Improving Asset Maintenance with Aerial Data

In addition to site analysis and inspection, Sydney Water’s Spatial Hub can perform tasks such as tracing upstream of sewers, modelling flood risk and simulating outages. This increased situational awareness helps improve asset maintenance and results in better customer outcomes.

“We use our own records [and] we use data from all sorts of disparate sources — but having the Nearmap product in there gives us a real powerful source to see,” said Dino Scotter.

As part of its wider asset maintenance network, Sydney Water monitors approximately 10,000 level-switches located in sewer-access points. These sensor-driven switches trigger an alarm if certain thresholds are exceeded. Spot-readings from the sensors provide valuable real-time information. “This is IoT [Internet of Things] technology now,” said Dino Scotter.

Dino explained that overflows in the Sydney Water network can result in financial penalties from the NSW Environment Protection Authority (EPA). With thousands of kilometres of sewers to maintain, real-time information from sensors helps Sydney Water prioritise preventative maintenance programs and repairs.

Just as Dino was telling us this, an IoT sensor alert flashed on his screen in Spatial Hub indicating a potential fault or maintenance issue needing attention. Dino showed us in real-time how the Sydney Water team uses Nearmap imagery within Spatial Hub to help manage such occurrences.

As soon as a sensor alarm alert is received, Dino can identify the location on a basemap.

Once the location had been determined, Dino activated the property boundaries data layer in the Sydney Water Spatial Hub, to get a better idea of the sensor's location in relation to surrounding properties and roads.

Activating the property boundaries provided a general overview, but Dino needed more situational awareness to start planning the next steps. He activated the Nearmap layer and it became clear that the sewer access point was at the rear of a residential property, in a location surrounded by fences, with only one narrow access route in and out, surrounded by large trees and vegetation. All that intelligence from one image.

That was important information, as it helped Dino understand that fixing the issue might be more complicated than it first appeared. Using Nearmap imagery, Dino could measure access to the site, and calculate whether the surrounding vegetation would cause access issues for equipment and vehicles. This information could be entered into the work package to share with Sydney Water maintenance crews, potentially avoiding unnecessary repeat visits that would otherwise inconvenience the property owners.

Dino Scotter explained that the sewer line’s patterned marking meant it had a special condition: that it was in a tunnel. “The reason it would be in a tunnel would be because there's some kind of structure over it — there might be a swimming pool, a built structure, something like that,” said Dino.

As soon as Dino zoomed-in to look closer at the Nearmap imagery, the details popped, in high-resolution: a swimming pool and surrounding structures, just as he’d anticipated.

The clarity of the Nearmap imagery also revealed that there was a stormwater drain in the property’s driveway, located approximately 30 metres from the sewer access point. (Even if council stormwater data was missing from Spatial Hub, high-resolution Nearmap imagery can help Sydney Water spot any stormwater assets in the surrounding area.)

Using tools in Sydney Water’s Spatial Hub, Dino could calculate that the stormwater drain was at an elevation of 17cm higher than the sewer access point. This reassured him, as it indicated that if an overflow were to occur at the sewer site, it wouldn’t be likely to reach the stormwater drain, preventing potential stormwater contamination: another vital piece of geospatial intelligence. Dino could even measure the clearance between the top of the trees along the driveway and the edge of the building.

The Sydney Water Spatial Hub includes imagery layers from other aerial imagery providers, however that imagery can often be out of date and less-clear (Nearmap high-resolution imagery offers a Ground Sample Distance (GSD) of 5.6–7.5cm).

“Having that level of information before you actually do that first site visit is really important,” said Dino Scotter. “I could probably get this at least three zoom steps further in with Nearmap than I can get with any of the other products. It’s just so revealing – it’s like being on site, really. It takes it to another level.”

Comparing Nearmap imagery to imagery from other providers showed the advantages of high-resolution clarity, and recency — the sharper and newer the image, the better.

Another benefit of high-resolution aerial imagery to Sydney Water is the ability to see when construction work starts on a previously vacant site. From the time a development proposal is submitted to the time construction begins, there can be significant delays, sometimes decades-long.

With an up-to-date view of sites showing construction,Nearmap imagery can show construction and new structures.

Remote site visits can help Sydney Water work toward its target to reach net zero carbon emissions by 2030.