Growth on this scale is significant, and requires us to ensure we have a clear understanding of where and when investment in planning and infrastructure will be made.
Over the next 10 years, we plan to invest $5.5 billion in water and wastewater infrastructure for Auckland. Forty-eight per cent of this investment will be directed to increase capacity to support future growth, 38% will go towards renewing and replacing existing assets and 14% towards improving the level of service for our customers.
To help us prepare for this level of growth, a number of projects were completed in the last 12 months that will enable us to maintain or improve service and cater for growth in Auckland.
We awarded the contract for construction of the Central Interceptor wastewater tunnel. The Central Interceptor will run for 13 kilometres from Western Springs to a new pump station at the Māngere Wastewater Treatment Plant. At 4.5 metres in diameter, it will be Auckland’s largest wastewater tunnel and the biggest wastewater project ever undertaken in New Zealand. This project will improve the health of our city’s waterways by reducing wet-weather overflows and provide for population growth.
We progressed work on replacing a wastewater pump station and building a wastewater storage and conveyance pipe in Glen Innes that will improve the area’s waterways and cater for intensification in the east-Auckland suburb. The new pipe and pump station are expected to be operational in 2020.
We successfully completed upgrades to the Army Bay Wastewater Treatment Plant in the Whangaparāoa Peninsula which means the plant will continue to treat wastewater to a very high standard and can manage growth from across Orewa, Silverdale and Whangaparāoa.
We began the upgrades to the Pukekohe Wastewater Treatment Plant. This plant treats wastewater from Pukekohe, Buckland, Tuakau, Pokeno and Patumahoe and these upgrades will cater for future growth in this fast-expanding region. They will also reduce wet-weather overflows and improve the quality of water discharged into the local Parker Lane stream and the Waikato River.
On the water side, we submitted a resource consent application to Auckland Council for replacing an ageing water treatment plant and building two storage reservoirs in Waima, West Auckland.
The existing Huia Water Treatment Plant was built in 1928 and supplies up to 20% of Auckland’s water needs. It is reaching the end of its operational life. The proposed treatment plant will replace it and the reservoirs will increase the volume of water stored locally, improving the resilience of the wider water network and accommodating daily demand fluctuations.
We began construction of a reservoir at Pukekohe East. It will store up to 50 million litres of water and will increase security of supply and provide greater resilience for Auckland.
We began laying the last section of our 31 kilometre Hūnua 4 watermain mainly through tunnelling, to avoid disruption to communities and businesses in the area. This will carry treated water from our Redoubt Road Reservoirs to our Khyber Reservoirs, ensuring security of supply to communities across Auckland.
While we continue to think and plan ahead, we are also challenging and improving the way we deliver infrastructure. We are one of the few companies in New Zealand that have a confirmed infrastructure programme for 10 years and we want to leverage the scale and scope of this programme to deliver more sustainable infrastructure in a safe and efficient way.
To this end, we are moving in a bold, new direction with an ambitious 40:20:20 target to achieve wins in sustainability, safety and costs. The 40:20:20 objectives are to reduce carbon in construction, or ‘build carbon’, by 40% across Watercare by 2024; to reduce the cost to deliver our infrastructure programme by 20% by 2024 and to improve health, safety and wellness by 20% year on year.
Our approach will include a focus on standard product designs, budgeting for carbon emissions, reviewing supply and build elements of infrastructure and reimagining the way we engage. This will require new thinking and challenging the way we work to find safer, more sustainable and efficient solutions.
We will move to an integrated programme for delivering infrastructure. The way we work now is to find contractors to do work on a project-by-project basis. But the way for the future is to partner with two construction companies and our designers to deliver our programme of works. This will facilitate cost efficiencies, standardisation and innovation.
It means working with fewer contractors, getting them involved far earlier and working together much more closely to deliver our 40:20:20 targets. We have gone to the market with a request for proposal to partner with us and will finalise the companies by the end of 2019.
The Army Bay Wastewater Treatment Plant is our third- largest wastewater treatment plant and currently services the Hibiscus Coast and Orewa area, which has a population of around 46,000 now and is projected to increase to a population of 188,500 by 2053.
One of the projects we successfully commissioned this year is the $31-million upgrade to the plant that included improvements to an existing pump station, and replacement of an outfall pipe, which extends 1.2 kilometres into the Tiri Channel. These improvements mean the plant will continue to treat wastewater to a very high standard and can manage the growth from across Orewa, Silverdale and Whangaparāoa.
The location of the construction works was within a sensitive ecological environment, adjacent to Shakespear Regional Park and significant care was taken to isolate construction sites and protect local wildlife, including kiwi and lizards.
The outfall pipe was laid using the direct pipe method of micro-tunnelling, which was a first for New Zealand. A section of the pipe, about 900 metres long, was assembled in Kaiaua, towed along the coast and floated into place on the seabed. The project was delivered on time and within budget – a successful outcome, especially given the complex nature of the micro- tunnelling and the installation of the outfall pipe.
The project was recognised for excellence at the Auckland Civil Contractors New Zealand (CCNZ) Awards 2019 and is a finalist entry at the CCNZ National Excellence Awards 2019.