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[box box]

i'd like to talk about building artificial reefs for coastal protection and surfing break enhancement. anyone?

[BlueBerry]

artificial reefs are like artificial t!ts to me... I prefer the real ones but I wouldn't discriminate against the artificial ones.


 

[surfplusart]

in the Gerry Lopez book (see book reviews) he mentions a bunch of breaks in Hawaii, a couple (?) that were created but also some good waves destroyed by us army corps sand-dumping operations, i can't recall if he mentioned artificial reefs... you might be able to find some info about hawaii somewhere...


i just did a quick internet search out of curioustiy... this came up, looks interesting.
http://blog.groundswellsociety.org/wp-content/uploads/07-Saving-Sandy-Hook.pdf

[BlueBerry]

Isn't NorthSt. The Sand Reef Expert. I mean that literally.

[box box]

^ right!

[RayG]

In actuality, many of the best breaks on the East Coast (other than some of the rocky pts of the NE) ARE "artificial". Many were created for "Coastal Protection" or "Erosion Control". Even NSSS can be considered an "artificial, man-made wave". Without the jetty it would be another shifty beach break. A well known northern NJ spot is a classic example, as is the lighthouse area around Hatteras. While they were created to protect the beaches, the waves were a happy accident of littoral sand movement. As for trying to design a purpose built permanent artificial "reef" in our parts- it would be impractical for the most part. The bottom material, in our case, is sand. Sand moves with any slight current or tidal flow. Setting up any kind of reef may work in the short term but will soon expose the flaws in placing one there. The sand will collect or scour over time in ways that are almost impossible to predict. What may happen is the sand building up in one place and scouring out a deep hole in another. Quality would soon be no better than what we have now. Or maybe worse. This, I think was the result at Pratte's reef in CA.
Now, in my opinion, a system of a series of Portable caisson type of structures a hundred yds off shore, maybe 100 yds long and 200 or 300 yds apart  that blocks predominant wave action is a better choice. Okay, so it may block some waves- BUT the waves that come through will be slightly refracted and create A-frames instead of 100 yd wide close outs. AND as the sand builds up behind the caissons, a series of semi circular sand structures are created. Once the beach is widened a certain amount, the caissons are then moved into the existing openings. The waves THEN come into these semi-circular projections and create a near 'Trestles' like peak that peels along with rights and lefts. this process can be repeated as needed along the beach and then moved back to the starting point. As an example- I think the Narrowneck artificial reef in Australia created the type of situation I describe. The beach behind the reef started to build up with no other help. I think this would use a more natural sand movement as opposed to another set of groins. It would also allow the sand to move ALONG the shore in a more natural flow, bringing sand to down beach locations. Another plus is the creation of structure for sea life, making for better fishing, bigger sharks which will then thin out the crowds.

[ChopChaser]

Flexibility is key
Flexible modular units that can be assembled or disassembled quickly to allow for easy trial and error testing of various depths and spots. I am currently a big fan of the geotextile bags, narrowneck only scratched the surface of their potential-could use some scaling up with more budget. I like the multi-faceted recreational aspects of the narrowneck plan form, snorkeling or kayaking/SUPing/hobie launch in the lee when its flat, when it is not flat the current between the textile mounds take surfers out to the peak. Balanced with some upland park planning a relatively inactive dead spot on the beach can offer something for everyone and help spread the crowd. Would be rad to create a submerged island just offshore so as to allow the natural littoral drift & sand migration to still occur between island and shore while buffering & splitting direct swell energy.

[nogasdrilling]

benefitting habitat is good, sharks and otherwise. see here NYC Subway cars dropped off NJ shore:
http://www.nycsubway.org/cars/redbird-scrap.html

and Delaware:
http://www.treehugger.com/files/2008/04/nyc-subway-makes-coral-reef.php

[Crackie "Bottle" Onassis]

From what I've read, which is little, the one in NZ Mt Mangaui (sp?) really didn't work out as expected.

[Northstreet]

RayG is correct, almost every sandy beach on the East Coast is artifical!
 
I'm not an expert, but I know some experts...
 
You can't make a reef out of sand without some hard structure to keep it there.  Most artificial reefs right now are designed with geotubes, or super big fabric or plastic sandbags to keep the sand in place.  This makes them semi-permenant.   Probably the biggest problem with getting too creative with these designs is very strict environmental regulations and the related permitting processes.
 
ASR Ltd. is the world leader in making these reefs 
 
http://blog.asrltd.com/
 
 
Still, with all of these designs, I only convinced that there has been limited success.  The reefs only work on certain swells, and really not that good.  Explore the ASR website for some constructed reefs.
 
ASR in fact, has designed an artificial reef for the NJ coast, but it has not yet been built.  It will be expensive to build, and money is a bit hard to find right now.
 
My favorite innovative design for a reef?
 
http://www.stanleysreef.org/
 
 
Otherwise, I'll take some nice sandbars with good grain size.  I do sometimes think about what it would take to make a cobble stone point break with tons and tons of nice river cobbles.   That would be very very cool.....
 
 
 

[RayG]

  I do sometimes think about what it would take to make a cobble stone point break with tons and tons of nice river cobbles.   That would be very very cool.....
 
 

How long would it take if each time one of us went east, we bring back a rock?

[talmai]

From what I've read, which is little, the one in NZ Mt Mangaui (sp?) really didn't work out as expected.

Mount Manganui  I was there 1 year ago. The reef sucks and it ruined the best beach break in the area. Now they are stuck with it because no one has the funds to remove it. I'm still in favor of doing something here on LI though. First hurdle is finding someone who will pay.

[Northstreet]

and as a really rough estimate just for the construction, think around $5M to start.

[ChopChaser]

Crackie there has not been a completely succesful Arf reef to date. We are getting closer each time. As long as each reef team learns from the mistakes and successes of previous projects progress will continue.

Northstreet what are your thoughts on reusing DOT cobblestones?

I also think electrolysis/calcified reefs are interesting, essentially chicken wire with low voltage current to mimic the natural reef building process of accretion. Kind of like the build up under your boat. To remove the reef you  just reverse the current and relocate the modular cages.
 

[Northstreet]

Chop:  Look at the Stanley Reef design, it's modular, adjustable to swells, and removable.
 
You'd have a tough time getting a state permit to "dump" old DOT cobblestones, or anything else that is not super natural-like.