Inshore Dredging Disposal Consent Renewal

Port Otago is seeking a long-term consent for its inshore dredging disposal activity. Modelling and monitoring undertaken suggests an extension to the Heyward Point site and a minor adjustment to the Aramoana site could allow for better management of effects on nearby surf breaks.

Commencement of disposal at Aramoana - September 2016 Update

In accordance with Resource Consent RM11.153 Port Otago’s Dredge New Era has commenced disposal of sandy material from the Lower Harbour Channel and Entrance within the Aramoana disposal ground.  The disposal is likely to be completed by mid-September.

The disposal will be part of a “focussing mound” trial that has been agreed to by members of the Working Party.

Further information on this trial and the “focussing mound” can be found within  MetOcean’s Report: Proposed plans for dumping at Heyward Point and Aramoana Beach ground during the third quarter of 2016: P0140-05h-Dump-Plan-RevC.pdf 

Final Consent Application – July 2016 Update

We have now completed our final consent application and Assessment of Effects (AEE) for the long-term disposal consent.  The application has been lodged with the Otago Regional Council.  The consent is expected to be publicly notified on 16 July 2016 and submissions will be invited from the public.  Following the close of submissions, a hearing is expected to be held.

Our final consent application and AEE is available to view here.

Draft Consent Application - May 2016 Update

Port Otago completed a draft AEE for the long-term disposal consent in May 2016.  A copy of the AEE was circulated to stakeholders and available for comment. Some helpful feedback was received and a number of changes were incorporated into the final AEE submitted to the Otago Regional Council. 

Dredging Disposal Activity - Update January 2016

Aramoana Focussing Mound Trial

The majority of the 50,000m3 material for the “focussing mound” trial has been placed at the Aramoana disposal site during the period mid-Nov’15 to early Jan’16.  The trial that was agreed to by members of the Working Party with further information on the trial and the focussing mound able to be found within MetOcean’s Report:

Monitoring effects of the Q1-Q2 2015 disposal at the Heyward Ground and proposed dumping plans for Q3-Q4 2015 at Heyward and Aramoana Grounds.

The disposal area of the mound has been surveyed which has confirmed that the careful placement of material in the defined rectangular grid has achieved the desired shape to focus wave energy & improve the surf quality.  Analysis of the results and any feedback will be considered by the Working Party before any further decisions are made with respect a further 50,000m3 of material that is able to be used in accordance with the consents.

Heyward & Shelley Sites

Disposal from both New Era & Heron’s dredging works to the inshore sites is being managed between the Shelly & Heyward Point disposal sites depending on the material types and in accordance with restrictions and limitations within the consents. 


Port Otago Surf Survey - Aramoana and Murderers

This survey is being run by Port Otago Ltd to monitor the surfing wave quality at the north coast breaks near the Otago harbour entrance.

The purpose of this survey is to allow surfers to record their personal observations of surfing wave quality, which Port Otago Ltd will use to help inform their wave, hydrodynamic, and sediment dynamics study.

Take the survey here: www.portotagosurfsurvey.co.nz

January 2016 Update – surf survey still going

The surf survey is still going and you can still provide your feedback to us.  The number of incoming surveys for the last 6 months of 2015 was much slower than the period September 2014 to April 2015.  We are certainly still keen to receive your feedback and input.

We’ve put two reports on the www.portotago.co.nz website which present some results and analysis for the Sept’14 to Apr’15 period.  If you’ve got some quiet time at home, take a quick look at how the information you send us is being used.

Of real interest to us at the present time is the potential changes in surf at Aramoana, with 50,000m3 trial mound having been completed in mid-January.  Thanks again for taking the time to send us your feedback.

 

Overview of Dredging Disposal

Dredging has been carried out in the Otago Harbour since the 1860s, with disposal of dredged material “out to sea” occurring since at least 1882.  Prior to 1985 all dredged material was placed at the Heyward Point site.  This included material derived from both development and maintenance dredging.  In 1985, the Aramoana disposal site was first used.  The Shelly Beach site was added as a further option in 1987.  Sediment was placed here to assist in re-nourishing Shelly Beach, which was suffering from erosion at that time.

Otago Harbour is similar to other tidal ports around the world, as the channel and basin areas require ongoing dredging to maintained desired depths. Disposal at sea is the key economically viable way to dispose of dredged material.

 

Current disposal consent

Port Otago currently holds resource consent to dispose of up to 450,000m3 per year of harbour sediments derived from channel and berth dredging to three inshore disposal sites near the entrance of the Otago Harbour.  The current resource consent relates to the 81 hectares of coastal area across the three historical disposal areas of Heyward Point, Aramoana and Shelly Beach.

Resource Consent - Coastal Permit - RM11.153.01

This consent will expire in January 2017.  In order for the Port to be authorised to continue disposing of dredged material at these sites, Section 124 of the RMA requires that a renewal application be submitted to the Otago Regional Council, no later than 15 July 2016.  Port Otago is aiming to lodge its new consent application in June 2016.

 

Demystifying the dredging process

To help illustrate the dredging process, we've produced a short video clip showing the New Era working in the Otago Harbour showing the dredging process from start to finish: