Case study

Gippsland Water

Assets condition assessment

National Drones has been working with Gippsland Water to explore ways in which maintenance inspection times can be reduced and greater insights can be gained into major asset condition via remote aerial image survey, thermal imaging and Normalized Difference Vegetation Index (NDVI) analysis.

Gippsland Water delivers reliable, high-quality water, wastewater and waste recovery services to ensure social, environmental and economic benefits to domestic and commercial clients across Central Gippsland, Victoria, servicing more than 65,000 customers across over 5,000 square kilometres.


Gippsland Water manages and maintains a Regional Outfall Sewer (ROS) that carries industrial wastewater to a series of treatment plants before being released to the environment via outfall pipes.

With a total length of 85.6 kilometres, the ROS is a combination of open channel (40.6km), and below ground pipeline (45km).

The ROS is currently inspected on foot or by vehicle to assess condition and identify areas requiring maintenance or urgent attention.

Inspections are carried out as part of routine field operations on average once per month requiring significant field resources and time.

A 2.5 kilometre trial site was selected by Gippsland Water to conduct a Remotely Piloted Aircraft Systems (RPAS) image survey. Due to the close proximity of the trial site to the East Sale Air Force Base, National Drones liaised closely with the base to secure flight permission and ensure that all operations were conducted safely within the surrounding restricted military airspace


  1. Aerial photogrammetry survey – High resolution aerial image capture of the ROS trial site. A UAV is quick and cost-effective method for capturing high quality survey / image data.
  2. Desktop assessment – The captured aerial survey imagery is post processed to create a high resolution georeferenced map of the survey site. An assessment of the imagery was conducted to identify and locate: a. Ground assets associated with the ROS b. Asset condition such as bank erosion and potential channel blockages or obstructions c. Areas of potential ground water leakage for field investigation
  3. Online inspection and reporting tools – Results can be quickly shared with field staff online or by report generation pinpointing the exact assets and locations where further investigation is required.


The trial was conducted over a 2.5km section of the ROS channel covering an area of approximately 23ha.

The survey was completed in approximately 2.5 hours by two operators (RPAS Pilot and an aerial spotter) including pre-flight site assessment, safety briefing and equipment setup.

Some 700 high resolution images of the site were captured for later processing and analysis.

The trial allowed Gippsland Water to quickly review and assess the overall condition ROS trial site.

As well as being able to quickly locate, identify and assess the condition of nemerous ground assets associated with the ROS channel, two maintenance issues were identified shown in Figure 3. The aerial imagery provided a unique perspective of the asset with the ability to identify and assess features not normally as easily identifiable at ground level


The potential benefits for Gippsland Water include:

Reduced field operations time required for asset inspections from days to hours via desktop assessment

Optimised allocation of field operation resources for proactive issue investigation and resolution, instead of time-consuming data collection and reactive work Early detection and resolution of maintenance issues leading to time and cost savings

More efficient work / maintenance planning through change over time monitoring.

Improved asset register quality, both in terms of completeness, with newly found and verified assets, as well as accuracy, through high resolution imagery and geo-location precision Enhanced online data availability for stakeholders.

Whilst not part of the trial, with the addition of Ground Control Points (GCP) other survey, mapping and terrain features can be easily determined from the image data such as elevation, slope and contour mapping.

National Drones are also working with Gippsland Water to trial detection of issues (such as underground water leakage) using thermal imaging and Normalized Difference Vegetation Index (NDVI) monitoring

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