annual maintenance fee paid for by the taxpayer can't fix.

blindboy's picture
blindboy's picture
blindboy Tuesday, 19 Oct 2021 at 3:39pm

Well go for them, put in your FOI requests and prove what we all suspect; that the council turned a blind eye to save themselves some money and appease a noisy minority.

bonza's picture
bonza's picture
bonza Tuesday, 19 Oct 2021 at 3:52pm

Ha! I'd imagine brendan and surfrider will have that covered. besides I’d rather just shout at my computer. and I live 8 hours away.

I’m not trying to be a dick about it. This issue is not exclusive to the NB or sea level rise or storm surge. It pisses me off that people wilfully or ignorantly choose to buy in areas that are not for purpose, enabled by the property industry and then scream out for taxpayer help when the inevitable disaster occurs. And without getting too political – it’s a good chance that the persons who own these properties will be liberal voters – so called free marketers who abhor the intervention of government in their day to day life.. except when it concerns their interests..

memlasurf's picture
memlasurf's picture
memlasurf Wednesday, 20 Oct 2021 at 10:57am

Nup it is anchored to the bedrock. Everything else may go but that wall is here to stay.

lilas's picture
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lilas Sunday, 31 Oct 2021 at 6:36am

Do you know how deep the bedrock is? Would be interesting to know the depth as it goes out to sea as well as that gives options for offshore reefs to dissipate the wave energy, therefor preventing erosion.

lomah's picture
lomah's picture
lomah Tuesday, 19 Oct 2021 at 3:55pm

that concrete is a lovely blank canvas for some choice words

waterhen's picture
waterhen's picture
waterhen Tuesday, 19 Oct 2021 at 4:07pm

First it was a track. It ran northwards around the back of the lagoon and on toward what is now Collaroy Beach. We took the easy way, down towards the ocean and along on the back of the dune. For a couple of furlongs it was quite close to the ocean but nobody cared. Structures appeared. The track became a road. We had made a big mistake that would become bigger. Much bigger. Current property values have ensured that this mistake will never be righted. I go to look at the big mistake after a big easterly storm. It looks like Chernobyl. I tear up and swear to myself. Stupid dumbfucks. Should have taken the high road.

Craig's picture
Craig's picture
Craig Tuesday, 19 Oct 2021 at 4:42pm

This isn't a new issue, as has been mentioned in the article above, and the longer we ignore the elephant in the room the harder it will become to resolve.

Surely a planned retreat is the only way forward. Just take the hit cost wise now and return the area to something close to its previous natural state. These very costly bandaids never work and continue to fail while extending the problem to adjacent properties that don't have the wall.

Google "End-wall effect erosion" and you'll find many papers/studies on this.

JD Croobyard's picture
JD Croobyard's picture
JD Croobyard Tuesday, 19 Oct 2021 at 9:11pm

Agree 100%. Unfortunately politics and money flow are not associated with longer term planning in Australia at present.

ben-colyer's picture
ben-colyer's picture
ben-colyer Tuesday, 19 Oct 2021 at 4:53pm

What a clusterfuck.

Westofthelake's picture
Westofthelake's picture
Westofthelake Tuesday, 19 Oct 2021 at 5:11pm

Wow that is #sododgy.

crg's picture
crg's picture
crg Tuesday, 19 Oct 2021 at 5:21pm

Perfect canvas for Banksy

Thegrowingtrend.com's picture
Thegrowingtrend.com's picture
Thegrowingtrend.com Tuesday, 19 Oct 2021 at 5:24pm

Northern Beaches Council are the biggest tossers ever. They have destroyed every built form on the beaches. Turned this place into a concreters paradise

blindboy's picture
blindboy's picture
blindboy Tuesday, 19 Oct 2021 at 5:41pm

There are plenty of other spots along the coast vulnerable to rising seas and more intense storms but Collaroy is one of the most difficult to address. And as I said in my first comment that is because of the road. There is a significant risk that, as Craig suggested, end wall erosion will simply move the problem and lead to calls for extending the wall. If that is to be avoided there needs to be a concerted effort to gain the support of the wider NB community to create pressure on the council to develop a more acceptable plan.

memlasurf's picture
memlasurf's picture
memlasurf Wednesday, 20 Oct 2021 at 11:04am

BB who is getting the sand which has gone from here? On the MP they blew the heads up and the erosion from Portsea front beach to the heads is crazy. Big walls like this one are getting smashed and although for the most part they are still there, everything behind them is going. All the sand has moved south east where previously there were great rock lagoons there is now 100 metres of sand dunes. Old bathing boxes which were on long piers sitting out in the bay are now sitting in the middle of sand dunes. Lindsay Fox is happy as a vegemite as he now has what he wanted all along, more real estate to land his helicopter on.

willibutler's picture
willibutler's picture
willibutler Tuesday, 19 Oct 2021 at 5:46pm

