Behind the scenes: How Sydney Desalination Plant stays running 365-days a year

Most of us don’t really know what happens at the Sydney Desalination Plant tucked away in Kurnell in southern Sydney, quietly keeping Sydney’s drinking water supply diversified and drought-proof, 365 days a year. We sat down with Kurt Galpin, Head of Asset Management, to find out what maintenance actually looks like at a facility that turns seawater into high quality drinking water, and why the work never really stops.

Maintenance is a year-round job

Kurt explained there isn’t a dramatically different maintenance routine depending on the time of year. “I don’t think there really is any change in approach depending on the season,” Kurt says.

The Plant runs on a rolling, methodical maintenance cycle, “it is sort of like painting the Sydney Harbour Bridge, you kind of go through, and once you get to the end, you go back to the start and off you go again.”

The Plant is broken into modules, two major ones split into 125-megalitre per day capacity sections, each containing reverse osmosis (RO) trains producing around 23 megalitres of water each per day. Maintenance teams work their way through, module by module, day in and day out, all year long, guided by an annual maintenance master plan that covers everything from condition assessments to individual work orders for replacements of parts.

Preventative versus reactive maintenance

If there’s one philosophy that defines how Sydney Desalination Plant approaches its upkeep, it’s to prevent problems before they happen, rather than reacting once something breaks.

“Our priority is to prevent assets from failing,” Kurt explains. “We want to maintain the assets or at least identify problems before they fail and before it becomes a reactive issue.”

Of course, sometimes the Plant requires reactive maintenance, but as Kurt says, “if our reactive maintenance starts to outpace our preventative maintenance, it means that we’re probably not doing enough preventative and everything is going reactive. There is also a balance of not doing too much preventative maintenance but also doing enough to prevent failures.”

In practice, that means consistent monitoring of the Plant’s core systems and ongoing asset condition assessments. In some cases, this could involve pulling RO membranes out periodically to be “autopsied” with their condition checked. Results are fed straight back into future planning.

Why winter is the time for bigger jobs

While the day-to-day preventative work never stops, Sydney Desalination Plant tends to schedule larger pieces of maintenance for the depths of winter when Sydney’s demand for drinking water is at its lowest.

“We do try to plan our preventative maintenance that requires Plant shutdowns to occur in the winter months,” Kurt explains. Things like the Plant’s 132 kilovolt switchyard, which requires annual compliance inspections, are scheduled during this period. “We generally have three or four shutdowns a year which are coordinated with Sydney Water to ensure there is no adverse effect on drinking water supply,” he notes, timed deliberately for months like the current one, well away from the drinking water high-demand summer stretch.

The impact of climate change

This consistent monitoring of the Plant has thrown up some interesting insights which Kurt’s team also incorporate into future planning.

The Plant’s seawater intake system was built with climate change in mind, designed to withstand sea level rise and storm surges. However, Kurt has noticed subtle shifts over time: “We have seen occasions where the seawater intake level is really low, which is unusual.” He also notes the Plant seems to be experiencing more frequent storms events that affect Botany Bay than in years prior.

These observations directly feed into long-term planning. “We take climate change risk into consideration when planning for the future at the Plant,” Kurt says. “As we’re more impacted by climate change, the need for drinking water from the Sydney Desalination Plant becomes more important. But it also means we’re exposed to more storm surges, wild weather, and potential bushfires.”

The Plant is well prepared for these changes, but it’s also one of the reasons why year-round vigilance matters so much. The Plant needs to be dependable precisely because the conditions around it are becoming less predictable.