What sets Waiheke Marina apart?

By reference to the State of Our Gulf Report 2020, it is clear that the environmental impacts of marinas within the Hauraki Gulf Marine Park are modest. When considered alongside the ongoing impacts on the water quality of the Gulf caused by sediment, metal and nutrient run-off from land (caused by uncontrolled earthworks, untreated stormwater and farming), and over-fishing by recreational fishers generally, the impacts of marinas are not seen as a cause for concern.

Of the 9 or so specific references to marinas in the 2020 report (pages 16, 27, 85, 87, 92,156, and 164), most simply state the fact that marinas are a form of coastal/urban development and that the number of them has increased in the Park since 2000 (from 9 to 13), providing an additional 1500 berths over 20 years. Over this same period, the number of swing moorings has decreased, and the extent of dry-stack facilities increased.

As a form of urban development, what impacts do marinas have on the Gulf?

Impacts of marinas can be categorised into those physical/coastal process effects arising from their construction; and those arising from their long-term operation.

The biggest impact of marinas arises from how they are constructed. All marinas built in the Hauraki Gulf over the past 50 years have been created by excavating a basin within the sea floor (to create all tide water close to land), and then building structures around this basin to provide shelter from waves and currents. The structure of choice is usually a rock breakwater. In many cases, the soil excavated from the seabed to create the basin is then used to build a reclamation that is subsequently used for car parking and marina related activities.

These basins and new structures change coastal processes and currents. But there are no documented cases of such changes having significant impacts on adjoining coastal areas. This is because the potential for such effects has always been a key component of the environmental impact/assessment process for these developments – including back prior to the Resource Management Act 1991.

Because they are an area of sheltered water, all existing Auckland marina basins tend to accumulate sediment that runs-off from the adjoining land, or is carried into the marina on incoming tides. This fact is recognised in the 2020 report at page 87. To maintain water depth, all existing Auckland marinas need to undertake maintenance dredging (to differing degrees) and these dredgings then need disposal, with dumping elsewhere in the coastal marine area being the historically preferred option. Because boats that are in the water on a full-time basis are coated with antifouling applications that break-down overtime, this has also led to elevated levels of some chemicals and metals in the sediments in marina basins. These metals are disturbed and redistributed when maintenance dredging is undertaken.

However, apart from the impact of antifouling paints on sediment and water quality generally, marinas do not tend to give rise to other water quality contaminants, because the marina structures are not used for activities that could contaminate rainwater: when it rains, water running off the marina piers and pontoons is clean. For those marinas with reclamations or adjacent carpark decks, the stormwater run-off is also collected and treated before discharge. For this reason, water quality within marinas is high and supports an abundance of sea-life.

When it comes to marinas therefore, the key contaminants of concern are those associated with the boats that are berthed within them. But all antifouling paints able to be used in New Zealand are regulated by the Environmental Protection Authority (EPA). Over the past 20 years, the EPA has progressively ‘outlawed’ those paints containing the most toxic chemicals (e.g., tributylin, which was banned globally in 2008). The authorised antifouling paints that are able to be used within New Zealand are now predominantly copper based, but a range of new, ‘low-copper’ and even ‘no-copper’ antifoul paints are becoming available.

Taking a ‘full spectrum’ view of the potential effects of marinas, the only other effect of note relates not to the structures themselves, or even the boats, but the fact that marinas give people greater access to the Hauraki Gulf and some of those people enjoy recreational fishing. Similarly, some boaties take advantage of the fact that at a certain distance from the coastline, they are legally allowed to dump the contents of their black and grey water tanks into the water. So, at this level, marinas indirectly contribute to recreational fishing and wastewater dumping. It is important to note though that both these activities are also independently controlled by other regulations.

It is also notable that boat ownership in Auckland is a part of Auckland culture and continues to increase, but this increase is not correlated to the increase in marina berths. Based on the information in the 2020 report, marina berths in the Hauraki Gulf have increased at the rate of 75 per year for the past 20 years, an insignificant number when compared to the number of new boats launched into the Gulf over that same period.

So why is Waiheke Marina different?

The below table sets out the key construction related features of all of the marinas in the Waitemata Harbour, in order to compare them with the same features of the Waiheke Marina. By reference to the table, it will be seen that the design of Waiheke Marina is unique in a number of respects.

1. As the site is naturally deep, no dredging is required to build it, and no dredging will be needed to maintain it.
2. No reclamation is proposed. The marina is located 100m+ from the foreshore, and no disruption to the existing beach will occur.
3. The marina piers will be protected by state-of-the-art floating attenuators, not by solid rock breakwaters.

These features are important. In the absence of fixed coastal structures, and without dredging to build it, Waiheke Marina will have minimal impacts on the surrounding coastal environment. It will not disrupt coastal flows or currents, and nor will it disturb the existing foreshore. Its only attachment to land will occur adjacent to an existing seawall and road.

Similarly, while the Waiheke Marina will be home to vessels that will use antifoul paints to protect them, the conditions of consent and the Marina rules will require all boat owners to use low or no copper paints and this will be strictly regulated and enforced by the Marina owner. Waiheke Marina will take ownership of this issue and regulate it directly with berth owners in what is understood to be a first within the marina industry here.

Some other features of the Waiheke Marina are:

• The inclusion within the Marina footprint of a public pick-up and drop-off berth, able to be used by all of the boating public.
• A public grey and black water pump out facility to enable vessels that might otherwise dump their waste into the Gulf, to have those emptied and dealt with responsibly by the Marina.
• The availability of day berthage for visiting boats to use.
• Public walkways and accessible structures for recreation and amenity use.
• A public information/education centre and cafe/meeting space that will also be available for the general public.
• Public storage and launching facilities for kayaks and SUPs.

Lastly, to recognise the fact that it is occupying common marine area, the development company intends to establish the Waiheke Marina Maritime Trust, which will be a charitable trust set up for foster maritime education. The trust fund will receive funding initially from the company and then annually from berth holders. The Auckland Council does not presently have a policy on coastal occupation charging and so there was no obligation on the developer to offer this. However, the project resolved from the outset to acknowledge that it was seeking occupation rights in public space and that it try to address that. This initiative goes beyond legal requirements and is unique to Waiheke Marina.

Some Key Facts

• By and large, marinas are not a major threat to the health of the Hauraki Gulf.
• In contrast to all of the other existing marinas within the Hauraki Gulf, Waiheke Marina raises the bar in terms of environmental design and sustainability. It also offers benefits for the general public that are also presently unseen in any other Auckland marinas.
• The project will foster and enhance the relationship that people have with the Hauraki Gulf and create an opportunity for education about and stewardship of the Hauraki Gulf.
• The health of the Hauraki Gulf will be preserved because of the environmental design and the other controls that the marina developer has volunteered to put onto all of its future occupants and users.