How on-land activities impact our harbours
Stormwater, wastewater, litter, sediment and heavy metals all eventually end up in the harbours, and impact on their ecology. This compromises the things we value about the marine environment, like clean beaches, safe water for swimming and abundant kaimoana.
Sediment run-off from the land has a significant impact on streams and on the marine environment. Excessive sediment generation blankets important habitats, like seagrass meadows and shellfish beds. Sediment also affects water clarity, making it less pleasant for swimming and affecting plant growth.
Nutrients, especially nitrogen and phosphorus which are key components of fertiliser, have serious impacts as they can increase algae growth.
Impervious surfaces in our urban environments, like roads and carparks, collect heavy metals such as lead, nickel and zinc, which are quickly washed into streams and stormwater systems and then into the marine environment when it rains. Heavy metals are toxic to both people and animals, even at relatively low concentrations.
Even the relatively low population density across Auckland, and the infrastructure that supports it, has had a significant effect on our marine environment. As the city grows, develops and intensifies, we need to embed new ways of managing its impacts.
In some cases, growth is a great opportunity to improve the downstream impacts of land uses choices, for example, by improving how we manage and treat stormwater and wastewater.
In other cases, it creates additional pressure, with increased sediment generated during development, and more impervious surfaces resulting in more contaminants being washed into waterways.
Waste from urban areas also has an impact on marine environments.
Just like other contaminants, waste such as plastic bottles and packaging are easily transported downstream, eventually ending up in the sea. This waste affects many species, including birds, fish and marine mammals. It also reduces people's enjoyment of the marine environment.
To protect and enhance these special places we need to take a 'ridge to reef' approach, recognising that everything that happens on the land has a downstream impact.
Hauraki Gulf and Waitematā Harbour
Auckland's east coast is defined by the Hauraki Gulf and Waitematā Harbour. The Hauraki Gulf is internationally recognised as a significant marine environment.
In 2000, the Gulf's importance and diversity of uses was recognised by the creation of the Hauraki Gulf Marine Park. The marine park designation is for the protection of nationally and internationally important environments and recognises the Hauraki Gulf's quality as a habitat for species unique to New Zealand. Read more about the Hauraki Gulf Marine Park Act 2000 on the New Zealand Legislation website.
The Hauraki Gulf supports diverse uses from aquaculture to tourism and recreation. Some of its islands, in particular Waiheke, support high levels of tourism, and some, such as Hauturu / Little Barrier, provide pest-free habitat for threatened species. The islands are treasured icons of the region.
The Gulf's beaches are loved as places to swim, surf and walk.
The range of habitats, from intertidal zones to open sea, provide habitat for species as diverse as shellfish, snapper, dolphins and whales, and the Gulf is an internationally significant seabird habitat.
Four marine reserves in the Hauraki Gulf also protect habitats and provide recreational opportunities, such as snorkelling at Goat Island in the Cape Rodney – Okakari Point marine reserve. Find out more on the Department of Conservation website.
Auckland Council monitoring and research has tracked the impact of urban areas on the marine environment. The upper Waitematā, in particular, shows the stress of years of urban run-off, particularly through heavy metals in sediment, increased muddiness and high levels of E.coli bacteria at beaches, making them unsafe for swimming. Some beaches are now permanently closed for swimming.
Find out if your beach is safe for swimming.
Kaipara Harbour
Auckland's west coast, home to rugged black sand beaches, is also home to the Kaipara and Manukau harbours. The Kaipara is New Zealand's largest harbour, with over 800 km of coastline. Auckland Council and the Northland Regional Council share responsibility for the harbour.
The remediation of Kaipara Moana (Kaipara Harbour) received a funding boost of $100 million in 2020 to stop farm run-off and improve water quality. Learn more about the Kaipara moana remediation programme.
The Kaipara is formed from a system of drowned river valleys, and is broad and shallow, famous for its unpredictable currents, shifting sands and treacherous entrance.
The Kaipara is home to diverse habitats, like seagrass in the shallow, upper reaches that support young snapper, and high current environments at the entrance that attracts large predators.
The Kaipara's catchments are mostly rural, with agriculture and forestry land uses dominating. There are however, urban and future urban areas, like Kumeu, Huapai and Helensville within the catchment.
These towns are forecast to grow and expand over the next 30 years. The key pressures on the Kaipara are sediment accumulation, E.coli bacteria and nutrient runoff.
Manukau Harbour
Further south, the Manukau Harbour shares lots of similarities with the Kaipara, such as a significant tidal range and shallow form.
The Manukau's catchment is significantly more developed, with urban and industrial land use affecting its quality.
The Manukau supports a range of habitats for shellfish, fish and seabirds, and is fringed on its north-west corner by the Waitakere Ranges regional park, a significant environmental and recreational asset for the region.
Managing the pressures on our marine environments
The health of the harbours is an important element to Auckland's overall success in protecting the environment.
The choices Auckland makes about where and how we develop on the land, has a direct impact on the health of our harbours. The Auckland Unitary Plan seeks to protect and enhance the marine environments, through setting rules for what activities can occur where.
Alongside that, there are other programmes underway which aim to improve the health of our marine environments. Auckland Council's water quality programme provides an overall framework for driving better water outcomes, for which a protected and enhanced marine environment is a key goal.
The following are some examples of programmes underway:
A collaborative Marine Spatial Plan for the Hauraki Gulf: SeaChange Tai Timu Tai Pari
This plan was produced by an independent working group, and released in December 2016.
SeaChange is non-statutory and non-binding on any organisations. The plan sets an ambitious vision, aiming to ensure that the positive health of the Hauraki Gulf is the key planning objective for all activities in the gulf and in all its catchments. The objectives of the plan provide a basis for collaboration between organisations active in the Gulf.
Essential Freshwater management tools
The Government has established the Essential Freshwater Package to restore and protect the health of our waterways (rivers, streams, lakes and wetlands).
The package includes:
- a new National Policy Statement for Freshwater Management (NPS-FW) 2020
- a National Environmental Standard for Freshwater (NES-FW)
- stock exclusion regulations
- amendments to the Resource Management Act relating to the Measurement and Reporting of Water Takes Regulations
- faster freshwater planning processes
- mandatory farm plans.
The programme's objectives are to reverse past damage, stop further degradation of freshwater resources and improve water quality within five years.
Integrated watershed plans
These plans are developed in partnership by the Auckland Council and local communities. They are designed to improve both freshwater and marine environments.
The plans are based on assessing the current state of catchments, the values and goals that the community identifies for the catchment, and take into account their implementation cost.
Improving our freshwater environments has direct, downstream impacts on marine environments. The plans are being developed progressively for each watershed.
Improvements to infrastructure
Improved infrastructure delivers better outcomes for our marine environment. As Auckland's population has grown, there has been increasing pressure on wastewater and stormwater networks, resulting in the systems overflowing, severely reducing marine water quality, limiting the number of days it's safe to swim and affecting the safety of kaimoana.
These networks also struggle to cope with the volumes of litter they must trap.
Watercare's asset management plan
Watercare's asset management plan details how it will upgrade the water and wastewater infrastructure to improve environmental impacts and to keep up with forecast population growth and urban spread. Auckland Council management of stormwater infrastructure is detailed in the Stormwater Asset Management Plan Summary.
