Understanding the path of stormwater

Joycelyn Siew, Senior Hydrologist

Joycelyn Siew, RPS Senior Hydrologist, Perth, Western Australia

With almost a decade of experience as a hydrologist – managing surface water and shallow groundwater - Joycelyn says she’s drawn to the problem-solving nature of her work and how it makes real-world impacts in communities. 

QWhat’s the role of a hydrologist on the projects you work on?

A lot of my work is for residential developments, so housing estates. My primary role is to consider how to best manage stormwater at the site. In other words, when it rains, I need to know where that water will flow and how much – and that’s the fun part.  

I create models of different scenarios to see what will happen. I work closely with the engineers and landscape architects to try to incorporate water management features – like biofiltration basins, living streams, or rain gardens - into the design. 

It’s about balancing all the different design requirements while still providing enough space to hold all the stormwater.

Meet Joycelyn

Role at RPS

Senior Hydrologist based in Perth, Western Australia

Specialising in

Water solutions for development, mining and other projects, with a specific focus on stormwater management.

QWhat does a typical day look like and what do you like best about your job?

I do a lot of stormwater modelling. It’s the really technical part of my work and it’s the best part. I love detail and solving problems. I like having to balance all the different requirements and view a project from a range of perspectives.  

From my perspective, I’m looking at the subdivision layout, the contour of the land, the water table, soil type, surrounding environments (like wetlands). Then I need to consider, ‘Okay, is the drainage I’m proposing actually feasible for the engineers to build? What is the landscape architect going to want and need?’ What does the client want? What are the requirements for public open spaces – how much can be for amenities, how much for drainage?  

There are a lot of things to juggle. But the real prize is when you can answer all those questions and enhance the space – that’s satisfying. 

QAt what stage of a development are you involved?

My role is involved through the entire planning process. So, for a residential development or estate, I’ll work on a site through the rezoning, the structure planning and then all the way through to when they actually subdivide the site and start building the homes.  

There are several approval processes to turn land into a new housing estate and at each stage of the planning process (for example, at a district, local or subdivision scale), we’ll prepare some form of water management document.

QWhat’s it like to see a finished development?

We sometimes do water monitoring when a development is finished and it’s fulfilling to see it all come together. After you've been buried in numbers and engineering drawings – where everything is flat and on paper - then to see it actually built is great. I also like seeing how the landscape architects’ work has turned all the functional aspects of the project into something beautiful – into a place where I’d like to live. 

QHow big are the housing developments you’re working on?

The smaller ones start from 100 lots right up to one of the big developments I'm working on, which essentially spans two whole suburbs – about 4000 lots. It's huge and one of those developments that will take something like 20-30 years to complete. 

I love detail and solving problems. I like having to balance all the different requirements and view a project from a range of perspectives...the real prize is when you can answer all those questions and enhance the space – that’s satisfying.

Joycelyn Siew

Senior Hydrologist

QAside from residential developments, what are some other projects you’ve worked on?

We sometimes work on commercial developments instead of residential. I have also been involved in projects for water corporation and mining clients before. They tend to be more flood studies and flood management.  

What's going to happen in a 100-year event? How big do the culverts under the road have to be? How high do you need to build a bund to protect the infrastructure? When is it safe to discharge water to a creek without causing flooding? Those types of things.  

QWhat did you want to be when you were growing up?

It's changed over the years, but at one point I wanted to be a vet. And when I was going into university, what I wanted to be was a conservation biologist.

QSo how did you end up working as a hydrologist?

I was going to study a biology-related degree, but then I thought – you know what, I have all the prerequisites to do engineering – two maths, three science subjects in high school. Why not? Let's just do a double degree. And the only science-engineering combination at my university that focused more on the biological sciences was zoology and environmental engineering. So, I did that! 

The environmental engineering course at my university had a strong focus on water. My thesis project involved monitoring and assessing surface water flows, groundwater levels, and water quality. This thesis work led straight into my first professional job, and I’ve worked in this space ever since.   

More ideas and insights from our local team

Discover more from our team or get in touch with Joycelyn for support with your next project. 


Boats moored off the beach at sunset, Rottnest Island, Western Australia

Get in touch

Your contact information:

All fields are mandatory *

Get in touch

Your contact information:

All fields are mandatory *