Hey guys I need to write an informative paper based on remedial measures used to protect infrastructure against erosion. Link any useful papers you’ve found. I’ve already done some research but the swellnet knowledge base is one of the best in this area

zenagain's picture
zenagain's picture
zenagain Tuesday, 19 Oct 2021 at 5:50pm

If you want to witness how to do irreparable damage to a coastline, look no further than Japan. As the article states, in terms of erosion, vertical walls don't work and actually exacerbate the problem. I hope this Collaroy wall hasn't set a precedent.

btw- that one is a tiddler compared to what they have here.

zenagain's picture
zenagain's picture
zenagain Tuesday, 19 Oct 2021 at 5:56pm

https://arstechnica.com/science/2016/11/covering-coasts-with-concrete-ja...

Here Willi. Check this out. Japan may be a perfect case study.

willibutler's picture
willibutler's picture
willibutler Tuesday, 19 Oct 2021 at 6:08pm

Thanks so much zen! I watched a 4 corners or foreign correspondent thing last year on the Japan sea walls. So fkd how big some of those sea walls are and just ruin the towns completely and those that rely on the area

gsco's picture
gsco's picture
gsco Tuesday, 19 Oct 2021 at 6:39pm

They’ve done the same thing to much of Taiwan’s coast, see eg: http://www.irjes.com/Papers/vol6-issue10/F61012431.pdf

zenagain's picture
zenagain's picture
zenagain Tuesday, 19 Oct 2021 at 6:49pm

Yep, basically pork-barrelling on a massive scale and the Japanese sold them the lie too.

udo's picture
udo's picture
udo Tuesday, 19 Oct 2021 at 6:06pm

.

stunet's picture
stunet's picture
stunet Tuesday, 19 Oct 2021 at 6:24pm
zenagain's picture
zenagain's picture
zenagain Tuesday, 19 Oct 2021 at 6:59pm

Thanks Stu, didn't even know such a thing existed here.

What they fail to mention is the massive corruption that's involved in awarding these contracts and the fact that the construction companies themselves for the most part, are predominantly Yakuza.

velocityjohnno's picture
velocityjohnno's picture
velocityjohnno Wednesday, 20 Oct 2021 at 9:24pm

That's crazy stuff. The Collaroy wall is not subtle.

Balbero's picture
Balbero's picture
Balbero Tuesday, 19 Oct 2021 at 6:57pm

" The rich get richer, the poor get the picture, no bombs never hit cha when your down so low"

Hazrus's picture
Hazrus's picture
Hazrus Tuesday, 19 Oct 2021 at 8:05pm

I've got a mate who works for MHL as a coastal engineer. I will check with him and report back.

tango's picture
tango's picture
tango Wednesday, 20 Oct 2021 at 9:46pm

That's the most sensible thing I've read so far.

BD's picture
BD's picture
BD Tuesday, 19 Oct 2021 at 9:07pm

It’s an issue the whole coastline, councils desperate to get what is a liability off their books and some homeowners, beachfront, genuinely caught out by it. Not every beachfront owner is a cashed up prick, some have been there 50 years when climate change etc wasn’t on the radar. Sure if you’ve bought the last 5 years ignorance can’t be an excuse, but there’s nothing wrong with wanting to live on the beach. Staged retreats seem the best option, but also some councils are genuinely desperate to embrace the most apocalyptic climate change forecasts. Super difficult problem, maybe councils could buy beachfronts then lease back the properties. But obviously no owners want to give up tax free capital gains.. dunno has to be a solution that doesn’t destroy the beach like collaroy or completely crush home owners, they aren’t all pricks

bonza's picture
bonza's picture
bonza Tuesday, 19 Oct 2021 at 9:59pm

Hey BD. property owners in Collaroy have seen the value of their asset increase by around 20-30% in the last 12 months alone. More than double in wealth the last 7 years. They aint getting crushed. They are multi millionaire asset owners.

If the council are desperate to get a liability off their books then they have totally screwed it. They have just invested in an asset that requires 60 years of maintenance. Furthermore they have facilitated an increase of erosion to adjacent beaches. By doing so they have encouraged similar management intervention from beachside landholders by 1. demonstrating part liability for coastal erosion processes by building such a structure that threaten adjacent properties and 2. Seeing and continuing a precedent that the government should pay and protect small groups of private landholders while the property owner reap the benefit and profit of rocket fuel property prices.

as the article states coastal erosion has been known since the 20’s in that area and has been studied meticulously ever since. there is no excuse for purchasing a property on the beach in the last 30 years let alone 5 without an inkling of understanding of the risks.

It would have been a bargain 20-30 years ago to buy the properties and return the space to the public for the purpose of more effective less intrusive, natural and cheaper remediation efforts. It will still be a bargain now compared to 60 years from now if they do the same.

why should the taxpayer pay to protect a small number of private landholders who actively choose to profit from purchasing in a tidal zone?

