Coastal erosion thread
https://www.abc.net.au/news/2019-06-13/port-beach-buildings-in-danger-af...
There was many a session here for me in the 90's and 2000's in the corner getting out of the wind, and just up the stretch arguably had the best winter banks the metro area could offer. The port was always doing work on the place, so I figured that each time they did changed the sand, leading to starvation upstream. Old timers said this area had great little waves before the North Mole (sp?) was put in.
The article suggests that sand dumping 1890 to 1970 is now over, so Sandtrax will be eroded out, and it's accumulating at Leighton. A pity, I fondly remember the pyramidal wedges that would break off the rock wall.
Hey Johnno,
Lots of Councils all along the Oz coast doing coastal management plans that take into account sea level rise. Basically, the higher MSL is, the further across the land storm waves can reach. Basic stuff. Here in QLD there's a big state run program going on called QCoast and there's something like 30 odd Councils involved in it, including the Gold and Sunny Coast councils.
No worries Mowgli. Since I posted the thread we've had the Port Beach article here at Swellnet which was pretty good crowd-research, and it appears to be a man-made thing; now it seems the sand supply created by the dredging of Freo port is running out, much like how the Councils and Ports have noted. Solution is a sand pipe line from offshore channels to create a Perth Superbank Left :)
Wide open ended thread velocityjohnno...allows for Saltwater preface.
Crew wish to acknowledge Saltwater people up front as their history erodes first.
Oz wide Aborigines retell greatest erosion tales of highest seas coming & going.
These local stories are the most telling oldest tales of Climate Change.
We know of Ocean Events depositing sea creatures into Lagoons.
Also of Rain flooding Rivers breaking seaward thru Spits then flooding bays.
Part man - part Sea Creature to survive. Of headlands rising & Sea receding.
A world of ocean wonder of singing to sea creatures from changing landscapes.
https://theconversation.com/ancient-aboriginal-stories-preserve-history-...
Aboriginal Rock Structures are again the oldest & perfectly wed all these worlds.
Estuarine & River Mouth Fish Traps reshape & advantage merging environments.
Such structures are accessed by Sea Companions & Community to Campsite
100's of ancient harmonious arenas co exist in the heart of our surf breaks
https://newmatilda.com/2019/02/05/australia-one-oldest-human-made-struct...
Oz wide Aborigines prided their designer seascapes with visiting communities.
Each Rock pool of varied catch adorns their Surf God like a garland as a banquet.
All encompassing Sea festivals of up to 5,000 visitors from 500 mile radius.
Saltwater crew tendered the estuary & befriended the life within the Ocean.
Everything had to play a part equally for all to benefit, mindful not to impact next.
Saltwater crew micromanage whole landscape in order to rejuvenate coastline.
Erosion: Seasonal Fires kill weeds & natives are replanted + full fishing rights,
Giving Saltwater crew full rights enables 100% recovery with ongoing resource.
Aborigines will fully support themselves & detox our coasts...A Win! Win! for all.
Examples of Saltwater erosion repair lies within Government partnerships.
https://coastadapt.com.au/sites/default/files/case_studies/CS08_Indigeno...
https://eatlas.org.au/nwa/indigenous/guide
South East Country is a major work as in keeping with other S/E natural heritage.
https://www.environment.gov.au/system/files/resources/271c0bfc-34a2-4c6c...
Thanks, TBB.
Big cultural impacts going on up in the Torres Strait too.
https://www.abc.net.au/news/2019-02-09/call-for-increased-flood-protecti...
I saw Mayor Gela speak recently and had a quick chinwag with him afterwards.
https://www.abc.net.au/news/2019-07-22/climate-change-affecting-property...
A link from those above. Long time wisdom from my family who are from this area suggests that a lot of the development that has gone on in the last 50 or 60 years is in places that traditionally flood or become inundated during extreme cyclones or rainfall. In that sense it shouldn't have been developed in the first place, as family members recount enormous flooding. Oh well...
Noosa replacing every little beach shack available with a resource sucking McMansion and encouraging tourists to cross the globe in order to crush load the place , all whilst moaning about climate change.
Put up or shut up.
