Coastal erosion thread

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velocityjohnno started the topic in Saturday, 15 Jun 2019 at 10:47am

There's not really a coastal erosion thread that I can see, beyond some excellent articles on the site. Post up examples you find in your area, and maybe how the sand banks and wave quality change.

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velocityjohnno Saturday, 9 Nov 2019 at 11:27am

LD - probably did handle them briefly, within the context of lab work. And was also on site, but I won'd disclose which/where, respecting the clients. I'd assume it would be similar across many operations like this world-wide, and that some sands (as well as granite, for example) possess a slight radioactivity. The doing bit was my job - I loved that line of work, all the travel, new sites, new people, remote work.
And yes, you get to see things occasionally that make you go "Whoa!" Exposure to many substances will have safe "limits" usually imposed after much study, and I'm happy I was within those limits. Er, hopefully...

What I'd like to say is: "The radioactive sands... changed me and gave me super-powers. I can now look through clothing pieces. I now act tirelessly for the greater good, only choosing when to use my powers with great restraint." As Leslie Nielsen said: "With great power, comes..."

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Lanky Dean Saturday, 9 Nov 2019 at 4:03pm

Great responsibility!

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velocityjohnno Sunday, 10 Nov 2019 at 2:29pm

Absolutely!
Original clip:


And a bonus, pretty dangerous in coastal dune systems:

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morg Tuesday, 12 Nov 2019 at 1:04pm

At a more localised level around Newcastle, a few of us have a theory that in addition to the sand dune stabilisation (e.g. Nobbys) and shore stabilisation along Merewether/Bar Beach stretch, the restricted stormwater outflow onto the beaches has also adversely impacted the sand banks and waves. For example back in the day there were pretty consistent left and rights directly off the drain outflows at Merewether, South Bar, Southey, and Newcastle. Just a theory, but appears to be more than coincidental. As a side note the the restricted freshwater outflow has also contributed to the lower level of oysters around the rocks these days (change in salinity for spawning).

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mowgli Wednesday, 23 Sep 2020 at 5:12pm

One thing to be mindful of when comparing the beach condition you see now with what you knew it to be decades ago....what you're seeing now could very well be the "natural" (i.e. closer to the long term/steady beach state) and what you recall as being all-time in your younger years may have been in a post-storm/early recovery phase.

As for groyne suddenly turning on ya...same rule applies, it can take 30 years for the consequences of a specific change to fully play out.

The reasons for these vary greatly.

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Distracted Wednesday, 27 Nov 2019 at 9:41pm

VJ, any thoughts on use of tank traps as a coastal erosion measure plus anti-SUP device ;-) as opposed to the relatively harmless marram grass!

On a serious note does pretty sound dangerous and it is also interesting that they are being exposed as at some point that must have been the natural beach profile.

https://au.news.yahoo.com/potentially-fatal-hazard-exposed-on-popular-be...

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mowgli Tuesday, 3 Dec 2019 at 1:32pm
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velocityjohnno Tuesday, 3 Dec 2019 at 6:41pm

Just saw your tank-trap post Distracted, I admit I had to look the term up. As suspected, they are barricades to stop tanks! One thing that's interesting is that they were buried and are re-exposed, which suggests the coastline profile was more receded in the 1940s? Maybe something happened after then to build up sand over the traps?
Around here, we have these wooden barriers extending out into the sea at the TQ front beach. When the sand is taken away (like now, with all the Sudden-Stratospheric-Warming related Westerlies and large out-of-season swells associated) they become an obstacle for logs/SUPs/groms at one of the fav grommie spots. Not too nice to ride into one at high tide!
I always thought that if someone could design an ocean version of a snow groomer, they could be put to work on little days, create great A frames, and employ the local stoners, all in one hit.
Mowgli, about radioactivity and big blue dongs, just checked and it's not blue. So I'm OK I think. Also, don't use FB so haven't seen it. The only FB link I've ever clicked on is "AU Falcons doing incredible things", which is pretty inspiring.

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mowgli Wednesday, 4 Dec 2019 at 10:41am

From memory the 30s saw some whoppa tropical storms so that may explain denuded beach systems in the 40s. The ones up here on hte sunny coast really only achieved a "recovered state" from the high cyclonic activity of the 70s in the '00s.

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velocityjohnno Wednesday, 29 Jan 2020 at 6:42pm

Stu asked me on the EAC article if I had seen Crikey's 'Collapsing Coast' series, linked here:

https://www.crikey.com.au/the-collapsing-coast/

Some reading to go through. Searching for it I came across a 2008 article from the other surf site:

https://www.coastalwatch.com/environment/4524/the-impact-of-coastal-eros...