It is a difficult and wicked problem. as my old mate hutch likes to say. the hardest decisions should be the easiest.

BD's picture
BD's picture
BD Tuesday, 19 Oct 2021 at 10:24pm

Sorry wasn’t specifically referring to collaroy which I completely agree has been a known and long term problem. Where I live though the beach has no erosion issues but the council is trying curtail landowners rights significantly due to potential sea level rises combined with 1 in 100 year storms etc. they might be right basis forecasts but beachfront owners bought in an area that didn’t previously exhibit high erosion issues. I’m just saying it’s a difficult issue, beachwall terrible and if it’s sets a precedent huge chunks of the coast stuffed.

Mistyblue's picture
Mistyblue's picture
Mistyblue Wednesday, 20 Oct 2021 at 8:48am

Completely agree that not all beach owners are cashed up pricks. However, a few queries regarding your post: "Sure if you’ve bought the last 5 years ignorance can’t be an excuse" - why does five years give one grace? There have been high profile storms on the NSW East Coast since the mid-70s. Also, "some councils are genuinely desperate to embrace the most apocalyptic climate change forecasts" - in your view what are "apocalyptic forecasts" of climate change and which councils are you referring to? Sea level rise equation is based on the Bruun Rule to ascertain erosion in open coastal areas like Collaroy.

BD's picture
BD's picture
BD Wednesday, 20 Oct 2021 at 9:51am

Hey there - well I live in Noosa, Sunshine Beach specifically. I looked at the Bruun rule - i think it was roughly 10cm sea level rise = 1metre of beach vanishes? did depend a lot on steepness of the beach etc. I find the whole thing fascinating, I had guys from the council to my face tell me of a future with 52 day heatwaves & in the same breath tell me of being concerened about extreme cyclones & erosion. Cyclonic activity isnt forecast to increase at all - I think the jury actually out on that at the moment, east coast of Australia in a 500 year dip too on cyclonic activity. I think we have already seen 19 cm of sea level rise on the east coast - and at least up here it hasnt translated to any significant/extended erosion issues. All the reaserch I did seemed to show that the headland affect and beaches just north of those headlands, i.e. collaroy vs long reef, have always had signifcant erosion issues. With expected sea level rises obviosly making those matters worse - however there is some irony in the fact Gina Reinheart whose carbon footprint is horrendous, just bought the most exposed land in sunshine beach to these very issues - but im also stressed people like her etc will want to build sea walls down the track. the council up here is anti sea walls, but there is a thread that runs through them very much of "stuff the beachfront guys - they are rich". The point i guess im coming to is, and i know an old couple whose property is very exposed to this issue, who have lived there since 1960's and are now in their 80's and likley won't see the impeding issues in their lifetime - but really they have done nothing wrong, bought an old shack in a place they love when no one lived up here, I wouldnt say there are a lot of people left like that but there are a few I know up here a version of that and the whole "screw those rich pricks" mantra is just divisive. Much better to work out a solution where the public doesnt lose their beach as per collaroy, but councils/government do need to help landowners. I am actually shocked the collaroy houses in particular have gone up in value - i wouldnt be able to sleep at night living there!

willibutler's picture
willibutler's picture
willibutler Tuesday, 19 Oct 2021 at 9:28pm

other than just the width of beaches increasing, has anyone actually seen a full dune rebuilt. This process must require wind over thousands of years but people and waves stomping over dunes seems like any dune system near a popular town once destroyed wont come back?

willibutler's picture
willibutler's picture
willibutler Tuesday, 19 Oct 2021 at 10:25pm

C7-DFBE63-30-EB-4348-9-B83-FB7-E99405-C88
C54-E2-F13-45-F3-44-A7-9-B51-739-B9-D2350-E6

willibutler's picture
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willibutler Tuesday, 19 Oct 2021 at 10:29pm

Most of these dunes have been heavily impacted by the La Niña easterlies over the last 2 years causing several car parks next to the beaches to be roped off. On top of this living around moruya last year the slow gently shaped dune leading into the beach was transformed for a straight 3m high drop off that you had to jump down by the end of all the ECL”s around August. Would be interesting to see the state of that beach on the north side of breakwall now

willibutler's picture
willibutler's picture
willibutler Tuesday, 19 Oct 2021 at 10:32pm

This was the same dune system a few years before all these easterlies
0706091-A-15-BE-4527-BC5-C-9128-CB6530-D7

willibutler's picture
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willibutler Tuesday, 19 Oct 2021 at 9:42pm

As parts of the great ocean rd have began to crumble into the ocean. They’ve introduced these gently sloped walls to broaden the widths of the roads to protect them from erosion. Luckily these sections of the Roads are at the far inside of pointbreaks so the wave energy is mostly weak, with little rebound affect. Although ill be constantly monitoring the situation and around at cathedral the beach profile has certainly been getting steeper. I’m worried they will put one of these in at a beachie around here as the carpark and rd are imminent to be taken by the ocean and I’m sure that will dramatically change the profile of that beach.

