Durban is slowly becoming a seaside city without any sand

[ponder]

That pic on the article, you can see the reason for Durban's beach disappearing. To build that wide walk way, they had to throw rocks and paving there, therefore, less beach. Same happened at Strand(Somer-Set West).

Nope, it was pretty much always that wide, the piers have been there for yonks and have not moved. Walkway is/was existing land and they did not reclaim beach to build it. Go look at some old arial photos going back to 19voetsek and you'll see it did not change over the years.

https://www.petitions24.com/help_save_our_beaches_and_save_tourism_in_durban_south_africa
Not so long ago,

That grey building on the beach in front of the swimming pools is the pumphouse used to pump sand onto the beaches.

Now,

That's the very same pumphouse

Blame the useless cadres,

All of this has happened due to complete ineptitude and lack of understanding of maintenance. The pump house, which was used to pump sand on to the beaches which would wash down and keep them full, has not been maintained, fallen to ruin and died an untimely death.

http://www.durban.gov.za/City_Servi...neering/Pages/Durban_Sand_Pumping_Scheme.aspx

Durban Sand Pumping Scheme

The Sand Pumping Scheme is operated to provide about 280 000 cubic metres of sand to the beaches every year (equivalent to the amount of sand eroded from the beach annually). Any sand over and above that quantity which is pumped onto the beaches will aid in regaining beach width lost in previous years.

The sand used for the scheme comes from the Dredging Services (Portnet) dredger, whose prime function is to maintain the harbour entrance. The dredger removes sand from the sand-trap area mentioned earlier and discharges about two in three of the 2 500 cubic metre loads into a Council owned concrete storage hopper near the North pier. The sand is subsequently re-dredged from this hopper by means of equipment housed on a mobile bridge which injects water from a nearby jet water station into the sand to loosen it, sucking it up and pumping it to the first booster station

From there the sand/water mixture can be boosted to four other stations along a pipeline which runs northwards as far as the Somtseu Road stormwater outfall. Along the route, the four booster stations maintain pressure, and the sand can be discharged onto the beaches from any one of a number of outlets situated along the beachfront from Addington to Bay of Plenty beaches.

The booster stations are approximately 700 m apart and the pumping main is a HDPE pipe of 400 mm OD Class 6. The system has been designed to deliver a maximum concentration of 30% by volume. The total length of the pumping main is about 3,5 km and the entire scheme is automated and controlled from the hopper site. The power and signal cables run along the beach along the same route as the pumping main. The Dredging Services dredger delivers about 2 500 cubic metres of sand into the hopper, which has a total capacity of 5 000 cubic metres at a time.

The quantity of sand received into the pumping scheme depends on the weather, so in extremely rough conditions no dredging can take place at all, and on the availability of sand in the sand-trap. In addition to the sand received from the maintenance dredging of the sand-trap area, the dredger is also chartered by the Council to provide additional sand by dredging from off-shore and placing into the hopper.

The sand-pumping scheme was completed in 1982 and up to the end of December 1993, has already delivered 2,500,000 cubic metres of sand to the worst affected areas. This quantity is in addition to an initial fill of 650,000 cubic metres of sand pumped directly to the beaches in 1982 as a one-off contract with an international dredging company.

19voetsek,

 

[Mila]

Doesn't it have to do with the harbors that were created?
the tides and flows that are altered ?

 

[KleinBoontjie]

The harbour having an effect? Would you mind explaining that a bit?

I don't know that area or how the harbour was built, but I can imagine that building walls in the sea, might impact how the currents flows. So the sand might wash away quicker or build up more.

Or,.......you know....flat earth and everything.

 

[KleinBoontjie]

Doesn't it have to do with the harbors that were created?
the tides and flows that are altered ?

mmmm, beat me to it, didn't see your post.

 

[ToxicBunny]

I don't know that area or how the harbour was built, but I can imagine that building walls in the sea, might impact how the currents flows. So the sand might wash away quicker or build up more.

Or,.......you know....flat earth and everything.

Durbans beaches are naturally very small, the wide beaches we've all become used to are artificially expanded through sand pumping and pier placement and such....

 

[Desig]

Clickbait

 

[blowdart18]

Thanks @Ponder, you don't have any pics / videos of the actual pumping station in action ?

Cannot search at work because of the firewall, will see what I find at home

 

[konfab]

The harbour having an effect? Would you mind explaining that a bit?

The water in these areas forms part of a complex-non-linear system. If you change one thing (lets say by disrupting the wave flow in a certain direction with the expansion of a harbor wall), you will cause an effect on the surrounding areas. Since we are talking about geography here, the timescale is very slow.


http://www.marbef.org/wiki/human_causes_of_coastal_erosion

If you want a visual example, look no further than this image:

http://www.grantpitcher.com/wp-content/uploads/2017/11/durban-harbour-inland.jpg

You can clearly see the harbor having an effect on the calmness of the water.

