Auckland port dredge estimates don't tally with disposal consent - iwi

Ports of Auckland. Photo / Brett Phibbs

Local iwi claim Ports of Auckland's proposed dredging of the Waitemata navigation channel will create more dredge waste material than allowed under its existing disposal consent, and that it has no concrete plans to deal with it.

Nor did the port's application reflect "cultural sensitivities" in relation to dumping of waste materials into different rohe, or tribal territories, a hearing panel deciding on the application heard today.

Of the 210 submissions on the proposed dredging, 99 groups actively oppose granting consent, 75 were concerned about the disposal of dredged material at Great Barrier Island or Cuvier Island, and 25 linked their issues to "adverse effects on the cultural values of mana whenua and other interest groups."

Ports of Auckland intends to dig the current 12.5-metre channel to a minimum of 14 metres, and the berth to 15.5 metres, to cater initially to ships with a capacity of 6,000-to-7,000 twenty-foot equivalent unit (TEU) containers. Its second stage will cater for new 'Panamax' container ships of close to 12,000 TEUs, with a maximum draft of more than 15 metres.

The port operator's capital works application includes removing an estimated 2.5 million cubic metres of seabed material from the Rangitoto channel and the Fergusson Wharf approaches over a 15-year period.

But the port only has rights to transfer and dump up to 400,000 cubic metres of dredged material to a dump site near Cuvier Island - limited in total to 2 million cubic metres over the next 34 years.

'Worst cast scenario'

A port spokesperson said the estimate represents a "worst case scenario" of the amount of dredging required. "The last time POAL undertook capital dredging, in the early 2000s, the company applied to remove 1 million cubic metres but in the end only needed to remove 600,000 cubic metres."

He told BusinessDesk that the volume of dredged material will not impact the first stage of the programme, only stage two, "which is some years away."

"The port will ensure that there is a legal disposal option in place before stage two commences, either via the designated disposal site or via an authorised alternative disposal option."

Iwi group Ngati Whatua Orakei said there was a serious cultural issue relating to the origin of the dredge material and plans to dump it in another rohe.

Ngarimu Blair, deputy chair of Ngati Whatua Orakei, said the proposed transfer of 2.5 million cubic metres of spoil from his iwi's rohe and "dumping it in the rohe of other iwi, in particular Ngati Wai and Ngati Rehua ki Aotea, without their consent, is deeply offensive to the tikanga of Ngati Whatua Orakei."

Blair said while a consent for dumping of dredge material already existed, the activity must be considered as a whole, and that the proposed dredging activity "would entirely account for, and exceed, the quantum consented at Cuvier."

The Ngati Whatua Orakei submission said that dumping of spoil will also have "significant adverse effects on the receiving environment, including despoiling of kai moana (seafood) and the "high risk of the introduction of contaminants and invasive non-indigenous species."