This is an example of the walls they’ve been placing. They blend in quite nicely and have provided easier access to the breaks and so far been a success in the regions they’ve put them so I fear they’ll continue to put them in everywhere thinking they won’t caus too much damage to beach profiles elsewhere. Mind you they’ve only been around for a year. 67-DAD7-EF-C3-EA-4280-A4-D6-ED3-CD3-A22-ADB

willibutler's picture
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willibutler Tuesday, 19 Oct 2021 at 10:24pm

827412-E9-9758-4-C06-941-F-666-E49-EF9-E64

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willibutler Tuesday, 19 Oct 2021 at 10:37pm

This just a year ago was a nice Sandune. Will be interesting after another summer if potential strong easterlies due to the La Niña. How many parts of the great ocean rd could have to close and the emergency that would lead to.
274-A8-FAD-EED7-4796-B9-FF-EA6-F300-F68-C9

willibutler's picture
willibutler's picture
willibutler Tuesday, 19 Oct 2021 at 10:45pm

They are trying to protect a life saving club, which footings lie directly on the sandunes that eroded due to not only the waves but also the changing in direction and position of the mouth of the river (natural process). This has cut into the base of the dunes below the surf club. They have just completed digging out a new path for the river to follow with excavators and every day I’d watch the next morning after high tide their progress would seem effortless and the river would tend to follow the old direction. On top of this they have places sand band grounds out perpendicular to the sandunes.
F1-A4842-A-5-B11-4-A39-869-C-C1-F650-AB24-FC
EBCDC68-A-566-F-4119-9179-9-C5-BF6539151
0-A96211-B-D510-429-C-BF07-4-A0-C77-E31-DA9
B1-E40-B5-A-26-A3-4-C50-9306-83-A237-F0-ABC8

velocityjohnno's picture
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velocityjohnno Wednesday, 20 Oct 2021 at 9:33pm

good pics there willi, hadn't realised this. It's eroded locally at present, lots of rocks revealed on low tide but it's also end of winter.

baysurfer's picture
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baysurfer Thursday, 21 Oct 2021 at 1:57pm

check out the beach erosion in Apollo bay as well
governments recently built a bunch of groynes around the Murray street area

Distracted's picture
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Distracted Tuesday, 19 Oct 2021 at 10:51pm

Willi, how would easterlies impact the Great Ocean Road coast? I wouldn’t have thought there would be much fetch?

willibutler's picture
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willibutler Tuesday, 19 Oct 2021 at 11:37pm

There isn’t much fetch so it’s only ever weak 1-4ft tops of onshore wave after wave onslaught, this a particular problem at high tide caus most bays and points usually go flat at high tide but under an easterly scenario the easterly windswell pushes right up to the dunes, and easterly swells require lots of wind and from what I’ve read on swellnet these large storms if the pressure is low enough will raise sea levels higher than normal.

Normally large swells from the SW have very little affect on the beaches around here because the great ocean rd is comprised of Rocky headland after headland. Most swells will have to wrap around the rock/reef headlands as well as cape Otway before this and nicely wrap the swell into the bays and our coast has been shaped like this for however thousands of years so it is used to it, and this is what us humans observe as the “normal” state of the beaches as they are quite predictable and don’t change much around here.

However the short period easterly swells go straight into all parts of the surfcoast digging it up and turn almost every beach with low swell energy into an ugly mess. Just look at the surfcams tommorow morning, will be another case of ugly easterly that will make problems worse.

Btw when I say 4ft these waves 99.99% of the time are sloppy, they break for half a second and then dissapear and it’s an ugly wash for kms out to sea

tango's picture
tango's picture
tango Wednesday, 20 Oct 2021 at 9:57pm

The GOR situation is far more complicated than Willi's well-intentioned advice makes out. The coastline in SW Vic has evolved to respond to a dominant SW swell and storm pattern - that's why the beaches face the way they do. Any system that affects the coast from a different angle upsets the balance of that orientation and the system then takes considerably more time to re-adjust. There's been significant coastal erosion (acute) along the GOR in recent years, though only a handful of places have experienced coastal recession (chronic). But several of those areas experiencing recession are linked to important infrastructure that the authorities want to protect - depending on were you are, the GOR also houses telecoms, sewerage and other infrastructure. At this point, the relocation business case doesn't seem to stack up.

willibutler's picture
willibutler's picture
willibutler Wednesday, 20 Oct 2021 at 10:48pm

Yea I agree with this. Took the words out of my mouth

lilas's picture
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lilas Wednesday, 20 Oct 2021 at 6:27am

Can somebody please sack almost ALL so called coastal engineers for Fuck's sake!

