Aotearoa New Zealand is known for its abundance of water, but the 2019/2020 drought that had serious consequences for Auckland’s water supply really focused attention on how we use this precious resource.
The 2019/20 drought kickstarted a conversation about the pressure that New Zealand’s water supply is facing as its cities and population grow. This has translated into a nationwide push to explore the supply, funding, and construction issues around water and, at the same time, preserve the environment.
This culminated in the Local Government (Water Services Preliminary Arrangements) Bill, which sits behind the Local Water Done Well policy. This gives New Zealand’s local authorities the ability to determine how they will manage their water supply, including stormwater and wastewater. The bill is expected to pass through parliament later this year.
A key challenge is how water is charged and valued, given that across much of the country (except Auckland), it’s included as part of council rates, not separately billed.
‘At the moment, many households don’t know how much water costs them and they don’t see the impact of things like leaks on the price of water,’ says KPMG Partner Mair Brooks.
This will change as the regulatory structure around New Zealand’s water system matures.
The role of technology
Technology is playing a significant role in understanding the state of the nation’s water infrastructure, including pipes, reservoirs and dams.
‘Digital tools are being used to develop an integrated water network map for the country. That will help us understand how water flows across the nation, where those assets are and what condition they are in, without having to dig up the pipes,’ says Brooks.
There are opportunities for New Zealand to apply best practice water management techniques from overseas to its water infrastructure. For example, engineering and consultancy firm WSP is exploring how New Zealand’s aquifers could be used to store water underground.
WSP’s Technical Principal in Hydrogeology, Eric Van Nieuwkerk, has been involved in similar projects in Australia and the Netherlands – experience he is now applying in New Zealand.
‘We are already extracting water from aquifers, which are naturally recharged from rainfall. But you can help that process by injecting more water into the aquifers in wintertime when there’s a lot of water available from high flows into the river and more rainfall. Then, in the summer when it’s dry you can use the water stored in the aquifers. It’s a way of banking water,’ says Van Nieuwkerk.
This is just one technique for better water management across New Zealand, with aquifers having certain advantages over strategies such as dam building. All the different techniques have their place, depending on local water requirements and catchment conditions.
For instance, injecting water into aquifers requires a much smaller footprint than a dam and there is no requirement to flood an above-ground catchment, or reduce the amount of land available for other purposes, such as farming, housing, and conservation.
Nevertheless, to be successful, managed aquifer recharge (MAR) requires a suitable aquifer system into which water can be injected and recovered when water demand is high. For example, if aquifers are too permeable, injected water might flow away quickly, reducing the effectiveness of a MAR strategy. It’s also important to manage the risk of clogging the injection and infiltration infrastructure with sediment and precipitates to maintain the system’s performance. It’s also vital to engage local iwi in any MAR project, so that any reservations about the mixing of waters are addressed at an early stage.
The nature of New Zealand’s topography also needs to be taken into account when it comes to water management.
‘We face significant risk of earthquakes and other natural events, so we need to really understand the resilience of our infrastructure. Technology can help with that,’ says Brooks.
Show me the money
Funding for New Zealand’s water system upgrades needs to come from a variety of sources, including government, the private sector and households. Alternative financing is also key, with an example being Wellington City Council’s recent use of the Infrastructure Funding and Financing Act 2020 to raise up to $400 million to build a sludge management facility at Moa Point.
Looking more broadly at regulation, New Zealand has an opportunity to draw on lessons from overseas markets, such as in Europe and Australia, around water health and safety standards, and market reforms.
‘What’s important is for everyone to have access to water in a fair, equitable and transparent way,’ Brooks says.
Managing supply and demand
Water servicing is about balancing supply and demand, not simply meeting whatever demand arises. Implementing strategies to make more efficient use of water is paramount to New Zealand’s future management of this resource.
Wellington is one area where there is significant work taking place on this. Currently, the capital has three main water sources: Te Awa Kairangi/Hutt River, the Waiwhetū Aquifer, and a grouping of rivers and streams in the Remutaka Range.
In summer, these sources can recede, and the ability to extract water from them is constrained by the low water levels and resource consent limits. This dynamic is affecting council water service providers across New Zealand. Experts such as Julian Fyfe, Water Infrastructure Manager (Central Region) at Awa Environmental, are working with councils to bring this issue to the fore.
This has come into particular focus now that it will be a key consideration in councils’ Water Service Delivery Plans, which are set to be mandated under the Local Government (Water Services Preliminary Arrangements) Bill.
‘We don’t have the luxury of giant storage reservoirs, such as the dams you find in countries such as Australia. So, we manage water year to year. If we have a particularly dry summer, we need to manage demand for water to protect the supply, and keep it safe and operable,’ says Fyfe.
At the moment, levers such as water restrictions are being used to limit how much water the population is using, especially in summer.
‘Water restrictions will need to be used more frequently as we wait for investment in new water sources and infrastructure to come online,’ says Fyfe. ‘But there is only so much behaviour change you can ask for from customers that see leaks running down the street. So, it helps to also be looking at helping customers change their water appliances and fixtures to more efficient options, among other demand management initiatives.’
Other strategies being used to manage demand include reducing how much water is wasted through leaks, investment in infrastructure such as water meters, and working with customers to help them become more water efficient. Raising customer awareness of the value of water and targeted pricing of water are also vital.
Looking ahead, while there are substantial changes coming to the way water is managed across the country, they are sure to benefit the nation and its inhabitants in the future.