 

[Kosmik]

The water in these areas forms part of a complex-non-linear system. If you change one thing (lets say by disrupting the wave flow in a certain direction with the expansion of a harbor wall), you will cause an effect on the surrounding areas. Since we are talking about geography here, the timescale is very slow.


http://www.marbef.org/wiki/human_causes_of_coastal_erosion

If you want a visual example, look no further than this image:
View attachment 507305
http://www.grantpitcher.com/wp-content/uploads/2017/11/durban-harbour-inland.jpg

You can clearly see the harbor having an effect on the calmness of the water.

To be honest, thats the bluff having that effect and it always has. Thats why south beach beaches are far calmer than the northern ones.

 

[ToxicBunny]

The water in these areas forms part of a complex-non-linear system. If you change one thing (lets say by disrupting the wave flow in a certain direction with the expansion of a harbor wall), you will cause an effect on the surrounding areas. Since we are talking about geography here, the timescale is very slow.


http://www.marbef.org/wiki/human_causes_of_coastal_erosion

If you want a visual example, look no further than this image:
View attachment 507305
http://www.grantpitcher.com/wp-content/uploads/2017/11/durban-harbour-inland.jpg

You can clearly see the harbor having an effect on the calmness of the water.

Except that the harbour wall on the bluff side has not been extended in over 30 years... so its impact is not new by any stretch of the imagination... this issue currently being experienced at Durban is a combination of factors, the sand pumping not being as effective, sea level rise, more intense storms more frequently... If anything its nature trying to "fix" what we humans have tried to change.

The widening of the entrance was achieved by moving the other harbour wall out...

 

[ponder]

Thanks @Ponder, you don't have any pics / videos of the actual pumping station in action ?

Cannot search at work because of the firewall, will see what I find at home

Unfortunately knot, will keep looking.


This is how they did it in 1937,
[video=youtube;8cP9NjlYBkg]https://www.youtube.com/watch?v=8cP9NjlYBkg[/video]

 

[konfab]

Except that the harbour wall on the bluff side has not been extended in over 30 years... so its impact is not new by any stretch of the imagination

What do you think the timescale for ocean activity is? I would place it closer to the centuries mark than the decades mark. For example, there is an 18.6 year long lunar cycle that affects the height of tides, which in turn affect the way the sand moves about. This is also why taking action against it is so difficult.

The reality of the problem is that people assumed that beaches are static and immovable. That is the exact opposite of what they are. They are heavily affected by wind and tide. That is what should have been taken into account when determining the limit people can build near the ocean.

 

[qscwbt]

https://www.iol.co.za/dailynews/new...each-sand-to-replenish-durban-beaches-1988989

Durban - Transnet National Ports Authority (TNPA) is due to commence dredging and beach nourishment in Durban as soon as certification is issued by the South African Maritime Safety Authority to the new Ilembe dredging vessel.

A pipeline from the harbour mouth pump station, buried under the sea sand, has already been set up on Addington Beach.

eThekwini Municipality requires TNPA to provide 500 000 cubic metres of sand annually to reinstate the city’s beaches situated north of the channel mouth, due to the natural migration of sand along the coast, said Moshe Motlohi, TNPA’s Port of Durban Manager.

“Dredging is responsible for sustaining Durban’s famous beaches because the prevailing winds and currents cause a northward movement of sand (known as Littoral drift),” Motlohi explained.


“In order to prevent this sand from compromising the port’s entrance channels, dredging creates sand-traps and pumps the sand back to the northern side to mimic the sand’s natural progression.

This allows for nourishment of the beaches. Without this, the beach would be eroded.”

The Ilembe dredger will be tasked with reclaiming 150 000 cubic meters of sand during the upcoming dredging campaign.

Motlohi said the duration of the sand pumping would depend on a number of factors, including weather conditions.

The Ilembe, which will be undertaking this work, arrived at the Port of Durban in January after being built for TNPA in the Netherlands.

Motlohi said thereafter the Ilembe was scheduled to be deployed to East London.

Motlohi said the eThekwini Municipality was responsible for the safety of the public on the beaches during reclamation.

However, when the Daily News visited the site on the beach, an excavator was busy churning up the sand.

A huge, crater-sized hole filled with water was underneath the mouth of the pipe.

Caution tape flapped in the wind, barely visible, with a sign saying ‘beach closed’ on either end.

There were no signs on the promenade warning the public of possible dangers.

The eThekwini municipality had not responded to questions from the Daily News by publication deadline.

 

[ToxicBunny]

What do you think the timescale for ocean activity is? I would place it closer to the centuries mark than the decades mark. For example, there is an 18.6 year long lunar cycle that affects the height of tides, which in turn affect the way the sand moves about. This is also why taking action against it is so difficult.

