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Disposal of dredged material

Ports of Auckland was granted a marine dumping consent EEZ400011 on 27 June 2019 for a period of 35 years. The consent will expire on 27 June 2054.

​The permit, granted by the Environmental Protection Authority (EPA) pursuant to sections 62(1)(a) of the Exclusive Economic Zone and Continental Shelf (Environmental Effects) Act 2012 (EEZ Act), authorises the disposal of capital and maintenance dredged material at the Cuvier Disposal Site (CDS) 27 nautical miles east of Cuvier Island.

The CDS disposal site is one of five disposal sites around New Zealand designated for the disposal of, amongst other things, dredged material. The CDS is beyond the Hauraki Gulf within New Zealand's exclusive Economic Zone. The location of the disposal site in relation to Auckland and the Coromandel can be seen in the attached ma​p. The dumping of approved dredge material is authorised within a circle of 200 metres radius cantered on position 36°28′S 176°17′E.

The marine dumping consent authorises the disposal of a total of 2M m3 of dredged material from capital dredging and 1.75M m3 of maintenance dredging at the CDS over the term of this consent at a maximum. The permit restricts disposal activities to no more than 50,000 m3 of dredged material from maintenance dredging, nor more than 400,000 m3 of dredged material from capital dredging, in any consecutive 12-month period.

The consent authorises only the disposal of material dredged by a barge-mounted mechanical excavator and disposed of using a bottom-opening barge at the disposal site.

Ports of Auckland's application and supporting impact assessment can be found here.

EPA's decision report can be found here.

Wh​y does Ports of Auckland need to dredge?

All ports are required to maintain notified depths to ensure that ships can navigate and berth safely. 

Ports of Auckland currently have two permits, issued by Auckland Council, authorising the removal of any natural sediment build-up from the seabed in order to maintain the notified depths within the port, the port's approaches, and in the Waitematā Navigation Channel. Under these consents, the port carries out a programme of regular maintenance dredging and removes around 50,000m3 of built up material annually.   

Ports of Auckland has also applied to Auckland Council to undertake a program of capital dredging to deepen the Waitematā Navigation Channel, the Fergusson North Berth and its approaches to enable the larger ships that will call in to New Zealand ports in the coming years.  ​

All Ports of Auckland dredging is undertaken using a barge-mounted​ excavator filling a bottom opening barge, either towed or self-propelled, as keen be seen in the image at the top of the page.  When full, the barge will be towed to the CDS site and the dredged material dumped via the bottom opening of the barge.

Marine Dumping Consent EEZ400011​

Condition 15 requirements

Condition 15 of the MDC requires that Ports of Auckland provide stakeholders access to information prepared as a requirement of the consent. Condition 15 states:

a) Provide the stakeholders identified in the Engagement Log Summary (Attachment 3 of the application) with up-to-date information on the activity authorised by this consent. This information shall include the results of any monitoring, and reports, required to be prepared by the conditions of this consent. ​

b) Make available the information provided to stakeholders under clause a) for the duration of this consent through a website maintained by the Consent Holder.

Information provided on this website

1. Dredged Material Sampling Plans (condition 6)​

The permit requires a comprehensive process of sediment sampling, testing, assessment and approval to confirm that all material is clean and safe to be disposed of at the site. This assessment process includes contaminant concentrations and biosecurity risks.   

This process is outlined in the diagram here.  It requires Ports of Auckland to prepare and submit a sampling plan for each area to undergo capital dredging or every 3 to 5 years for areas undergoing maintenance dredging. 

Approved sample plans are available here in the links section at the end of this page.

2. Dredged material quality assessment reports (condition 7).​​

Based on the approved sampling plan, samples are analysed and where required additional testing (elutriation, toxicity testing, bioaccumulation assessment or testing) is carried out to identify whether the dredged material is suitable for disposal at the Cuvier Dumping Site (CDS).  If EPA approves the assessment report for the particular dredging, the material may be disposed at the CDS.  If the report is not approved, the sediment cannot be dumped at the CDS.  Based on this process, the dredged material must meet minimum quality requirements prior to disposal.

Approved assessment reports are available in the links section at the end of this page.

3. Disposal records (Condition 16)

Ports of Auckland are required to provide monthly dumping records to EPA.

Disposal records are available in the links section at the end of this page.

4. Marine mammal observation records (Condition 21)

Ports of Auckland are required to provide monthly observation records to EPA.

Observation records are available in the links section at the end of this page.

5. Pre Dumping Seabed Survey (condition 23)

Ports of Auckland are required to undertake a survey of the seabed within the predicted northern sedimentation plume outside the CDS boundary to identify if any rare or vulnerable ecosystems, or habitats of threatened species, are present.  The survey is carried out in accordance with Condition 24.  Should the first survey identify any rare or vulnerable ecosystems, or habitats of threatened species, Condition 25 requires that additional surveys are conducted in subsequent years.

Survey reports are available in the links section at the end of this page.

When will Ports of Auckland start dumping at the Cuvier Disposal Site

Ports of Auckland are not planning to exercise this consent and dispose of dredged material at the Cuvier Disposal Site until at least 2021.

Ports of Auckland recently lodged an application for capital dredging of the Waitematā Navigation Channel, the Fergusson North Berth and its approaches with Auckland Council.  This consent is expected to be granted in 2020 and capital dredging commence in 2021.

Links:​

Please check back soon to view links 1 – 5.

1. Dredged material sampling plans (Condition 6)

There are no approved sampling plans at this stage. 

2. Dredged material quality assessment reports (condition 7).

There are no approved assessment reports at this stage. 

3. Disposal records (Condition 16)

There is no approved dredged material disposal at the CDS underway at this stage.  As such there are no monthly disposal records.

4. Marine mammal observation records (Condition 21)

There is no approved disposal underway at this stage.  As such there are no monthly marine mammal observation records.

5. Disposal site surveys (Conditions 23-25)

Pre-disposal survey

A pre-disposal survey as required by Condition 23 is being planned. The activity is Permitted (Regulation 5 of the EEZ) but requires that pre-activity requirements (information) are met. 

https://www.epa.govt.nz/industry-areas/eez-marine-activities/undertake-an-activity-in-the-eez/marine-scientific-research-prospecting-and-exploration/

The EEZ Act specifies the process that has to be followed (pre-activity information) prior to the permitted activity being undertaken. All pre-activity forms that have been completed for activities within the EEZ are available on the EPA website.

https://www.epa.govt.nz/industry-areas/eez-marine-activities/previous-applications-and-activities/marine-scientific-research/