Hahaha. Nice contribution to the discussion. Only very mild sarcasm intended on my part ;)
I owned a block of land on the NSW coast up until quite recently and sold it primarily because of the covenants on the land which dictated MINIMUM house size ( !!!!! ) and approved housing construction materials which mostly entailed resource heavy and high impact products. . One of the covenants was that no second hand materials were to be used. I had to fight hard to get an exemption for rammed earth sourced from the site .
The reasoning was that it was a premium “ dress circle “ parcel of land and that house values may suffer if I didn’t adhere to the mindlessly conservative fashion of rendered brick .
This is the kind of crazy shit still going on in a society which has declared a global emergency.
It’s all green wash bullshit right up until you brush up against the realities of greed. Noosa council is still actively promoting itself as a tourist destination in the complete understanding of the pressures that humanity places on the environment both locally and globally during the tourism process.
It’s hypocrisy.
If you are going to talk the talk you’ve got to be prepared to walk the walk. Otherwise it’s just more of the same hollow virtue signalling.
Wouldn't say it's "It’s all green wash bullshit right", that would suggest some overarching conspiracy, but it's more like multiple agencies with competing priorities.
the building covenants are determined by council yes?
This is a shire council housed in a single building we are talking about , not SMERSH*. They well understand what is involved and what’s at stake but if it compromises the river of gold via developers / fees / vested interests / lobbyists then it’s a sudden and terminal de prioritising of the environment.
*https://en.m.wikipedia.org/wiki/SMERSH_(James_Bond)
It was a 5 acre block adjoining a coastal national park ( littoral rainforest) . It had been grazed on for years with introduced tree species . I wanted to build a little rammed earth place and fit it out with second hand materials as features. Then I was going to allow the reintroduction of the native forest .
The council assumed I was going to bring the neighbourhood down with a Steptoe and son style existence. They’d never seen rammed earth....
So I tried to educate them . Showing them places I’d built in the SW WA where rammed earth is prominent and appreciated. Tried to explain why I wanted to minimise the footprint of the build and the impact of materials used and about my intentions to reinvigorate the block as habitat instead of turning it into a Jamie Durie / Bunnings / The Block wet dream complete with a high maintenance and waterthirsty lawn.
They gave me blank stares and slack jaws.
They also gave me a million reasons why it wasn’t possible or encouraged. I probably could have got some compromise by throwing stacks of money at them and their pet consultants but I chose to sell instead.
Too much expense and headache. The area now looks like the suburb out of Edward Scissorhands only wth bigger blocks and more agaves.
Top of the bubble .....time to get out.
Blowin
Did you ever have any issues with small black native bees digging into the rammed earth walls in W.A.
Here on the northern rivers of NSW they are a bit of a problem, I built a mud brick house making bricks that are 50% red clay and 50% sand and on one wall in particular the native bees started digging tunnels in the bricks and some of the bricks had so many holes they were like Aero chocolate. Some days there were a few hundred bees flying around next to the wall so I came up with the idea of using a vacuum cleaner with a flanged nozzle to suck them out of the air, I would have to do this for about 15 minutes each day mainly during spring.
The wall had the faint smell of honey.
My brothers mud brick house over in the next valley got attacked so bad he had to cement render all the outside walls.
The things you don't foresee when embarking on the owner builder journey.
I have also had big issues with termites getting into the floorboards via the pole frame.
Reckon if I built again with mud brick I would sit the poles up off the ground on big metal brackets and the mud brick walls between the poles would be sitting up off the ground on solid steel 'I' beams.
What shire does not allow rammed earth.
That's such a bummer Blowin, your intentions for the block were admirable. Reminds me of the SW WA surfboard collector not being allowed to develop a museum, so he casts (sells) the boards to the wind (other collectors). Such a shame.
Philo- Never seen a problem with the native bees on rammed earth . You’ve got to watch those termites though ! Admirable ambition when they are pursuing some tasty timber.
Those red clay bricks must’ve looked nice. Congrats on building your own home. I salute the effort.
Cheers.
If I was 30 years younger and didn't have a crook back I would love to explore some of the building ideas that are out there today.
Kevin Mcclouds Grand Designs program is a wealth of information, reckon I've watched all the episodes, as well as the Ozzie and NZ versions.
The latest building method that I am fascinated by is Air crete dome homes.
As you're probably aware, each State and Council has different regs. So that sucks they didn't have the foresight to support your ambitions, Blowin. When was this? Perhaps times have changed?