Question: do any of you live near the spots in the CW article? Have they changed since 2008?

I'll get into reading all that above tonight. One thing I'm wondering Stu, would there be any benefit in identifying a 'control' beach that is not featured in development (or marram) or anything silly we have introduced? If so, how is that changing?

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stunet Wednesday, 29 Jan 2020 at 7:24pm

VJ,

I was a bit disappointed by the Inq coverage TBH. Thought it would be more in depth, you'll get a better analysis in our forums and comments.

As for a control beach: Maybe for future forecast changes - i.e sea level rise - but all the erosion to date is human-induced so not sure there'd be any purpose of control data?

Also, each example is very individual. Humans have found myriad ways to screw to coastal zone.

 

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velocityjohnno Wednesday, 29 Jan 2020 at 8:37pm

Agree, and that's a huge compliment to the information here at Swellnet!

As for the control beach, I was thinking of the one I sent you the pic of - no marram, very little human input, blowout present in the dunes, gradual slope presents opportunity of well defined and shaped waves. A long term view of this beach - which will be changing itself as the dunal plants colonise and then get wiped back - might give a better view of the sea level rise? Dunno if the land there is elevating or sinking.

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stunet Thursday, 30 Jan 2020 at 10:22am

Yeah, in terms of sea level rise, an untouched beach may be good. Though from what I understand, sea level rise will be erratic, not the same around Australia or the world, so perhaps it might come down to some places faring better than others irrespective of how original and intact it is.

Not sure, just spitballing.

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truebluebasher Saturday, 29 Feb 2020 at 1:37pm

Downunder Qldurr goes bananas at Troppo Climate Change report !

2011 Queensland Coastal Processes and Climate Change

Page 22 [ Qld Map ] > " Vulnerability to Varying Influence of Climate Change "

*SEQ - Minor Tidal Influence > (Minor = Drowning in a rising sea of 1-100 Floods)
*SEQ - Minor Cyclone Threat > (Minor = Sydney Cyclone Siren needs new batteries)
*Townsville - Minor Tidal Influence > (Minor = Noah: "Worst Flood ever on Earth!")

https://data.longpaddock.qld.gov.au/static/about/publications/pdf/qld-co...

Tbb advises to get a bigger Black texta & don't stop until all Of Qld is coloured in!

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velocityjohnno Wednesday, 27 May 2020 at 1:54pm

Coastal erosion after the Big Saturday and Sunday swell for NSW/QLD May 2020:

https://www.willyweather.com.au/news/12776/midcoast+council+issues+warni...

Down here in Vic we've had a good run of swell and I'm beginning to see the winter eating of the foredune (tall, upright foredune thanks Marram grass...) which seems relatively normal.

East Coast crew: anything radically different for your local after this swell?

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mowgli Wednesday, 15 Jul 2020 at 3:30pm

How are things looking around Sydney/Central Coast this week?

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truebluebasher Wednesday, 15 Jul 2020 at 8:00pm

Perfect Timing mowgli..
Stockton Erosion turned out to be a living local history treasure trove.
Grom refashions the Erosion & Lockdown into a 300y/old Time Machine

Council have equally cool "Story Maps" for the erosion.
https://storymaps.arcgis.com/stories/75f46591f216484597cdcafc14fd8131

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shoredump Friday, 17 Jul 2020 at 10:21am

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mowgli Wednesday, 23 Sep 2020 at 5:13pm

Thanks TBB.

The site is interesting....

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truebluebasher Friday, 17 Jul 2020 at 6:33pm

NSW Central Coast (Recent erosion + Up dates)

4th June 2020 ECL - Old Bar
https://www.nbnnews.com.au/2020/06/04/council-looking-into-another-sand-...

Wamberal
June 2016 ECL
https://www.dailytelegraph.com.au/newslocal/central-coast/major-erosion-...
July 2017
https://www.nbnnews.com.au/2017/07/23/wamberal-residents-meet-over-erosion/

29th May 2020 ECL - NBN [ Video 2 mins ]
https://www.nbnnews.com.au/2020/05/29/wamberal-residents-call-for-sea-wa...

13 July 2020 Pre ECL - (Massive Snow-Hail Dump) Central Coast.
https://www.nbnnews.com.au/2020/07/13/wild-weather-white-christmas-in-ju...

14th July - Big Bombora Sets [ 11.6m ] (Cowabunga)
https://www.facebook.com/abccentralcoast/posts/3740393542642794

(current) re: shoredump's photo..(Now a Big News Story)

17th July 2020 ECL

https://thenewdaily.com.au/news/state/nsw/2020/07/17/central-coast-erosi...