The reality of the problem is that people assumed that beaches are static and immovable. That is the exact opposite of what they are. They are heavily affected by wind and tide. That is what should have been taken into account when determining the limit people can build near the ocean.

Except in the case of Durban we've made signifcant changes to the coast line in the last 100 years to get larger beaches.. and the effect where almost instant... these effects are also relatively rapid and the harbour itself isn't a major contributor to this change...

 

[schumi]

City's plan to save Durban beaches

AN EMERGENCY plan to replenish the sand on Durban's rapidly eroding central beaches is set to begin within the next four weeks.

eThekwini Municipality said its plan to focus on the central beaches and beaches near the Pirates Club and Suncoast Casino was necessary to prevent any further damage to infrastructure.

Warnings have been issued for high tides and the municipality is on high alert.

Municipal spokesperson Tozi Mthethwa said the city was engaging with Transnet Dredging Services to find ways in which the beaches could be replenished as current sand pumping could only go as far as Addington Beach.

“They (Transnet) have recommended a temporary offshore pipeline with the dredger discharging sand directly on to the beaches.

"We have a plan in place to nourish the central beaches via the offshore pipeline, using the dredger to directly discharge on to the beaches,” Mthethwa said.

The municipality said it does not pay for the sand received from Transnet and neither does it pay for the use of the dredger, which it shares with other cities such as Richards Bay and East London.

More at : https://www.iol.co.za/mercury/news/citys-plan-to-save-durban-beaches-13992079

 

[Pox]

Why not dump some more of those Dolosse there in those areas? How much do the Dolosse cost?

View attachment 507189

Yzerfontein Harbour wall. Been going there in holidays for 30+ years. The original wall was a lot thinner and about half the length. The monster there now makes the Harbour a lot safer but it completely changed the surf conditions on the main beach.

 

[ToxicBunny]

I was at vetches on Wednesday and I’ve never seen the beaches that wide... I could walk around ushaka pier and just get my feet wet

 

[Dave]

https://www.news24.com/Green/News/p...ming-a-seaside-city-without-any-sand-20180315

From the link

Communications head Tozi Mthethwa said the city had employed several strategies to combat the effects of climate change and overmining of sand.

"These include ensuring that beach sand washed out by the currents is swept back by municipal employees on a daily basis".

The guy couldn't really have made that comment, surely?

Sand washed out by the currents is swept back by municipal employees? What? With a big broom and scuba gear?

 

[schumi]

Durban beaches sand replenishment operation under way

Durban - City engineers and a private contractor, Suntech, have reacted swiftly to the threat of sand erosion on the North Beach promenade and lifeguard tower.

Since Friday, sand has been pumped from a dredger to the affected beaches.

Engineers had fitted a pipe to the dredger anchored a few kilometres offshore.

The sand is then pumped from the dredger into the pipe which has an outlet on one of the affected beaches.

Hundreds of curious onlookers took photographs and filmed the sand replenishment operation yesterday.

More at : https://www.iol.co.za/dailynews/news/durban-beaches-sand-replenishment-operation-under-way-14647168

 

[schumi]

R15 million 'emergency bill' for Durban beach repair scheme

Five Durban beaches are finally getting a badly-needed infusion of sand – but the emergency operation will cost ratepayers at least R15-million in extra costs because of lengthy failures by the municipality and Transnet to repair the city’s sand-pumping scheme.

Last week‚ a massive black plastic pipeline‚ reminiscent of a giant sea serpent‚ began to spew out a slurry of sea water onto the severely-eroded remnants of North Beach.

Over the next three weeks‚ the temporary ship-to-shore pipeline will be shifted to four other beaches - Dairy‚ Suncoast‚ Country Club and Sunkist - to replenish the sand and also prevent Durban’s popular promenade from washing into the Indian Ocean. All these beaches will be closed off in stages and then re-opened as the sand pumping and levelling process proceeds.
The massive operation follows severe erosion over recent years exacerbated by the equinox spring high tides in February.City officials have sought to blame the erosion on climate change and the proliferation of illegal sand-mining operations in several KwaZulu-Natal rivers‚ but enquiries by TimesLIVE suggest that the immediate cause has been the ten-year delay by Transnet and eThekwini Municipality to reinstate an extensive land-based sand pumping network that was commissioned in the early 1980s.

Largely because the massive Durban harbour entrance piers prevent sand from moving up the coast to replenish naturally eroded beaches‚ the municipality has been pumping sand onto local beaches for several decades. This is acknowledged on the city’s own website‚ which records that the first artificial sand replenishment scheme began in 1935.

However‚ early schemes did not solve the erosion problem and eventually a major 3.5km pumping scheme was designed by the Council for Scientific and Industrial Research (CSIR) to ensure that dredged sand could be pumped from the harbour as far north as Minitown.

More at: https://www.timeslive.co.za/news/so...mergency-bill-for-durban-beach-repair-scheme/