Better still put them on a rocket for deep-space explorations [the missions that don't return]
I just can't see HOW these monstrosities ever get approved, purely on an engineering level.
What sort of idiots approved this shit? They are the real villains, as regardless of what anyone says or does, these idiots can allow or disallow engineering developments so the buck stops there!

gragagan's picture
gragagan's picture
gragagan Wednesday, 20 Oct 2021 at 10:07am

Bullshit. The engineers would have likely argued against this for the reasons given above (and then some). There's no sense at all in building something like this from an engineering perspective. Ignorant clown

lilas's picture
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lilas Thursday, 21 Oct 2021 at 6:22am

"There's no sense at all in building something like this from an engineering perspective. Ignorant clown"
You may call me names, but the facts still stand.
An "Engineer/s" designed this monstrosity and other "Engineers" approved it. You can cry about why it wasn't their fault but that doesn't change anything at all. If they were 100% against it but felt they had no choice but to design/sign it, then they simply have no morals/ethics/backbone.
Nothing can ever excuse extremely poor and ill-conceived designs. You wouldn't accept that in a bridge from an engineer, so why accept it in anything else?

theblacksheep's picture
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theblacksheep Wednesday, 20 Oct 2021 at 6:29am

Looks perfect for high tide backwash to spread up and down the beach

The best defence is a good offence

lozv's picture
lozv's picture
lozv Wednesday, 20 Oct 2021 at 6:50am

OMG!!!!....Basic, crude, primitive, a fcukn disgrace and no regard for the beauty of the area...just shit!....Year 7 school project standard.

Owners, Council and 'engineers...shame shame shame

Optimist's picture
Optimist's picture
Optimist Wednesday, 20 Oct 2021 at 7:46am

They may have a wall, but there will be no beach in front of it.

No mal half a quiver's picture
No mal half a quiver's picture
No mal half a quiver Wednesday, 20 Oct 2021 at 8:15am

Take the houses away eventually they would be building a wall to protect that road that you whinging moles drive around on for 20min checking it. Or boarding a jumbo jet to go for a surf and buy the latest board all things responsible for the needing of the wall in the first place.
Only thing that would be better if they made a foot path on top of it so wheel chair bandits and a like get to use the cost line as well

stunet's picture
stunet's picture
stunet Wednesday, 20 Oct 2021 at 8:17am

"Or boarding a jumbo jet to go for a surf and buy the latest board all things responsible for the needing of the wall in the first place."

Wot?

EDIT: Just to be clear, the issue of erosion has nothing to do with sea level rise, climate change, or buying the latest board. The root cause is building on the foredune. In the future, the problems may well be exacerbated by the above but they did not cause it "in the first place".

san Guine's picture
san Guine's picture
san Guine Wednesday, 20 Oct 2021 at 8:37am

Wow, that is ugly even by brutalist/modernist standards. Ratepayer/taxpayer bailout, so business as usual... whatever happened to caveat emptor?

Mistyblue's picture
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Mistyblue Wednesday, 20 Oct 2021 at 8:52am

Some interesting papers about building seawalls and the effect it has on risk perception in the post Tsunami context in Japan:

Littlejohn (2020) "Dividing worlds tsunamis, seawalls, and ontological politics in Northeast Japan"
Kimura (2016) "When a seawall is visible: Infrastructure and obstruction in post-tsunami reconstruction in Japan"
Yamashita (2020) "Living together with seawalls: Risks and reflexive modernization in Japan"

Hall of Lame's picture
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Hall of Lame Wednesday, 20 Oct 2021 at 9:14am

Just wondering if the stairs built into the wall are private property?

blindboy's picture
blindboy's picture
blindboy Wednesday, 20 Oct 2021 at 10:57am

Looking at that DA via Stu's link, it must have taken a considerable, possibly illegal, effort to keep that out of the hands of those community members with a long record of interest in the matter. Might be time to lawyer up.

Iced vovo's picture
Iced vovo's picture
Iced vovo Wednesday, 20 Oct 2021 at 6:59pm

There is currently an online petition to stop it extending to the Marquees. I no longer live in the area but just can't believe it has progressed so far without anyone noticing.

dinnerdish's picture
dinnerdish's picture
dinnerdish Wednesday, 20 Oct 2021 at 8:10pm

I wonder whats worse this concrete monstrsity or the digital identity certifcate which is about to be become a reality unless you put some energy into being another voice presenting a social inclusivity rather than “If there is an identity card, then people in authority will want to put it to use….What is at stake is nothing less than the nature of our society and the power and authority of the state over the individual”

tango's picture
tango's picture
tango Wednesday, 20 Oct 2021 at 10:05pm

I can't believe that those structures have been built in 2021 and that the legislation still hasn't been amended to counter the property rights of the owners. Its like something out of a dystopian movie.

It's good to see some enlightened input from Brendan and Angus, both of whom have extensive experience in coastal management from planning and engineering backgrounds. However, NSW has an intricate coastal management and development approval system and surely there's a paper trail for the various consents and approvals for this abomination which would be subject to FOI? Given that it seems to fly in the face of best practice, has anyone asked what the NSW Coastal Council has to say about it?