As I said earlier, compounding planning regs are also building codes which are insanely outdated and not fit for purpose no matter how you slice it. Here in SEQ there's not an insignificant probability that a direct hit/serious graze from a cyclone could occur. But QLD's building code only mandates certain wind velocity ratings for structural integrity down to around Bundy/Maryborough (there's a specific latitude I believe). So since the last busy cyclone period in the 60s though mid-70s, we haven't really had much (serious) action down this way. But it's only a matter of time. But a shitload of non-cyclone-ready development has gone on in the intervening 40 years...so yeah, if you thought the insurance payout figures the last few TCs up in FNQ were big...
Pciture of Clarkes Beach in Byron from early June. Quite a bit of erosion already there. I've seen and surfed similar in the past. Latest report sounds like much worse.
That line is 463m in length.
(hoping my imgur attempt works for once)
12 months prior and looking very nice.
Wow great images there Mowgli, very very telling. Wouldn't wanna tell us your source of them? Even email?
Those are really good Mowgli. I take it Google Earth wouldn't do such timely detail?
The website/service is called Nearmap. But you gotta pay for access.
They do developed areas. The more developed an area, the more frequent the imagery is taken. I'd like some of the more "remote" headlands up this way to have theirs taken just as regularly, but alas, a bunch of them are a couple years old now.
Banks up at Noosa are pretty ace at the moment. This image was taken last week (24 July). My mate said that recent swell gave the sand on main beach a bit of flogging.
Very nice!!
All been a bit ordinary up the road in terms of banks IMO...
Again, great pics
Lots of winter swell (continuous it feels) has led to sand erosion on the local back beach and there are many rocks to navigate getting in and out of the water at present.
The weather pattern responsible seems to be a near constant westerly flow which bends offshore locally, so I expect the local sand is being heavily re-organised by wave action while not being affected by strong onshore winds.
I've heard a couple of people say that a dive site created in recent years has changed local sand, but that bit is beyond my level of local sandflow interpretative skills at present.
Recent WA article : https://www.abc.net.au/news/2019-07-31/erosion-washing-away-beaches-up-a...
Great story, those places are my formative surfing years. The birds of the Gero Marina are coming home to roost, to the north. Wonder what woes all the sand mining at Southgates will inflict on Mahomets in 20 years?
Australasian Coasts & Ports 2019 Hobart 10-13 September 2019
Conference Themes.. Index (Plenty of listed papers cross reference wave action)
Note: Some rare photos & Leading edge Papers are presented at conference
These are purely introductory papers but demonstrate today's best ocean science.
More like a Yearbook Encyclopedia of Australasian coastline activity...(Very Good)
https://coastsandports2019.com.au/
1.Port Planning & Development
2.Dredging Management,Community & Ecosystem
3.Coastal Processes in Coastal Ecosystems
4.Breakwaters & Erosion & Flood Mitigation Coastal Structures
5.Monitoring instrumentation & information Systems
6.Beach Nourishment & Shoreline Protection
7.Upgrade of Port & Marine Assets
8.Dredging Management,Community & Ecosystems
9.Coastal Processes in Coastal Ecosystems
10.Breakwaters & Erosion & Flood Mitigation Coastal Structures
11.Monitoring,Instrumentation & information Systems
12.Blue Economy
13.Ports & Marine Facilities
14.Dredging & Reclamation
15.Climate Change Adaption
16.Coastal Risk & Management
17.Coastal Response to Extreme Events & to Climate Change
18.Blue Economy: Marine Renewable Energy
19.Ports & Marine Facilities
20.Shipping Navigation & Port Operations
21 Sediment Transport,Sediment Processes & Morphology
22.Tides,Storm Surges,Long Waves & Tsunamis
23.Coastal Response to Extreme Events & to Climate Change
24.Shoreline Management
25.Ports & Marine Facilities
26.Shipping Navigation & Port Operations
27.Coastal Meteorology,Storms,Tropical Cyclones & Extreme Events
28.Tides,Storm Surges,Long Waves & Tsunamis
29.Recreational Facility,Waterfront Development & Marinas
30.Shelf & Shallow Water Wave Dynamics
31.Ports & Marine Facilities
32.Upgrade of Port & Marine Assets
33.Sediment Transport,Sediment Processes & Morphology
34.Breakwaters & Erosion &Flood Mitigation Coastal Structures
35.Recreational Facilities,Waterfront Development & Marinas
36.Shelf & shallow water wave dynamics
37.Ports & Marine Facilities
38.Upgrade of Port & Marine Assets
39.Coastal Processes in Coastal Ecosystems
40.Tides, Storm surges, Long Waves & Tsunamis
41.Recreational Facilities,Waterfront Development & Marinas
42.Shoreline Management
43.Ports & Marine Facilities
44.Shipping Navigation & Port Operations
45.Sediment Transport,Sediment processes & Morphology
46.Breakwaters & Erosion & Flood Mitigation Coastal Structures
47.Recreational Facilities,Waterfront Development & Marinas
48.Beach Nourishment & Shoreline Protection
https://coastsandports2019.com.au/wp-content/uploads/CP2019-Conference-E...
