Assets and infrastructure


Assets Infrastructure

Planning for the short, medium and longer terms is integral for our business. Whether it is today or 20 years into the future, our customers and communities expect us to continue providing safe and reliable water and wastewater services at a fair price. Maintaining and building the right assets, at the right time and in the right place, is key to fulfilling our service commitments.

The past year has been notable not only for the infrastructure projects we have delivered but also for the way we have delivered them.

Delivering strategic assets

In 2020/21, we progressed and delivered almost all of our water supply augmentation projects, adding to Auckland’s supply capacity by more than 100 million litres per day (MLD) at an investment of $224 million. While these were in response to the 2019/20 drought, they will also boost the region’s overall resilience during the coming years.

In addition, we advanced several of our long-term projects across Auckland:

  • In May 2021, we installed the final pipe on section 11 of the 31-Kilometre-long Hūnua 4 Watermain, one of our largest strategic water infrastructure projects. This project began in 2010 and on completion will ensure security of supply to Auckland and cater for growth. Parts of East Tāmaki, Manukau and Māngere are already being supplied by it and the full watermain is expected to be in service by December 2021.
  • We received a resource consent to carry out earthworks and vegetation removal for the proposed Huia Water Treatment Plant replacement project from Auckland Council. This is an extremely critical project for our customers as the existing Huia Water Treatment Plant was built in 1928 and is nearing the end of its operational life. We will be replacing it with a new plant capable of treating 140MLD, which is 30 million litres more than the sustainable production capacity of the current plant. As Auckland’s water utility, we face three main challenges – population growth, ageing infrastructure and climate change. Assets and infrastructure How we’re delivering value The new water treatment plant in Tuakau Value created Future-proofed growth and supply assurance High-performing infrastructure This project will cater for our region’s growth and improve the security of the water supply.
  • We advanced the construction of the Central Interceptor, a 14.7 Kilometre-long wastewater tunnel. This $1.2 billion tunnel is the biggest wastewater project in New Zealand history and will help to clean up central Auckland’s waterways. Progress on this project during 2020/21 included: construction of the two main shafts at Māngere and May Road; start of micro-tunnelling at May Road for one of the link sewers; arrival of the main tunnel boring machine (TBM), Hiwa-i-te-rangi, from Germany and its assembly ahead of tunnelling underneath the Manukau Harbour. Tunnelling started in August 2021.
  • We completed stage 1 of upgrades for Pukekohe Wastewater Treatment Plant – this is part of our work to cater for growth and improve environmental outcomes in this area.
  • Work progressed on other strategic projects including North Harbour 2 Watermain (to cater for growth and add resilience); Northern Interceptor (to cater for growth and balance the network); and the Huia 1 and Nihotupu 1 watermain replacements (to ensure service continuity and add resilience).

Low-carbon thinking

The scale of our infrastructure programme is enormous, as it should be, to cater for a growing population. This carries huge implications for increased emissions as we continue to build new installations. So our focus in the past year has also been on understanding, designing and delivering low-carbon infrastructure through our Enterprise Model approach to integrated programme delivery. This is also aligned with our 40:20:20 vision for reducing carbon in infrastructure by 40%; reducing cost by 20%; and improving health and safety outcomes by 20% by 2025.

Our efforts in this area have been recognised in a recent report by the UK’s Construction Leadership Council (CLC) as an international best-practice example, highlighting our Enterprise Model as a climate-friendly approach to infrastructure delivery.

Supporting regional growth

There is considerable intensification occurring in our eastern and central-city catchments. The Tamaki Regeneration Company (TRC) and Kāinga Ora are increasing the number of homes significantly in the Tāmaki, Glen Innes and Panmure areas in the east, and Mt Roskill, Ōwairaka and Oranga more centrally. They are targeting at least a threefold increase in dwelling numbers while they maintain the existing social housing stock in the area and provide additional housing for rent and private sale.

We have been working with these two organisations, specifically in managing wastewater capacity, to mitigate any adverse effects of the redevelopment on our network and the environment. Since the wastewater flows from this area are highly influenced by wet weather, we are planning to replace old wastewater pipes that connect each house to our network as well as investigate potential improvements to the public water and wastewater networks.


Investing more to improve service levels

Our customers expect safe and reliable services every day. This means investing sufficiently so our water and wastewater networks can withstand disruptions and operate with minimal impact on our customers or the environment.

To build a resilient water and wastewater system, and ensure reliability of service, we will invest about $10.2 billion in renewing and upgrading critical assets over the next 20 years. This is a significantly higher investment in renewals than ever before and makes up almost half of the total investment allocated in our latest asset management plan.

This investment is also a reflection of the shift towards a proactive rather than reactive asset renewal strategy and will result in improved service levels. A proactive renewal strategy will lead to leakage reduction in the water network and infiltration reduction in the wastewater network, preserving water as well as network and treatment capacity for customers. An analysis of our operations by the Water Industry Commission of Scotland in 2020 concluded that proactive renewal of assets generally lead to lower operating costs and more efficient delivery of services in the long term. Find the detailed renewal programme in our latest asset management plan.