Such a shame that it's not like California or other US states where the owner has no right to protect their land from erosion etc.

This sets a very dangerous precedent for the rest of NSW.

DBEARINDARE's picture
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DBEARINDARE Wednesday, 20 Oct 2021 at 10:27pm

Can't wait to see the classic "Dick and Balls" painted on that big ugly fucker.

Fliplid's picture
Fliplid's picture
Fliplid Thursday, 21 Oct 2021 at 7:20am

Time to get Brian on the job

Crab Nebula's picture
Crab Nebula's picture
Crab Nebula Saturday, 23 Oct 2021 at 9:35am

Inevitable as the ocean winning, is a painted "cock and balls" on that wall.

blindboy's picture
blindboy's picture
blindboy Thursday, 21 Oct 2021 at 12:32pm

Here is the DA for the wall. I am looking at it but there is probably someone better qualified out there.
https://eservices.northernbeaches.nsw.gov.au/ePlanning/live/Public/XC.Tr...

blindboy's picture
blindboy's picture
blindboy Thursday, 21 Oct 2021 at 12:46pm

First red light!
42 online submissions ALL supporting the wall but many seem to think it would be a sloping rock construction. And ALL received in a 3 day period 17-19 July 2017

I think I will dig a bit deeper!

So there is probably another DA somewhere.

blindboy's picture
blindboy's picture
blindboy Thursday, 21 Oct 2021 at 12:54pm

OK this is the real one.
https://eservices.northernbeaches.nsw.gov.au/ePlanning/live/Public/XC.Tr...

10 online submissions. 8 for 2 against

blindboy's picture
blindboy's picture
blindboy Thursday, 21 Oct 2021 at 1:00pm

And this (Item 4) gives the reasons they changed to a wall

https://eservices.northernbeaches.nsw.gov.au/ePlanning/live/Common/Outpu...

bonza's picture
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bonza Thursday, 21 Oct 2021 at 1:20pm

Thanks BB.
Section 2.4 Item 4 - classic stuff

blindboy's picture
blindboy's picture
blindboy Thursday, 21 Oct 2021 at 1:27pm

Compare their prediction of how it would look with the reality shown above..

Screen-Shot-2021-10-21-at-1-13-46-pm

willibutler's picture
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willibutler Thursday, 21 Oct 2021 at 2:39pm

https://www.eventbrite.com.au/e/climate-change-and-coastal-erosion-the-g...

GOR coastal erosion webinar link for today at 3pm for those interested

bigtreeman's picture
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bigtreeman Thursday, 21 Oct 2021 at 5:12pm

The only place for a residence next to Narrabeen Beach was up on the headland. Bumper Farrell had the prime position.

Crab Nebula's picture
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Crab Nebula Saturday, 23 Oct 2021 at 9:06am

Though not failsafe in extreme events, isnt it amazing how reefs and well-place gabions somehow protect small atolls in middle of the ocean for most of the time? Whether concrete castles or sand castles, buildings that close to a sand shoreline must be living on borrowed time. They must only exist on a dense (and expensive) schedule of maintenance, no doubt. At what point are they a write-off? This wicked problem is a result of intergenerational dumbness. A barrier reef in place would no doubt have knock-on effects. I mean, did someone forget about the old idiom about 'shifting sands' or what? Futile.

truebluebasher's picture
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truebluebasher Saturday, 23 Oct 2021 at 10:28am

It is possible that this is part of the Silverback's Seachange pork barrel rollout.
Ocean Pools > Skate Bowls > Wave Pools > "Boomer'z Backwash Booger Bowl"

Crew requested the Turning Japanese Tool Box

History of Collaroy Erosion / Wave Pools / Tow Surfers

2016 Collaroy seawall Concept Design Specs
https://files.northernbeaches.nsw.gov.au/sites/default/files/collaroy-na...

Collaroy Stormwater Pipe Outlet
https://nationalprecast.com.au/wp-content/uploads/2015/06/Collaroy-Beach...

2020 Surfer keelhauled by Collaroy Stormwater Pipe {RIP}
https://www.9news.com.au/national/weather-nsw-sydney-collaroy-surfer-pul...

Sydney 'Living' Seawalls
https://lighthouse.mq.edu.au/article/september-2021/Living-Seawalls-in-g...

5 min [P] Call of the Wild skinny dip at yer local Sea-Wall...just doing wot comes natural! (AO)
https://www.odt.co.nz/news/dunedin/tarzans-stormy-st-clair-skinny-dip

Last Wave in...always team up with surf buddies to safely exit yer local Seachange Monstrosity.
https://static01.nyt.com/images/2017/01/28/world/28israel6/28israel6-sup...

