Dredging Deception

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Below is a letter I wrote to the Otago Daily Times, they probably won't go near it, so posting here will give it some air

Dear Simon and Rebecca,

This is a private email to comment on your recent articles:

Economy v environment issue again

Harbour plans dredge up opposition

My name is Nicola Reeves, I am the South Island rep for Surfbreak Protection Society which is a charitable organisation dedicated to protecting surf breaks around New Zealand from inappropriate development, water quality issues and low impact access for all.

I have been meeting with Port Otago for 3 years in the Next Generation Projects' consultative phase. I submitted to the applications in August 2010. I was scheduled to speak to the submission on Thursday morning, but illness will not allow me to do so, Jayin Hutchings will be speaking on Surfbreaks behalf.

The campaigning of Surfbreak Protection Society (SPS) resulted in protecting 19 nationally significant Surf Breaks around New Zealand under Policy 16 of the New Zealand Coastal Policy Statement (NZCPS) 2010.

'The Spit' surf break at Aramoana is one of these surf breaks now protected, along with two other local breaks in direct line of sediment disturbance from the Next Generation Project - at Murderers and Karitane.

The Spit surf break has been directly affected since dumping began there in 1985, prior to then a world class wave still existed due to swell and wave refraction over the ebb delta at the mouth of the harbour. Detectable improvements in the peel angle of the wave due to the spoil mound has been recorded along with the potential for the destruction of the wave by continued dumping to an already full spoil mound.

Surfbreak Protection Society is very concerned about the actual and potential adverse effects that will or are likely to arise if this consent is granted for the proposed activity. This could result in significant adverse affects on the ‘wave environment’ and ‘amenity value of surfing’. The Council is required under policy 16 and 13 of the NZCPS to protect the Spit surf break.

Your articles indicate via wording and the graphic by Hayden Smith that the revised plan stage one dredged spoil from the capitol dredging 'Next Generation Project" of 500,000m3 per year, then 400,000m3 would be dumped at sea 6.5 K's out at the proposed new dump site 'A0'. This is not entirely correct.
The current inshore sites at Shelley Beach, The Spit and Heywards Point are the first and preferred disposal sites for stage one as stated in the recommendations report (march 2011), with the balance of spoil over 450,000m3 to be disposed at the A0 site. The currently owned dredges are not equipped to travel that far out to sea unless it is calm, as well as the prohibitive cost.

There is potential for 600,000m3 to be dumped at Aramoana over the next 3 years which will adversely affect the surfbreak.
The current statistics for spoil deposited at the Spit site over the last 5 years averages 32,000m3 per year. Reports published in 1998 and 2005 state that the dump site at The Spit is full, with a 43% retention of spoil per annum, and any further dumping would have a direct affect on the wave environment.

Experts in bathymetry and inshore wave science including information from reports commissioned by Port Otago have also indicated that the spoil site at The Spit, Aramoana is full, and further dumping has the potential to adversely affect the surfable breaking wave. A wave of this quality is a rare asset and has a great recreational and social and economic value.

The AEE report (May 2010) supplied with the resource consent applications state that there will be NO effect on the surfable wave at Aramoana and surfing in general.
This conclusion is ONLY based on the modelling for the A0 site 6.5 k's out to sea, NOT the CUMULATIVE effect of dumping at the current inshore sites. Where very obviously there will be a major effect.

PHOTO - The mechanism conducive to forming the surfable wave at The Spit Aramoana is created by a 'wave crest snap' as the swell rounds the ebb delta at the mouth of the harbour, the swell then moves over the dump site.
The spoil mound modifies the swell adjusting the peel angle improving the wave to a point, although energy is dissipated from the wave as it passes over the mound. A total absence of the spoil mound still gives a high class surfable wave with a slower peel rate and angle.

Unfortunately the presence of the ebb delta and offshore bathymetry creating the initial wave crest snap is artificially created by the construction of the fixed harbour mouth and mole built in the early 1900's and continual dredging of the harbour.