Protected and enhanced natural environment, leading-edge resource efficiency and reuse of resources including water.
As a water and wastewater services provider for 1.7 million Aucklanders, our work is extremely dependent on the natural environment and, at the same time, has an enormous impact on it.
Extreme weather influenced our operations significantly during 2019/20. We began the year with prolonged dry weather and water storage levels lower than normal. While delayed rainfall in spring 2019 increased the storage levels over September and October, the dry weather resumed in November.
Since then, Auckland has been in a severe drought, with our water storage lakes receiving almost 40% less rainfall between November 2019 and May 2020. These storage lakes typically supply two-thirds of Auckland’s water demand so the rainfall deficit is very critical to the region.
In 2019/20 we also observed an overall increase in demand for our water, especially record-breaking daily consumption during February due to hot and dry conditions.
Our efforts throughout the year have been focused on ensuring security of supply to our customers and the wider community. We introduced new tanker filling stations to help those on tank supply over summer. We maximised water production from sources that are independent from our supply lakes, such as the Waikato River and the Onehunga aquifer. We did this to preserve the water in our supply lakes and enable them to recharge. We also focused on augmenting our water supply with an investment of $224 million and managing demand.
In May 2020, when the water storage levels in the lakes fell below 50% for the first time in 25 years, we recommended the implementation of Stage 1 Water restrictions as part of the Auckland Metropolitan Drought Management Plan in conjunction with Auckland Council.
Apart from upgrading and maximising production at Waikato and Onehunga water treatment plants, we are also working to return two former water sources – Hays Creek Dam in Papakura and a bore in Pukekohe – which will provide an additional capacity of 40 MLD by December 2020. Planning, consenting and construction on these four projects are progressing at pace. These projects will not only provide additional water next summer, but they will also help to speed up the recovery in storage levels for next winter.
We have invested significant resources towards reducing the amount of water lost through leaks and breaks in our water pipes. Annually, about 13% of the total water we produce is lost through leaks. While leaks are unavoidable for all water networks around the world, we know there is more we can do to reduce this volume. We therefore have a programme of works completed and underway that includes proactive leak detection across our 9000 kilometres of water network, prioritised management of leaks and pipe renewals.
In line with the Drought Management Plan, throughout the year, we urged Aucklanders to be water-efficient and make voluntary savings. When the lake levels dropped critically in May, Auckland Council imposed stage 1 water restrictions which prohibited the use of outdoor water hoses and water blasters for residential water users; Auckland Council, commercial and other non-domestic water users cannot use potable water to operate a car wash, water sports fields, plants or paddocks.
We did not recommend these restrictions lightly. We understood they would have a bigger impact on commercial water users than on residential water users and we knew it came at a very difficult time for businesses, given the challenges of COVID-19. However, permitting drinking water to be used for outdoor and non-potable uses when the region continues to experience the worst drought on record is not sustainable.
We are working with Auckland Council to support impacted businesses by providing millions of litres of non-potable water from various sites across Auckland. Proving that necessity is the mother of invention, a number of Auckland businesses have overcome the impact of these restrictions by accessing water from these and other private bores and reusing water in their processes and operations.
Our own Central Interceptor Wastewater Tunnel project has been using non-potable water at all of its construction sites. The project will be using recycled wastewater from the Mangere Wastewater Treatment Plant to clean and operate a tunnel-boring machine.
These are encouraging shifts in thinking and behaviour that recognise the value of water, especially high-quality drinking water that Aucklanders have reliably enjoyed, without any restrictions, over the past 25 years.
While the drought dominated our work and resource allocation during the year, we made significant progress in some of our ongoing projects: we planted another 303,000 seedlings in the Hūnua Ranges, as part of our progressive regeneration of a former pine forest with native trees and plants over the next 30 years.
We partnered with Vector PowerSmart to install New Zealand’s first-ever floating solar array on the oxidation pond at our Rosedale Wastewater Treatment Plant. This floating array is made up of 2700 solar panels and 3000 floating pontoons and the installation is expected to be complete in September 2020. It is the largest solar project in the country and will generate enough energy to power 200 homes for a year. It will increase the energy self-sufficiency of the Rosedale plant and is part of our energy efficiency and neutrality programme.
We also expanded our fleet of electric vehicles from five to 30 during the year, effectively removing 45 tonnes of carbon dioxide from the environment.
All of these initiatives are part of our ongoing organisational commitment to reduce the impacts from climate change.
Watercare’s proactive leak detection programme has prevented millions of litres of water loss at a crucial time for Auckland’s water supply.
The programme – which finds invisible leaks by listening for distinctive leak sounds – was accelerated this year as the region suffered the worst drought on record.
The programme has focused on areas in Auckland with the most reported leaks, including Mt Wellington, Ellerslie, New Lynn, Māngere, Ponsonby and Herne Bay, and covered more than 1140 kilometres of pipes.
Acoustic leak detection involves listening for signs of a leak by tapping a stick microphone to a meter or pipe connection. Leaks have a distinctive sound as they are constantly running. The checks are repeated at different times of the day to confirm it is a leak. The volume of the leak is estimated based on the sound detected.
From the work completed so far, an estimated water loss of more than two million litres a day (MLD) has been prevented.
Acoustic leak detection work is just one element of a wider programme to minimise water lost to leaks.
We spend more than $20 million a year replacing ageing water pipes and their supporting infrastructure and we are looking at increasing investment on renewals. We have also put more crews in the field so we can investigate and fix reported leaks as soon as possible. We aim to repair urgent leaks within a few hours, and all leaks within five days, but sometimes, due to the location of the leak and factors like traffic management, they do take longer.
While every effort is being made to reduce leakage in Auckland, leaks are expected in all water networks around the world. They can be caused by many factors: hot, dry weather and ground retraction; vibrations including heavy traffic; and damage caused by a third party working in the ground.
Auckland actually has one of the better leakage rates in New Zealand. However, we know there’s room for improvement so, by July next year, we expect to have proactively checked more than 6000 kilometres – almost two-thirds – of Auckland’s water pipes.