The City of Greater Geelong (COGG) is Victoria’s largest provincial city and includes urban, rural and coastal areas. It’s home to over 250,000 people who rely on $600m worth of stormwater assets below ground to work as they should.
But what exactly that infrastructure looked like was unknown back in 2018 so COGG asked Morphum Environmental to investigate.
The Challenge
It’s quite common for Victorian councils to not have a complete picture of their stormwater networks – as a state typically affected more by drought than floods, stormwater assets have not always been a high priority.
With a growing focus on water quality treatment, stormwater harvesting, sustainable growth, and climate change, COGG wanted to look for a more strategic and proactive way to managing the city’s stormwater.
The Approach
When investigating a city’s stormwater assets, Morphum uses a three-stage process to understanding a network as quickly as possible:
Drainage data discovery (health check). This first step will gain an understanding to the location and attributes of underground assets including pits, pipes and waterways and how they are connected to one another.
Connected Network. Provides the building blocks to identify and prioritise the spatial and attribute data gaps in the drainage network.
Advance Asset Management. With a fully connected network, overland flowpaths can be combined in to create a single, traceable geometric network with directionality functions to allow for advanced asset management including WSUD asset prioritisation, contaminant load modelling, risk assessments and more.
The first stage on this journey was to gain a comprehensive understanding of what stormwater assets they had recorded and the accuracy of that data, but equally looking at where data gaps were.
The more you know about your current network, the more you can plan for future changes that will be required such as integrated water management (IWM).
COGG shared their stormwater drainage data to Morphum whose team of GIS specialists and engineers carried out a health check analysis of the city’s stormwater network (Drainage Data Discovery). This combination of skills provides a rare balance of understanding the lines and points on a map but also how stormwater networks function in the real world, enabling Morphum to provide genuine insight and practical recommendations.
Over a two-week period Morphum discovered COGG had a good spatial understanding of where their assets were located. But their knowledge of their assets’ attributes - how big pipes were, how deep, what material they were made of - was lacking. Again, this is a very common scenario.
This missing information is crucial when managing a stormwater network. Repairs and maintenance are more cost-effective if you plan ahead and know when areas of the network will need attention. Replacing pipes can also be combined with major roading projects to keep overall costs down.
Knowing the exact size of underground pipes and how they connect together is also vital when planning for future growth. COGG officials need to accurately assess if there’s enough capacity in the stormwater network when looking at proposed developments.
The Result
Following the health check, Morphum was able to generate an interactive map of COGG’s stormwater drainage network. By clicking on any point on the network map and tracing downstream, COGG can now see where the water is going to flow down to Port Phillip Bay or into a river and if existing pipes are big enough to handle it.
More informed decisions can also be made around water treatment options, such as water sensitive urban design (WSUD), as there is now greater visibility about what contaminants might be travelling downstream through the pipe network towards the region’s waterways.
But none of this would be possible without having first undertaken the Drainage Data Discovery project. It’s a key starting point, allowing Morphum to recommend the next steps on how COGG could move forward to better manage their stormwater assets and plan for the future.