Summer Water Security

Summer is in full swing and that often means the Sydney Desalination Plant (SDP) is called upon to support Sydney Water in supplying high quality drinking water to the Sydney. What many people don’t realise, is that the Plant is on and operational year-round.

However, increased risk of droughts and extreme weather with climate change putting more pressure on the system during the summer months means the Plant is always prepared.

To kick off 2026, we sat down with SDP’s CEO, Phil Narezzi to discuss how the Plant is supporting Sydney’s water security this summer.

1. For readers who may not be familiar, what role does the Sydney Desalination Plant play in Sydney’s overall water supply system?

“The Plant was originally designed as a drought response measure – providing an emergency valve for the city’s drinking water supply. What most people don’t realise, because SDP supplies water to Sydney Water rather than directly to households, is that now we are on and operational all the time. Since 2019, SDP has operated at around 100 million litres per day on average (equal to 40 Olympic swimming pool per day), providing a steady, rainfall‑independent source of drinking water whilst being ready to ramp up quickly to support the water system in times of need.

“The Plant’s quiet, consistent contribution plays a significant role in keeping taps flowing reliably across Sydney.”

2. Why is having a rainfall‑independent water source so important for a city like Sydney, especially as our climate becomes hotter and drier?

“Sydney’s climate is becoming hotter and drier, with more intense heatwaves and longer dry spells between rain events. Our traditional water sources depend entirely on rainfall, which is becoming less predictable.

“The Plant diversifies Sydney’s drinking water supply. It doesn’t matter if it hasn’t rained for weeks, SDP can still produce high‑quality drinking water from seawater anytime, on-demand. This is important, especially during the summer months, because demand spikes when it’s hottest. On scorching days, people use more water for drinking, showers, swimming pools and gardens. Water security comes from diversity. Relying on one type of water source is risky, so adding SDP’s rainfall‑independent supply makes the whole system more resilient.”

“Desalination doesn’t replace dams, but it does take the pressure off them, especially when we need it most.”

3. How does SDP specifically support Sydney during heatwaves and extended dry spells, when demand for water tends to spike?

“Although SDP operates to an annual water order issued by Sydney Water, it’s designed to be flexible. For example, when a heatwave or extended dry spell is forecasted, we are already monitoring the potential impacts. We continuously monitor medium‑to long‑term weather forecasts, tracking dam levels and broader system conditions to ensure we are ready to respond if Sydney Water needs to increase supply.”

4. Can you talk about what happens operationally at the plant when a heatwave is forecast? Do you ramp up production in advance?

“Operationally, the Plant can substantially increase production in a short period of time. That responsiveness means we can support the system not just during declared droughts, but during any period of high demand or emerging stress on the system.

“For example, Sydney Water has recently been asking how ready the Plant is to support periods of hot weather and the potential next drought cycle. As climate change reshapes our weather patterns, SDP’s job is not just to respond in the moment, but to stay prepared over the long term.”

5. What climate projections or trends are you planning for when it comes to future heatwaves and dry spells?

“Our preparation includes constant monitoring of forecasts and dam levels so the Plant can anticipate when it may need to ramp up production. We tend to maximise opportunities to schedule maintenance in low flow times, when the broader system is under less pressure, so the Plant is readily available when conditions tighten and we are most needed.”

6. How do you balance the need to be “on standby” for droughts with the cost of running a large piece of infrastructure?

“We have to strike a careful balance between being on standby and managing costs and this balance is regulated by the Independent Pricing and Regulatory Tribunal (IPART), which sets the framework for how SDP operates and the maximum prices we can charge for the drinking water we produce.

“The pricing structure is designed to ensure the Plant is ready when needed and provides a prudent service to customers at an efficient price.

“Over the years, SDP has refined how it operates, becoming more effective and efficient at providing a water security role. We are currently preparing our regulatory proposal to IPART that will be submitted in September 2026.”

7. How do you communicate to the community the value of desalination, given that some people only notice it when there’s a drought?

“Most people don’t notice that the Plant is operating, we are just part of the drinking water supply for Sydney. That reflects the valuable role we play in Sydney’s water system. It’s not just as an emergency measure, but as an ongoing insurance policy for a growing, climate‑exposed city.”

8. What do you wish more Sydneysiders understood about the role desalination plays in protecting them during extreme weather events?

“SDP exclusively supplies Sydney Water, so households and businesses don’t receive a separate “desalination bill,” and there’s no tap that says, “dam water” versus “desalination water” – it’s all blended into the same network, it is effectively the same high quality drinking water.

“So, because the dams have been mostly full in recent years, many people assume the Plant is idle. In reality, the Plant’s been operating continuously in the background since 2019, strengthening the system resilience and ensuring Sydney is better protected when issues arise and climate conditions turn.”

9. If you had to sum up SDP’s contribution during a major heatwave in a single message to the public, what would it be?

“We are continuously operating, always ready to increase production ensuring Sydney has enough high quality drinking water even when the weather is at its most extreme.

“The next time the temperature soars and the city leans heavily on its water supply, part of what’s keeping your tap running will be a piece of infrastructure, quietly turning seawater into high quality drinking water.”