A conversation with Roger Edgecombe
Roger Edgecombe may be a newcomer to Western Australia, but he's no newbie at RPS! This native Canadian has been involved in the growth of our energy development and seismic exploration business...
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There are a range of things you can do, but for me at RPS, my role with the Ocean Science and Technology team is more on the environmental side of coastal engineering. I do a lot of environmental modelling – so computer modelling of currents and waves in oceans, harbours, inlets and looking at the dispersion of substances within these systems.
And that is used for, say, oil spill modelling for the oil and gas industry or modelling suspended sediment plumes generated from dredging projects. And we’ve recently been doing a bit of work for the offshore wind industry where we’re modelling waves and currents around the monopiles – or the foundations of the wind turbines.
The team I work with also use environmental modelling to support 24/7 maritime response services for disasters such as oil spills, and work with the Australian and New Zealand water police for search and rescue operations.
Then there are also different roles for coastal engineers that focus on coastal erosion/protection and the design of coastal structures such as breakwaters, but that’s more on the engineering side.
Senior Coastal Engineer based in Perth, Western Australia
Coastal engineering and modelling for a wide range of coastal and offshore development projects, marine search and rescue and more.
I love the ocean. Back in high school I thought about doing marine biology or marine science. I ended up doing environmental engineering at university – my strong subjects at school were math and science so I went into engineering and the environmental engineering side of it appealed to me most.
Not a lot! There is some field work depending on your role – inspecting beaches if you’re doing coastal erosion work or conducting field measurements of metocean conditions – which are atmospheric and oceanic parameters, like wind, wave, current, climate. But mostly, I am sitting behind the computer. Although in my spare time I spend as much time in the ocean as I can sailing, paddle boarding, surfing, snorkelling, or just splashing around with my kids.
The Elizabeth Quay project. It involved a redevelopment of the foreshore in Perth and construction of a new inlet.
There were a few concerns about creating an inlet. The big one was water circulation or flushing times – how long the water would stay in the inlet. If the water stays too long there can be a build-up of nutrients that lead to algal blooms that would then go out of the inlet and affect the Swan River estuary. The project also required some dredging works to be done, so we had to look at whether any of the suspended sediment from the dredging would affect seagrasses or marine life in the area.
To ensure adequate circulation between the inlet and the surrounding water, we looked at different design layouts of the inlet and came up with some solutions like having two entrances to help circulate water more efficiently.
To understand the impacts and inform the inlet design, we modelled the whole Swan River estuary, including tide, wind and temperature and salinity driven flows - the dynamics of the salt wedge of the incoming ocean waters are important to circulation and water quality in the river.
We looked at the circulation in all seasons, and our water team did a range of field measurements, like salinity and temperature and nutrient levels to validate the model. It was a great project to work on – interesting, challenging – and a feature in the heart of Perth.
There can be. It’s interesting to look at different scenarios and see how sensitive the system is to changes in designs and how that might alter the impact on the environment. For example, do 300 smaller structures, like wind turbines, have a greater impact than 100 larger ones?
We constantly test our assumptions and where we can we use field measurements over long periods of time to validate our models so we can be as accurate as possible. We also use statistics to indicate the accuracy of the model.
It drives me to create a model that is as close to reality as possible – so it shows the real effect of any changes proposed. I think that has impact – and in doing that I’m helping to protect our waters and our coastlines. Obviously, development must happen, but you can mitigate damage and optimise designs to have the lowest impact with this type of information at hand.
I like the variety of the work. I feel like I’m always learning and developing my skills by working on the wide range of projects that we are involved in. And now with a new industry developing in offshore wind in Australia we have more to learn – it is challenging, but interesting too!
I have been working on wave and hydrodynamic modelling for the Star of the South offshore wind project in Victoria, I’m also working on sediment dispersion modelling for a port expansion project in WA, and for the Barossa project in Darwin Harbour. I have also recently been involved in hydrodynamic modelling for desalinisation plant discharges for a mine site in the Pilbara region of WA.