Narrowneck Artificial Surfing Reef

Narrowneck artificial reef, 'the twins' photo courtesy Gold Coast City Council

Narrowneck: Surfers Paradise, Gold Coast, Queensland, Australia

Latitude: 27°S

Aspect: east

Foundation: sand

Wave climate: estimate, 92% of days greater than knee height, 22 to 25 days per year overhead (Qld Coastal Services)

Swell direction: predominantly east to southeast (Qld Coastal Services Data)

Typical wind pattern: morning calm/westerly offshore, afternoon sou'east seabreeze side-onshore

Other: significant longshore drift (sand) to the north

In late 1999 a ‘multi-purpose artificial reef’ was built at Narrowneck. The reef is primarily a coastal protection structure, as the Gold Coast experiences ongoing issues with beach erosion and shoreline retreat during storm events. Officially, the secondary objective of the reef is to ‘improve surfing’.

The Narrowneck reef actually consists of two reefs. The twins sit side by side, two underwater ridges aligned perpendicular to the shoreline (shore normal) when viewed from above. In shape and form the reefs could be two submerged groynes/jetties. The reefs are made of more than 400 geotextile bags filled with sand, ranging in size from 3 to 4.5m in diameter and 20m long. Some of the bags needed replacing and a further 50+ bags were added over the following ten years. The structure has experienced minor settling and re-arrangement, mostly in response to severe storm episodes. The sand sausage bags have proved durable, the structural integrity solid.

The reef was designed by Dr Kerry Black (then Professor at Waikato University in New Zealand) with close support from two of his senior students Dr Shaw Mead and Mr Jamie Hutt. Dr Black went on to establish ASR Pty Ltd and design reefs at Mount Maunganui, Opunake and Bournemouth. Dr Black is a highly respected coastal scientist familiar with computer modelling. In 2009 he reviewed the project, Gold Coast 10 year anniversary (pdf 622KB). Dr Black feels the project was successful as a coastal protection structure. In the 20 page paper, surfing conditions are reviewed in the final two paragraphs of the last page.

Highly respected authors (Jackson, McGrath, Corbett, Tomlinson, Stuart 2007) of a paper reviewing the Narrowneck Reef (pdf1251 KB) suggest the reef has been effective as a 'control point', preventing further beach erosion and stabilising the shoreline. The authors maintain the reef has a positive impact in widening the beach and provides a buffer to storm events. They estimate waves ‘break’ on the reef 50% of days.

"The computer design for the reef (upper panel) and a reef survey at the end of the main construction phase after December 2000 (lower panel). In the light of this survey .... the built shape remains substantially at odds with the computer design...". Image and comments from pg8 of Dr Kerry Black's 2009 paper.

The secondary objective of the reef was to ‘improve surfing’.

How popular is the reef with local surfers (boardriders/bodyboarders/longboarders)? Has the reef improved surfing conditions? A key indicator of reef popularity with local surfers would be: % of days per year the reef is surfed. This question should be easy to answer because Narrowneck is monitored by permanent surf cams focused on the reef, see www.coastalwatch.com

Official monitoring of Narrowneck includes a large technical report every 6 months to analyse shoreline erosion and accretion trends using coastal imaging (essentially a technique to analyse and quantify onsite webcam data). The WRL November 2008 report (Blacka, Anderson & Lopez) is 160pages long, though it does not include any qualitative or quantitative assessment of 'improved surfing'. The same data has not been used to monitor the presence of surfers on the reef. Why not? Given that the secondary objective of the reef is to ‘improve surfing’, perhaps it should be. (For example, in 1999 a simple methodology using web cams to determine the popularity and consistency of a surf spot was developed by Bancroft to monitor the Cables Artificial Surfing Reef.)

How do the local surfers value the reef at Narrowneck?

There has been no official, nor formal post-reef consultation with local surfers to monitor the secondary objective of the reef. (For raw and 'unfiltered' opinions from others, see web blog comments on www.wannasurf.com). In this void, since 1999 Andrew Pitt has conducted 50+ interviews with local surfers, on and off site, surfed the site on six occasions, surf checked the site on 20 occasions and regularly monitors the surf cam. In the course of writing this article Andrew Pitt consulted with local surfers, circulating the early drafts of this paper to twenty individuals and 11 local boardrider clubs for comments and suggestions.

The above sampling suggests the following:

the reef at Narrowneck is rarely surfed
approximate estimates suggest the reef at Narrowneck is surfed 10% to 20% of days per year, far less than the 50% of days the reef ‘breaks’
when the reef is surfed, it is on clean east and south east swells, taller than chest high, with the righthander off the tip of the reef nose providing a quick breaking wave that peels a short distance
larger waves break on the outer sections of the reef and peel, while smaller waves break on the shallower inside section and do not peel at all.
the sand banks to the north of the reef, and in the lee of the reef, are more consistent and more popular with surfers post-reef than pre-reef (review of WRL coastal imaging indicates consistently better banks to the north)
The channel between the two parallel reefs is rarely used as route to paddle out
The reef has produced isolated days of glory, web video on www.youtube.com is an epic day, though it also indicates a sand bank formed on the north of the reef, this is not a regular occurrence.
a semi-permanent topographically controlled mega-rip + deep trench is apparent on the southern side of the reef, this issue is bigger than 'scouring'.
The local Lifesavers prefer to set up their red and yellow flags to the north in the lee of the reef, indicating a safer swimming environment.

Why is the reef not popular with surfers?

