Drone revolution is flying high

G-MW manages about $5 billion in irrigation assets, including 10,000 kilometres of delivery and drainage infrastructure and 23 major water storages.

A crucial role of G-MW is to regularly survey these assets to ensure they are functioning as safely and efficiently as possible.

Surveying services manager Avni Bekirofski said it was a role G-MW was now performing more efficiently and comprehensively than ever before, largely thanks to drones.

“G-MW was quick to see drones as a useful tool to support its other surveying methods,” Avni said.

“In recent years, drones have become heavily integrated into our operations in various ways.”

A unique example of this has been G-MW’s use of underwater drones.

Much of G-MW’s critical infrastructure is underwater but still needs to be routinely inspected. In the past couple of years, G-MW has used underwater drones to conduct these inspections with increasing frequency.

Most recently, G-MW used a tethered underwater drone at Dartmouth Dam to inspect a winch cable that helps operate the dam’s low-level bulkhead.

Dam safety manager Sam Green said using drones for this task was far more efficient than the methods G-MW relied upon in the past.

“Dartmouth is one of our deepest storages, and the cable we needed to inspect was approximately 90 metres below the surface,” Sam said.

“In the past, we would have had to contract specially trained divers to complete an inspection like this.

“Using an underwater drone not only proved efficient but provided us with high-quality footage of the cable that can now be referred back to for future inspections.”

With drones becoming more widely used for surveying activities both above and below the waterline, G-MW has put added emphasis on upskilling its staff in the use of drones.

Recently, the water corporation has given particular focus to training its storage staff, who operate the lake, dams and reservoirs G-MW manages.

Over the past year, G-MW has trained and gained operator accreditation for about 40 of its storage staff.

Water storage services general manager Leonie Bourke said this training had been highly beneficial in helping staff undertake periodic inspections of the water corporation’s assets.

“For decades, the inspections conducted on our assets have been undertaken in-person, but drones now offer a valuable alternative,” she said.

This has been the case at Lake Eppalock, where storage staff undertake regular inspections of the lake’s embankment.

This used to involve someone walking the embankment and looking for any cracks, movement or changes.

Staff would walk across a narrow gravel track midway up the spillway, with the track being slightly hazardous in some areas.

These inspections are now completed by the same staff but using drones rather than walking the embankment themselves.

Leonie said there were various benefits to this.

“Not only is this safer and more efficient, but the data G-MW collects from these inspections is far more consistent,” she said.

“This better equips G-MW to detect any changes to the structure in the future.”

The authority is continuing to train more storage staff in the use of drones.

Storage staff have also been using drones to investigate compliance matters, such as monitoring ‘no boating zones’.

G-MW has also found innovative ways to use drones for more complex surveying activities.

LiDAR (Light Detection and Ranging) drones have been particularly useful in this regard.

LiDAR devices are incredibly precise. They work by sending out thousands of laser pulses each second. These pulses hit a surface and bounce back to the device. The device is then able to tell how far away a surface is by processing how long the pulse took to return.

In 2024, G-MW put this technology to use to survey Dartmouth Dam’s rock cascade spillway.

Dartmouth’s rock cascade spillway is vast, standing almost 200m tall.

Avni said surveying the structure had previously been an imposing task.

“Surveying Dartmouth’s rock cascade spillway has traditionally been labour-intensive, with a lot of manual set up required,” he said.

“Completing a survey like this with a LiDAR drone is a very different process and a far less time-consuming one. It also provides G-MW with more comprehensive data.”

During a pre-mapped, 30-minute flight over the spillway, the drone collects more than 400 million data points, which it uses to create a 3D model of the spillway, commonly referred to as a ‘digital twin’.

This model helps G-MW identify areas that may be in need of repair and also provides a useful reference point to compare future surveys to.

G-MW has undertaken similar surveys along large stretches of its channel network. In the past, the authority was only able to obtain such detailed data over such large areas by using a plane or helicopter that was fitted with a LiDAR camera.

LiDAR drones are a far cheaper way of completing these surveys and provide greater flexibility around when the survey is completed.

In the coming months, G-MW will increase its use of drones further, as its Electrical and Mechanical Services Team will start using drones with thermal imaging cameras to inspect node towers.

Electrical and mechanical services manager Craig Rowden anticipated this would be another area where G-MW benefited from the innovative usage of drones.

“When there is an electrical issue with a node, the area where the problem is generally emits heat,” he said.

“Thermal imaging is a very useful way to detect potential flaws and can often pinpoint issues that would otherwise take detailed inspections to identify, and we can now obtain this imaging using a drone equipped with a thermal camera.”

“This will reduce the need to have staff scaling the node towers to undertake the inspections, making it far safer and more efficient.”

G-MW will undertake several of these inspections as part of its 2025 Winter Works program.