Storm water pollutes the Porirua Harbour. More than 70 stormwater outlets draining residential, commercial and industrial areas. Storm water is rainfall which runs off hard surfaces; roads, pavements, carparks and roofs and eventually into the harbour. Scientists regularly monitor the harbour for pollutants. Historically the harbour was also polluted with sewage from the old Porirua Hospital.


Why are estuaries important?


Why are the mudflats special?


How does mud effect cockles?


What else can be done to limit pollution in the harbour?












Urban Catchment


Pauatahanui Reserve




Creatures Great & Small


The Rural Catchment


Industrial Catchment


The Future

Episode information

What do I need to know about good kai moana (seafood) harvesting practices?

Maintaining the biodiversity of our waterways is what mindful harvesting of kai moana (seafood) is all about. Knowing the right practices and quotas (legal amount to take) makes all the difference. Learn more about the protocols for Shellfish & Finfish harvesting here.


Make sure you are aware of Te Angiangi Marine Reserve in Pukerua Bay too: link


The use of set nets in the Pauatahanui inlet is prohibited.


There are lots of answers to a range of foundational questions on safe shellfish harvesting in this document from Toi Te Ora – Public Health Bay of Plenty.


Foodsmart has some good information on assessing and storing shellfish.







How can I find out more information about the local iwi Ngati Toa?


Local iwi Ngati Toa have a website with information on their treaty documents, latest panui, grants and more.


This Treaty Settlement document between Ngati Toa Rangatira and the Crown explains the agreements about the governance of both Whitireia and Queen Elizabeth Parks.


You can also read this summary of the Letter of Agreement between the Crown and Ngāti Toa Rangatira for the settlement of historical claims.


To have a deeper understanding of the ancestral origins and acts leading to the settlement of local iwi Ngati Toa, check out ‘Iwi Origins




Is there still an Asylum/Mental Health Hospital in Porirua?


Since 1887 men and women in need of fulltime care have been looked after in Porirua. What was once called the Porirua Lunatic Asylum (‘luna’ meaning moon, and ‘tic’ meaning ‘you’re affected’) is now called the Ratonga Rua o Porirua Hinengaro Hauora, Mental Health Facility. Under the influence of Truby King in the 1920’s men and women worked the almost 1200 acre farm land.

Historical Information can be found at the Porirua Hospital Museum.

What is the stormwater system around the harbour way?


Have a look at this blog about water conservation, it contains a helpful explanatory diagram of the urban water cycle.


Where do your waters go? Find out more by watching this explanatory video about the sewage treatment.

What do I do if I see pollution going into the waterways?


It’s great to see people actively looking after the wellbeing of the Harbour. If you see anything inorganic that doesn’t belong there, you can take action by removing it safely, or call the Greater Wellington Regional Council Pollution Hotline (24hr) 0800 496 734

During office hours, you can also ring (04) 384 5708 for help.

Visit the GOPI site to read more about threats to our waterways like sedimentation, contamination and Eutrophication 

For more information on the types of pollution effecting our waterways like rubber off tyres, metals and CO2, watch the extended interview with Juliet Milne. 



What’s the best way to avoid causing contamination when washing my car?


Wherever possible, wash your car on the lawn using minimal water and soap (make sure it’s eco-friendly).


Some helpful information on best practices when washing your car can be found here.


What’s the best way to wash my paintbrushes/dispose of my paintwater?


Let the paint you no longer need dry in the tin send it to landfill rather than pouring it down the drain, or dilute it with water and tip it onto weeds/grass. Let the soil filter it rather than sending it out to sea.


For more information on good disposal options for household waste, follow this link to Save The Drain For Rain.


Ecobob is an extensive directory of eco friendly suppliers for all kinds of products, including paint.

What’s the best way to factor the environment into property development?


Whether you own or rent the properties you live and work in, or are involved with a building project, establishing and maintaining a healthy property which factors in the environment ‘down stream’ requires good research.


Lite-house has great links and information on sustainable architecture including household wind turbines


Graeme North has built over 100 buildings in rammed-earth, in-situ adobe, strawbale, cob and more. He also worked to establish the NZ Earthbuilding Standards (1998) and regularly runs practical workshops on sustainable architecture and design techniques.


Wellington City Council has established Sustainable Building Guidelines


You can also get in touch with an Eco Design Advisor for some free advice


Or the Sustainability Trust for healthy home advice and services like insulation, curtains and heat pumps.


The Sustainable Habitat Challenge (SHAC) is a national competition which challenges teams to build or retrofit a more sustainable house, building, office, classroom or community hall. Form a tertiary, industry, or community-led team, and work collaboratively, involve young people and communicate widely about your designs.


The Ecomatters Environment Trust in Waitakere in Auckland has extensive resources on sustainable living from water use to stream restoration, community gardens, collaboration and participation and more. 

How healthy is the harbour right now?


Find out more about the state of the harbour and ecological monitoring practices.


Watch the extended interview to learn more about measuring sediment quality, animals living in the sediment and identifying contaminants like DDT and heavy metals, as well as potential nutrient and organic carbon imbalances. Find out more about pollutants to harbour sediment like copper lead, zinc and DDT here.

Why do scientific measurements of estuary life?


Whether it’s cockles, carnivorous snails, bubble shells or seagrass, fine-scale sampling and measuring of the harbour’s biodiversity at specific locations helps us to identify fluctuations in harbour health over time. Check out the Wriggle website for more information on what’s involved

Who is responsible for cleaning up the litter?


Keep Porirua Beautiful is a group dedicated to restorative community projects like Cleanup Days, Te Maara at Cornwall (community gardens), Adopt A Spot, Murals and community education at local events like Creekfest.


Greater Wellington Regional Council, Department of Conservation, Ngati Toa Iwi.  Get involved with GOPI, KPB and other members of the community on the annual shoreline cleanup.


Tiny bits of plastic are arguably one of the greatest threats to aquatic life. Simple choices like reusable lunch containers, zero packaging and mindful disposal all help.

The Sustainable Coastlines crew have some good information on threats and links to Love Your Coast events all over Aotearoa.


Trash Palace is the local waste recycling centre. It’s a great hub for creative responses to waste, such as the ‘Funky Junk’ music band.