CCN TV : Lead Report
https://coastcommunitynews.com.au/central-coast/news/2020/07/weekly-vide...

Wamberal (7)news [10 min Video]
https://www.facebook.com/7NEWSsydney/videos/764108207673453/
[0: 45]
https://www.facebook.com/7NewsAustralia/videos/evacuation-warning-after-...

Bigger tides tonight...

Bonus : 2020 ECL (Blooper)
Avoca: One of Craig's puny 'infragravity waves' hits pay dirt...(Oh! The Carnage!)
https://www.facebook.com/abccentralcoast/videos/611200963141073/

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oxrox Monday, 15 Feb 2021 at 8:38pm

My local council in all their wisdom have started digging a giant ditch on the beach between the water line and sand dunes. They are then mixing the beach sand and cement with a hopper on the beach, laying the mix back on the beach, on a slope of 16 degrees apparently. Effectively turning part of the beach into concrete! They will then cover with sand (which will be washed off in winter) I am livid they have done this with no community consultation, or as far as I know, expert advice. Apparently, this is being done to protect the sand dunes from further erosion due to a road being in close proximity to the dunes. Stupid part is, with excavators and bobcats on the beach and all the digging, the dunes have collapsed and vegetation on the dunes has gone with it. One area is now a close to vertical drop 3.5m from the road. In my opinion, the road now has to be closed. I cant believe a beach is being turned into concrete to prevent coastal erosion. I can find no history or precedent of this happening anywhere. We are a small shire with no money, is the excuse for these works. (ie no funds for alternatives.) They have now spent $250 000.00 (federal government money to provide stimulus to local economy) to prevent potential erosion to dunes which they have now fucked with machinery anyway. I won`t name the shire but has anyone heard of this happening anywhere in Oz? I cant.

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velocityjohnno Monday, 4 Apr 2022 at 4:52pm
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Distracted Monday, 4 Apr 2022 at 9:24pm

Usual fluff in this Daily Mail link but the video footage from Avoca(?) is pretty nuts, lucky no one was hurt. Have to wonder what old mate drifting past on the foamie was doing!
https://www.dailymail.co.uk/news/article-10678453/amp/Monster-waves-batt...

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batfink Tuesday, 5 Apr 2022 at 12:42pm

Maroubra north end, not a grain of sand on it, just back to bare rock and a lot of seaweed. Haven’t seen that level of erosion before, not right back to the wall.

North end Soldiers Beach up cenny coast easily the worst I’ve seen in 30 years. Took all the sand from north end, cut into the dune to 2 and 3 metres, stairs were well built and have survived, cut into the sand under the clubbie boat ramp (mid beach) and while I was there a 3 metre slab broke off. The amount of detritus on the southern third is off the richter, including man-mad slabs of concrete weighing a few hundred kgs just deposited up the beach. Where did they come from? Enough wood for camp fires for about 10 years. Was a sight.

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AndyM Tuesday, 5 Apr 2022 at 12:55pm
Distracted wrote:

Usual fluff in this Daily Mail link but the video footage from Avoca(?) is pretty nuts, lucky no one was hurt. Have to wonder what old mate drifting past on the foamie was doing!
https://www.dailymail.co.uk/news/article-10678453/amp/Monster-waves-batt...

Daily Mail showing that they don’t know what a “king tide” is.
Would be interesting to see them have a chat with Thermalben about infragravity waves :)

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velocityjohnno Monday, 23 May 2022 at 9:09pm

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velocityjohnno Wednesday, 21 Sep 2022 at 10:53pm

https://www.abc.net.au/news/2022-09-17/la-nina-likely-to-intensify-wa-be...

this one's great - been on location recently and I'd do the whole citizen journalism thing but it looks like the local ABC is already all over it:

https://www.abc.net.au/news/2022-08-23/point-moore-coastal-erosion-geral...

https://www.abc.net.au/news/2022-09-17/sand-dunes-started-disappearing-a...

what I can tell you is there's a nice sea eagle nest on a pole nearby and it looks like parents are busy raising bub.

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velocityjohnno Wednesday, 21 Sep 2022 at 11:36pm

This one from 2016 reveals the consequences of substantial marina etc development, and that 12,000 cubic metres of sand are used yearly to stabilise the foreshore north of the port:

https://www.abc.net.au/news/2016-03-06/coastal-erosion-claiming-geraldto...

(That area has had rocky reefs, that break only in big swells, out the back for as long as I can remember, perhaps we can sculpt a left superbank of sorts)