Reason for posting...
tbb believes these papers only last briefly then are shopped thru 3rd party.
So grab yer fav' paper now, while conference window is open...just saying!
Thanks for that TBB.
Nick Carroll has written a pretty good article over at another surfing site, linked as I think he's echoed Stu's contention that a lot of the breakwalls created waves and thus benefited us. Now, are they turning on us?
A little read of the Blacksmiths part suggests the port dredging a channel creates a long term starvation to its north, much like Freo ports and Sandtrax.
https://www.coastalwatch.com/surfing/25758/nick-carroll-the-breakwall-di...
Any NSW crew with anecdotes?
not a breakwall, but tamarama has never been the same since they removed the roller coaster and elephant (alice)
Regarding the Blacksmiths breakwall and Swansea Channel I can attest to it being an excellent wave (at times) 30 years ago. (Needs a NE swell and Sth quadrant winds). At low tide you could walk more than half way out on the north side with sand against the break water. At times you could catch a wave from out in the channel across the front of the break wall and end up half way down the beach, a good few hundred metres ride. They did extend the break wall a bit which may have effected the sand flow, but for the most part the sand has completely disappeared from the north side of the break wall.
From Blacky's breakwater north for about half a km another thing that may have had an effect on the sand banks is the dedication to sand dune stabilisation All you get now is vegetation growing right down to near the water line with a very short and rapid descent to the water level. Where once there was a 50 m stretch of sandy beach there is now barely 20m. The banks have been totally shite for a long time now.
WOL thanks for the insight, so it might be a case of marram type grass hoarding all the nice sand that makes good banks, and growing tall, close to shore?
I suspect dune blowout and native vegetation building a very gradual slope is the key to good shaped beachies in Oz. We can fix it but we're going to need a lot of VW chassis dune buggies, bonfires, beach parties then replanting the native plants when hungover in the morning.
And chook that's an unreal photo, I can't believe they actually built something that fun in that place. Looks amazing.
Cheers vj, ive got a photo of what I'm talking about and will put it here later.
Chook, unreal photo. How long ago was that photo taken?
Taken a couple of years ago. In the foreground you can see how much vegetation there is now where once there was sand.
In the top right corner is the end of the break wall, about 500m south. From memory this area was planted only with the grass, and over time this allowed the bigger shrubbery to become established. On this day at the end of the track the gently sloping sandy beach of the past was now part of the sea.
Unfortunately the surf zone has been attacked on two, and in some cases three, fronts.
Where hard structures impede sand flow upstream, then beaches downstream lose historical sand volumes, resulting in deeper banks and the ever-present threat of erosion, and where marram has replaced spinifex then more sand is removed from the surf zone and locked onto the beach, again making for deeper banks.
Sometimes those two forces work in tandem, and Blacksmiths sounds like one such place, the problems are exacerbated.
Unfortunately I cant see anything changing soon. There are a few forces at work, however the protection of expensive coastal real estate will remain paramount.
The third front effecting historical sand flows is more hypothetical and stems from recent reading on coastal sand mining. The volumes mined from the Myall Lakes area, Boomerang and Blueys, Crescent back beaches, Hat Head, and Tweed coast over the years 1950 to 1970-ish were staggering and even though much of the sand was taken from the secondary dune systems I wonder how that loss influenced sand flow.
I mean, we know now that dune sytems are always in flux, exchanging sand between the beach and the sea, and all those locations where rutile was mined are on the east Australia sand transport system.
Erosion "mitigation" works in place at Ocean Grove. Ramp being replaced and retaining wall being extended East towards Pt Lonsdale.