Sea-change hostage negotiations at Hellhole of the Pacific...
Kook survives a brutal seawall bashin' ...well almost!
As hostile native rescue party moves in for the kill...Oh the Humanity...reads Humility...reads Kook!

PAG's picture
PAG's picture
PAG Sunday, 24 Oct 2021 at 12:48pm

Im presuming that sand delivery's from the lagoon will be an ongoing thing. I also presume the view of the houses will be enhanced by the no trespassing signs in large red writing. Perfect future film location for backwash kook of the day.

mpeachy's picture
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mpeachy Monday, 25 Oct 2021 at 4:23pm

Would suck if you got amalgamated into Northern Beaches council then had to pay tax for this

bonza's picture
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bonza Monday, 25 Oct 2021 at 4:57pm

we all end up paying for it directly if we haven't already e.g. consultant reports and community consultation no doubt funded by state money. LGA's apply for state and federal funding on offer for range of purposes. The obvious one is disaster relief which will be a given in the medium to long term for the repair of the wall and its impacts to adjacent beaches. These are the taxpayer funded grants that LGAs will apply for, to repair the wall. But there will also be a range of other social and environmental grants on offer that the LGA will use to leverage off for on-going maintenance. they will use loop holes to ensure eligibility. buzzwords include "Improved recreational access. " increases social amenity". "community engagement", and my personal favourite "building resilience".

lance.knight's picture
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lance.knight Tuesday, 26 Oct 2021 at 7:37am

In 1974I witnessed what cyclonic ocean power can do to ignorantly planned beach development 50 years on and a lot of sea miles under my belt. I am thinking that sad as it may be, we will never be able to turn back the clock and have a natural passive coastline of Sandhills and trees. Greed and stupidity rule in councils . The only way now is to harness the power of coastal construction science and engineering. Lets do the modelling and begin building offshore wave traps and manmade surf-breaks. We have the tools and imagination to manage the climatic challenge that beginning to show in my lifetime. Lets bring it on. Surf Breaks Inc. Coming to a beach near you ! Lance Knight

lilas's picture
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lilas Monday, 1 Nov 2021 at 7:28am

"We have the Tools and imagination"
We do, but unfortunately we also have a pervasive mindset in surfing that everything should stay the same as it was back in the good old days. Those days are gone, but we can make the future even better IF we use our brains like you say!

udo's picture
udo's picture
udo Tuesday, 26 Oct 2021 at 7:51am

Lance any surf info about Middleton Reef ?
Maybe start a thread in the Forums...and you must have a few Wild sea tales to tell with 560 Lord Howe trips under your belt.

thermalben's picture
thermalben's picture
thermalben Sunday, 31 Oct 2021 at 6:45am

I'm not entirely sure, but one of the reasons why an offshore reef structure hasn't been considered for Narrabeen may be because it's part of the Northern Sydney Protection Zone, hosting submarine cables that connect Australia to various parts of the Pacific (including Japan).

Amongst other things, it is illegal to "establish, maintain or use a spoil ground or other ocean disposal point (including dumping materials at sea)".

https://www.acma.gov.au/zone-protect-sydney-submarine-cables

lilas's picture
lilas's picture
lilas Sunday, 31 Oct 2021 at 7:07am

That makes sense Ben. What a pity as the potential for offshore reefs around there is really good.
I guess that makes offshore options quite limited

lilas's picture
lilas's picture
lilas Sunday, 31 Oct 2021 at 7:03am

So I'm a little confused as to why there are hardly any real solutions put forward to deal with coastal erosion in 2021, despite our huge body of scientific knowledge regarding the issue

In the end it's all pretty simple though, as most beach erosion of consequence is caused by large/powerful waves. Large waves have a lot of energy and must be forced to break further out to sea to dissipate the energy before reaching the sand shoreline.
This can easily be achieved by creating offshore reefs that reduce the energy to a level the beach can cope with. [Just like in Hawaii]
By creating offshore reefs that only interact with the largest [damaging] swell events, the normal beach processes can be maintained by allowing small to medium swells to pass unaffected and continue the normal flow of sand.
Offshore reefs would be expensive , but we are already spending 100's of millions on bad solutions that actually cause more problems than they solve so money cannot be used as an excuse.

As mentioned in an earlier post, I place the blame fair and square at coastal engineers who design and approve these ill-fated designs. No more excuses for your terrible workmanship anymore.
If you don't know know shit about the processes of the ocean and coastal erosion then please put your hand up and say so. Building a vertical [with over-top] wall is about as insane a design as you can get, as stated and proven by all the intelligent people on this forum.
You would never be allowed to build an incorrectly designed bridge, so why do these people get away with doing that at our beaches ?

tonys-shirtfront's picture
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tonys-shirtfront Sunday, 31 Oct 2021 at 10:07am

Stick your comments up your arse fuckwit engineers dont approve shit like this they get paid to do what they are told direct your retarded comments at millionaire house owners and council you piece of shit

lilas's picture
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lilas Monday, 1 Nov 2021 at 7:21am

