Beach Replenishment Question

[NJgeoman]

The Feds are spending a Gazillion dollars replenishing sand on New Jersey beaches all up and down the coast. The Army Corps dredges sand from offshore and pumps a slurry of sand and ocean water on the beach. I know that the slurry flows through pipes and a screen prior to being dumped onshore. How effective is the screen? Has anyone out there hunted these fresh sand deposits? Found anything unique? or does this additional sanding just bury the good stuff deeper.

Inquiring Minds Want To Know and while your thinking about it - don't forget to "Do The Boogie"
The Garden State Parkway Boogie!

http://www.youtube.com/watch?v=pLOZ42MfLC8

 

[D-Tex]

We had the same problem at Galveston after " IKE " washed sand from the beaches there, They pumped ( reported ) 500,000 cubic yards from several miles offshore

to build the beaches up 3 to 5 feet. That all but killed detecting for anything for several years, its all washing back out to where it came from so they will have to repeat

the process in a few more years. There have been a few good finds but there fairly new drops. it much the same story anywhere they do that from what I have seed and heard.

The screens they use only catch the larger stuff, that's to protect the dredge pumps.

 

[GeorgeinSC]

I am facing the same question at my favorite beach as they are making preparations to re-nourish. I have made some good finds where the ocean has eroded the dunes. It is a $200.00 fine if caught walking in or on the dunes and yes they do patrol.

There is a one city block area where I have dug up an unusual amount of clad along with two gold rings and two or three silver rings. The dune has washed away until there is a straight up and down wall that in places is six feet tall. I have made the finds up within 3-5 feet of the dune wall. I have wondered if the coins were there before the last re-nourishment or were they deposited there when they pumped the sand back. A lot of people would have been in the dunes to lose that quantity of coins.

They now have what appear to be some kind of buoys set about 2-300 yards off shore to mark the area that they are going to pump the sand from. At dead low tide this summer there were areas where one could walk out about 100 yards from shore and still only be in chest deep water. They have also placed poles with flags on the beach. I assume to indicate how deep the sand will be when they finish.

It will take two or three years for the ocean to remove a lot of sand but this beach does get a lot more erosion than most beaches due to the Charleston Harbor Jetties blocking the movement sand from the north to the south.

 

[Kossie]

On the Dutch coast beach replenishment is part of coastal defenses. It is repeated every 5 years on average. At first I was disappointed when a thick layer of sterile sand was deposited. In the Netherlands the sand isn't led through a screen or filter. After a while I realised that spots where the pipes end, can yield some nice stuff. I can recognise these sport by the large amount of iron objects, shells, pebbles an brick fragments. I've found 17th and 18th century hammered coins in fairly good condition, better than most that come from the inland fields. I've also found old copper gauges, motorcycle-lights, copper/bronze stuff from ships, lead net weights, a lot of 30 and 50 cal casings and bullets and 2 German artillery shells (including one with detonator, both where disposed of by the authorities). I suppose the screens filter out most of the coarse stuff but some of the best treasure comes in small sizes..This year a big replenishment is scheduled and I will definitely make the best from these new opportunities. After one season I notice no difference in yield but still hope for stormy north-westerns and high tides in the off-season to expose the older layers.

During the replenishing proces be aware of quick sand. You can observe the pipe-ends from a distance and come back later.

Greetz Kossie

 

[opa81]

n/t

 

[opa81]

Here in The Netherlands a new technique is used called Forebank Nourishment.

There is no longer a need for dumping sand right on the beach.

Here is some more info:

Andre

 

[KinTN]

I like that! Build up something like a barrier island to break up the incoming wave energy to protect the beach. Makes much more sense. Next step in this intellectual progression is to use rocks/riprap offshore so the energy wont move the protection away rapidly like happens with sand.
Neat info and pic, thanks for posting!

 

[EL Pulltabio]

A private company did the same thing where I detect six years ago.
Too bad I was relatively new to the hobby when they were here.
This is what I learned: They would use large bulldozers to build
a barrier against the incoming tide. That meant all the goodies
were either in those large walls of beach sand or sitting newly exposed
on the land side.
I showed up at night and started detecting apparently too close to the dozers.
They sent a foreman after me. He was a pleasant guy who explained the liability
aspects and risk that I was taking. I asked if I could continue to detect if I promised
to stay at least 75 yards away from the nearest dozer. He gave me the green light much to
my surprise.
What they pump in behind the sand wall from out to sea is worthless.
These guys worked only at night. During the day, they had everything blocked off with
barricades. If I had the machines and the knowledge I have today, I could have made out
like a fat rat in a cheese factory.
BTW, you'll be detecting the trash they leave behind for a long time to come.

 

[Fortuna]

We have the same thing here, you have to wait until the winter storms clear the sand away again