All I can see happening is the erosion being moved further down the beach. After the retaining wall was built erosion on high tides with bigger swells undermined the dune face and threatens to undermine the car park.
Equipment can be seen in the OG cam.
There's usually a bit of a current that develops at roughly the location of the ramp, heading east. If you're lucky, there might be a left out the back...
If they extend the retaining wall they will increase the erosion toward Pt Lonsdale. It seems to be the lesson they refuse to learn.
If you have a look along Whites Beach also on this coast, you will see steep eroded dunes (its the end of winter though) with the marram all through it. Further east, the native veg seems to take over in the first swale, but the marram is in the foredune.
When I become dictator of the Australian Republic many of you want, first thing I'll do is revoke titles to 1st row waterfront property in areas of poor beachies, then tear the lot up with heavy equipment leaving sand, cull all marram, leave for 10 years to the wind and make a big mess, then replant with native veg. Eventually it will look a bit like Supertubos in Portugal, only with more dune blowout because my henchmen will trash it with dune buggies from time to time to produce a low gentle slope, and epic beachy barrels.
How they ever decided dune blowout was a bad thing I'll never understand?
Stu: re the sand mining on NSW mid - I have some knowledge of that coast, is there any comparable 'control' coast in NSW that you can use to compare it with?
Stu, not sure if the sand mining actually took away large volumes of sand as the percentage of heavy minerals is quite low. But in the mining process they dug huge holes for the dredges and moved massive amounts of sand around....and then did massive revegetation programs with bitou bush and natives. As discussed above that revegtation may then have had other impacts on the banks.
Be hard to find a control site on the North Coast as so much was mined. Maybe Evans Head where the Air Force firing range is might not have been mined?
pretty sure Evans was mined
Would NSW south coast, with all its rocky headlands and beaches formed between, be a different type of coast for sand flows compared to north of Newcastle? AFAIK the QLD coast on the way up do DI point was mined, as very many colours of sand & minerals were found (the only one not was blue or green??) My gran gave me a glass bottle filled with all the colours when I was little.
Slightly related, was once working on a processing plant in this kind of area. Was very impressed with huge rotating cylinder heated at 1200C, doing something to the sands I guess. Some samples had a natural radioactivity iirc and there was the odd moment someone from the radio lab would phone back and ask "You didn't touch that one too much? It was pretty 'hot'!". Anyway, I asked the onsite crew what the end product was used for, and one use they mentioned was as a food additive!!!
Sand on the NSW south coast is largely trapped in the embayments; if a beach is eroded, the sand is generally lost offshore and gradually accretes onto the same beach - or one very close by.
Consider the different coloured sand at Palm Beach, Whale Beach, and Avalon on the far northern beaches of Sydney. It's more of an orange/apricot colour than the blonde sand found elsewhere in the Sydney basin, yet if longshore drift played a part then all the sand would be mixed together and be one homogenuous colour.
The south to north conveyor of sand doesn't start until the Hunter, but then really doesn't kick in till north of the Coffs region.
I can think of two long beaches on the NSW south coast that have a section called "sand mines" or to some "sand pits", presumably they did excavate the sand at those locations, in the dunes close to shore. Another (shorter) beach is called "sand mines". All three usually had pretty good banks back in the day (post mining).
Macauleys Beach here in Thirroul wasn't mined, however it was mismanaged and it's indicative of what occurred at many other places up and down the coast.
In 1973 they put the sewer on at Sandon Point and Bulli, so the Water Board had to run a pipe from Thirroul. The shortest route was through the then-extensive dunes at the southern end of Macauleys. The Water Board dug up all the dunes, trucked some of the sand out and shifted some of it further back into the shallow valley well off the foredune.
In May 1974 huge storms hit and without the dunes to buffer the coast the waves ate into the coastline irrevocably altering its shape. Anecdotally, about 50m of land was lost and the waves at Southy, so the old boys say, have never been the same.
There was an upside of sorts, as 25 years later the skeleton of Kuradji man was found there, detailing a history of the area that was to that point unknown. Without the removal of sand and subsequent erosion it's unlikely the skeleton would ever have been found.
@ vJ
Did you touch the radioactive sands? Where were you ? More importantly , what were you doing ?
This is a great insight into sand mining...
http://willkemp.net.au/enviroscience/land-degradation-and-rehabilitation...
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.