Take a chill-pill mate, or possibly the whole packet as it appears you need them.
The politicians and land owners actions are an entirely separate discussion and I'm not entering into that minefield! Plenty others have discussed it.
The fact that an engineer/s designed this crazy-ass wall is the concern I raised.
So would you like to inform me as to WHO designed this monstrosity if it wasn't an Engineer?
Was it some random guy off the street?
You said "They get paid to do what they are told to do" Were they told told to design a system that would not work for the purpose and only exacerbate the problem? Highly unlikely!
The facts stand as such, an Engineer/s designed this monstrosity and no amount of excuses can change that. And please take a look at all the other ridicules things Coastal engineers are doing around this country so you can see the pattern of incompetence I am referring to. There is a common denominator here, "Coastal" engineers with a lack of knowledge and understanding of coastal processes.

tonys-shirtfront's picture
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tonys-shirtfront Sunday, 31 Oct 2021 at 10:09am
blindboy's picture
blindboy's picture
blindboy Sunday, 31 Oct 2021 at 10:52am

I think the wall is actually a good warning of exactly what governments mean by "adaptation and mitigation".....expensive projects for the construction industry rather than sound ecological management.

gragagan's picture
gragagan's picture
gragagan Sunday, 31 Oct 2021 at 1:28pm

It would be a good idea to put in a surf cam in that pans up and down the wall to document any changes to the beach, sand movements, erosion problems etc. Could be some good entertainment next time some serious swell hits.
And it would also provide some useful evidence for fighting against any similar future proposals.

udo's picture
udo's picture
udo Sunday, 31 Oct 2021 at 2:03pm

blindboy's picture
blindboy's picture
blindboy Sunday, 31 Oct 2021 at 2:02pm

I have written to the Office Of Local Government about my concerns over the hiding of the second DA. Their email is: [email protected]

blindboy's picture
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blindboy Monday, 1 Nov 2021 at 1:45pm

I put up links to both DAs the other day. Whe I checked the link today on the second one it went to the first DA for the sloping rock wall, not the second one for the vertical concrete wall. I am pretty sure the link was correct when I posted it. If anyone used it and saw the second DA let me know. The second DA is now here. Click on "Documents" for the interesting stuff.

https://eservices.northernbeaches.nsw.gov.au/ePlanning/live/Public/XC.Tr...

lilas's picture
lilas's picture
lilas Tuesday, 2 Nov 2021 at 2:43pm

I wrote to Many Hydraulics Laboratory to ask for the details regarding the sea wall assessment they produced.
In the Doc below, They advised to do more Numerical modeling [Physics simulations] to be sure of the walls effect. Not sure if that happened though. Will try and find out.
Also, ALL the Numerical modeling was done in comparison to the current altered beach-state and NOT to a natural beach-state so there is bias in modeling things that way even though the beach state is not natural any more.
https://files.northernbeaches.nsw.gov.au/sites/default/files/documents/g...

blindboy's picture
blindboy's picture
blindboy Tuesday, 2 Nov 2021 at 3:37pm

Thanks lilas. I think this was done for the first DA, the sloping rock wall, rather than the vertical one that was actually built. If that was the only report they did then it would be good to know on what scientific advice, if any, they changed the plan. I am working on a gipa application to try and find out what community consultation they did for the second DA. It is worth remembering that this council, as Warringah, council, was twice dismissed for corruption and incompetence. My working assumption is that they have behaved unethically on this matter. It might take a bit of digging to prove it, but the evidence is accumulating already.

Craig's picture
Craig's picture
Craig Tuesday, 2 Nov 2021 at 3:46pm

RÜFÜS DU SOL's new album cover to Surrender is on point..

udo's picture
udo's picture
udo Tuesday, 2 Nov 2021 at 4:04pm

Collaroy sea wall ...1.8 mts higher than the Berlin Wall...

dave's picture
dave's picture
dave Friday, 12 Nov 2021 at 12:20am

https://i.imgur.com/DuHM6zJ.gifv
The above video might be of interest to help understand the design of the wall. It shows how different combinations of coastal defences and wave and tide conditions affect overtopping and flood risk

Craig's picture
Craig's picture
Craig Friday, 12 Nov 2021 at 7:07am

Sure, but wowee regarding that huge backwash and wave entering back into the surf zone. Can't see sand staying around with all that crazy activity. And the properties either side?? Surely going to get all crazy reverb and backwash stripping their sand more rapidly as well.

That 3-4x the height of the curved revetment? Ray Collins eat your heart out..

thermalben's picture
thermalben's picture
thermalben Friday, 12 Nov 2021 at 7:21am

Good find. Here's the full video with audio.

Craig's picture
Craig's picture
Craig Sunday, 5 Dec 2021 at 1:42pm

Surprise surprise!

And this is on a small, weak windswell from the south-east.