Let’s start with the design concept of 'twin reefs'. This is original, very so. Was the design inspired by naturally occurring surfing reefs? Or 100% computer inspired and generated? On the East Coast of Australia, research (see www.surfingramps.com.au/eastcoast) indicates there are more than 226 recognised surfing reefbreaks and 26 bombora-controlled-beachbreaks: not one of these naturally occurring reefs is a ‘twin reef’ arrangement. The question is, on review of surfing reef bathymetries worldwide - does a 'twin reef' arrangement exist in nature?

The thinking behind the original design concept was to provide a deep gutter between the two reefs, to act as a ‘channel for water and surfers returning seaward’. This design feature needs to be questioned for three reasons:

‘The Surfers Code' (pdf 1.8MB) a policy developed by Surfing Australia clearly states ‘Paddle Wide: when paddling out, stay wide of the break, away from other surfers’. It’s poor surfing etiquette to paddle out through the middle of a break, jumping the queue, going to the head of the peak, see ‘Do not snake’ in The Tribal Law (pdf 59KB) a Code of Ethics developed by Robert Conneeley (see Education at www.surfingaustralia.com ). Furthermore, it is extremely unwise and unsafe to paddle out through the middle of the wave breaking zone, central to all the wave energy, risking a clean-up set on the head as the twin reefs narrow.

Do you really want a channel running between your wave breaking zone, churning up the water in the take off zone? That’s what appears to be happening, all this choppy, agitated water in and around the whole reef.

The biggest question is, do you really want the feature of the twin reefs to dissect advancing wave lines? Each advancing wave line is cut by the channel, right hander one side, left hander the other side, creating two peaks that virtually compete against each other, pulling each other apart, with bumpy water all around. The opposite occurs at naturally occurring surfing reefbreaks on the east coast: most have one submerged ridge, amplifying each wave line over the ridge, creating one consolidated and unified peak. To 'split the peak' is different from dissecting the peak.

Who cares? Does it matter?

Surfers care. For that reason, elected members of governement should take note.

There are more than seventeen local boardrider clubs on the Gold Coast, most have a healthy membership, are organised, knowledgeable and in communication. All are passionate about their local breaks. In the course of writing this article, local surfers constantly referred to other coastal works on the 40+km stretch of the Gold Coast. A pattern began to emerge. A series of coastal works and proposals that have been of questionable long term benefit to local surfers, including:

the Tweed River Entrance Sand Bypass Project (TRESBP) which provides beach nourishment (pumping sand) to Duranbah, Snapper and Kirra. In the first years of operation the project (unintentionally) created the short lived 'Superbank'. However by early 2009 a local community group organised a 1500 person 'protest paddle out' to 'bring back Kirra' (www.kirrapoint.org). Some local surfers want the Kirra groyne re-installed.
beach nourishment works creating 'ephemeral reefs' (temporary sand banks by pumping or dumping sand onto the shoreline) with no clear method to improve surfing, reinforcing longshore bar (close-out-banks) instead, see Gold Coast Shoreline Management Plan.
in response to ongoing beach erosion and shoreline retreat during storm events, the Palm Beach Beach Protection Strategy (PBBPS) suggested building offshore reefs. The proposal was rejected by the local surfers who felt it would not improve surf, and felt it would also harm existing breaks (Burleigh) by disrupting the longshore drift of sand.

The positive news from long time Gold Coast local Andrew McKinnon is that 2009 could be a turning year, with government consulting more closely with local surfers for the removal/ excavation method of sand from Kirra and the nourishment/dumping of same sand to the north at Palm Beach (personal communication July09).

This issue is bigger than the Gold Coast. Surf and beach lifestyle define Australian culture, it's our international brand, our heart and soul. Surf and beach is the driving force of the local tourism economy, surf-industry and job creation. For these reasons, for authenticity, in the national interest, the local suburb called Surfers Paradise should indeed be a surfers paradise.

The Gold Coast City Council (GCCC) built the reef at Narrowneck, one of the objectives of the reef was to ‘improve surfing’. To demonstate accountability, leadership and restore community confidence, Council should deliver on the promise.

To increase the number of surfable days on the reef at Narrowneck, Gold Coast City Council should investigate the cost/benefits of the following maintenance works:

Unify the twin reefs as one reef; install more sand sausages and infill the channel

The reef is ‘sucking dry’ on the bigger days because there is not enough 'pre-conditioning' of advancing waves: install more sand bags to extend the nose of the (unified) reef ridge a further 100m seaward, bearing of the ridge should be more SouthEast, not east.

Extend the length of ride with more peel angle: install more bags off the northern reef hip, to create at least two inside sections on the right. Again, the footprint of the reef should be aligned more SouthEast, diagonal to the coastline.

Furthermore, officially monitoring needs to include the presence/absence of surfers on the reef using surf cam data. What happens AT the beach is just as important as what happens TO the beach.

Conclusion: the suggested maintenance works will assist Gold Coast City Council to fulfil the official secondary objective of the reef, to 'improve surfing' and present no negative impact on the existing beach protection strategy. In the national interest, Surfers Paradise should be a surfers paradise.

Acknowledgements; thank you to the following people for providing comments, suggestions, corrections and critique; Graham, Ken & Michael MNM Boardriders, Narrowneck Longboard Club, Bruce Lee, Andrew McKinnon, Neil Lazarow, Jonny Martin, Gary Wilson, Dr Kerry Black, Dave Skelly, Greg Stuart, Angus Jackson, John McGrath, Dr Shaw Mead and the many local surfers who provided blunt and candid opinions.

Photo courtesy of Mick Edwards and International Coastal Management (ICM)