Natural environment

Natural Environment

We began our recovery from the severe drought in 2019/20 by improving the diversity of our water supply sources and reducing our reliance on rain-fed dams.

We have been working to increase the total volume of water available for Auckland. Our work to expand three existing treatment plants and build three new ones has meant that the water in our storage dams in the south and west has been conserved while we brought these new sources into service.

New, diverse water sources

In October 2020, we brought the Pukekohe bores back into service, treating groundwater at a new water treatment plant, to provide an extra five million litres of water daily.

The new water treatment plant has been designed in a modular fashion using equipment and containers built for different situations and other purposes, combined with custom-made components. This plant was designed, constructed and commissioned in just four months.

The next source to come online was Hays Creek in Papakura – a small dam which had been out of service for the past 15 years, due to the poor quality of raw water. Abstracting water from this dam and treating it to an extremely high standard, has added another six million litres of water daily, which would have otherwise been lost to the environment. The next stage of this project is on track to increase production by another six million litres by December 2021.

The last and biggest of our water supply augmentation projects is our new water treatment plant, the Waikato 50 at Tuakau, which can treat another 50 million litres of water from the Waikato River. This plant went into service in July 2021 and will make Auckland’s water supply more resilient to prolonged dry weather.

These new sources, along with the additional capacity enabled by upgrades at our existing plants at Tuakau, Onehunga and Waiākere will increase the total volume of water available to Auckland by more than 100 million litres of water a day. To put that into perspective, this is enough to meet the needs of 400,000 people (about the population of Palmerston North, Tauranga and Hamilton combined).

Reducing leaks

Our leak detection team has swept 5400 kilometres of pipes with acoustic technology, saving about nine million litres of water per day. The programme initially targeted areas with high numbers of reported leaks and will continue until all our 9000+ kilometres of pipes are surveyed. It is a key part of our efforts to minimise water lost to leaks.

When we find these invisible leaks in our network, we repair them and prevent the associated water loss. By repairing these smaller leaks which are normally invisible on the surface, we prevent larger leaks that can occur when the ground dries up and contracts, causing pipe movement and sometimes breakages.

While our dam levels were still about 25% lower than normal at the end of June 2021, our city’s water supply is in a stronger position. This is thanks to these new sources, continued reduction in leaks and the incredible efforts of our customers and communities in demonstrating the value of water.

Enhancing environment

We know our customers and communities place a great deal of value on clean harbours and waterways and look to us to act as guardians of the environment. We don’t take this responsibility lightly. Integrating environmental considerations into everything we do is key to our role as a trusted iwi partner and public utility.

Our activities are intrinsically linked to the health of the natural environment. We fulfil our environmental responsibilities through a regulatory framework (see page 23 for more details). Beyond compliance with consent conditions, we also further improve the quality of harbours and waterways through riparian restoration programmes, flora and fauna protection, and the use of advanced treatment processes to discharge high-quality treated wastewater.

The past year has seen us achieving a number of milestones relating to water quality:


We completed the $110 million upgrade to the Pukekohe Wastewater Treatment Plant, putting in place advanced processes that will enable the discharge of top-quality treated wastewater into Parker Lane Stream, a tributary of the Waikato River. This is an example of a sustainable solution that allows us to discharge treated wastewater into the environment economically and safely while catering for the growing population in this region, for the next 35 years. We worked in partnership with Te Taniwha O Waikato.

Western Isthmus

As part of the Western Isthmus Water Quality Improvement Programme, we are investing $412 million over 10 years to reduce wastewater overflows into the environment in this area and working with Auckland Council’s Healthy Waters department for sewer separation where there are combined stormwater and wastewater networks.


  • Design and consenting for the St Marys Bay sewer separation project continues in the Herne Bay catchment.
  • The Freemans Bay separation project is near completion with 1215 metres of new public stormwater network, separation of 16 dwellings in Picton Street and enabling separation of a further 61 dwellings in Anglesea and Picton Streets by diverting stormwater from the combined sewers into the new stormwater tunnel. This project also provides for full separation of an additional 74 dwellings in Franklin Road and Collingwood Street which are now connected to the new stormwater tunnel.
  • The Ōwairaka separation project (Oakley catchment) is near completion, with 1170 metres of new public stormwater network (delivered by Piritahi and Kāinga Ora/Auckland Housing Programme) and separation of 66 dwellings (currently in progress). Targeted/opportunistic separation projects include 515 metres of new public stormwater network installed in Bond Street (Motions catchment), Westmere Crescent and Winsomere Crescent (Westmere catchment) and 16 dwellings separated in Bond Street.
  • We are carrying out field investigations for separation in other areas including Herne Bay, Point Chevalier, Westmere and Blockhouse Bay.

Hūnua Ranges

We advanced native planting in the Hūnua Ranges, with another 115,000 seedlings in the ground (adding to more than a million in total for the last three years). One of the largest restoration projects in the country, its objective is to progressively restore this 1900-hectare former pine forest to native bush over the next 30 years.

Reduce and reuse

We completed the installation of New Zealand’s first-ever floating solar array on the treatment pond at our Rosedale Wastewater Treatment Plant. The one-megawatt (1MW) floating array is made up of 2700 solar panels and 4000 floating pontoons and has generated 1.23 gigawatts per hour (GWh) since its installation in September 2020. Solar generation is expected to form a large part of our energy improvement programme in the coming years. A key focus of our resource recovery journey is the beneficial use of biosolids. We have made notable progress in this area:

  • Since September 2020, we have been trialling a range of potting mix blends, using pasteurised biosolids as fertiliser for growing native seedlings. About 10,000 native seedlings are part of this nursery trial at the Māngere Resource Recovery facility.
  • Struvite, a clean sand-like by-product of the wastewater treatment process, has been used for formal turf trials and has produced very successful results both in seed germination and growth.

We will continue to expand these trials and work with Auckland Council and the wider industry to develop a market plan for the widespread use of treated biosolids for the horticulture industry.

NE Case study

Eden Park gets a helping hand

Eden Park – New Zealand’s national stadium has switched from using treated drinking water to bore water to irrigate its turf, thanks to a new custom-made water treatment plant and reinstated bore. Designed and supplied by Watercare, the new bore will result in projected water savings of 16 million litres of water per year (or the annual water use of 87 households) while ensuring that the turf is irrigated and kept in prime condition.

The historic bore has been out of service since 2008 because sandy sediment and minerals were causing major concrete stains and clogging irrigators. But now, the 25-metre-deep bore is pumping out up to 163,000 litres per day to water the turf. The bore revitalisation project began in May last year when water restrictions were introduced to combat Auckland’s severe drought.

We are looking to extend the bore water irrigation project to other locations and likely candidates include Lloyd Elsmore Park in Pakuranga – one of the largest sports parks in Auckland.