Standing on the edge of the 'Infrastructure Cliff'

It’s a known fact that parts of the critical infrastructure built by our parents and grandparents and even great grandparents are reaching the end of their useful lives and some high profile cases have prematurely failed with spectacular consequences.

The water sector is not immune from these inconvenient facts especially when it comes to underground critical infrastructure such as water and waste water pipes. This critical infrastructure is the backbone to modern society however it is widely reported that even today, around 750 million people around the world do not have daily access to clean, reliable and safe drinking water.

Over the past 20 to 30 years there have been significant breakthroughs in the technology and solutions to rehabilitate our waste water network, this is not the same for water mains. Potable and raw water mains failure mechanisms are very different to gravity sewer and therefore the rehabilitation methods are very different and more limited in options and can be very costly and highly disruptive.

Equally challenging is condition assessment for pressure mains which is very different to that for gravity mains and can involve investment that is hard to justify.

In 2018-19 Rob Fearon and Ryan Cosgrove from qldwater set out to investigate how many water and sewerage mains there are in Queensland and what their age profile reveals about risk of failure. In 2019 the second of two papers on the “Infrastructure Cliff” was released. As a follow up, I asked Rob and Ryan a series of questions from the paper and how the work was received.

What surprised you with the data collected throughout Queensland?

There were a number of surprises. While the types and sizes of pipes mostly fit into standard categories, there was a huge diversity of diameters and materials across Queensland. This hinted at the range of suppliers that were used by councils over the years – and the oldest pipes recorded as still in use were easily over 100 years old.

A surprise from the second report was the range of unit costs for renewals. Factors like density of urban design, traffic control and other externalities really increased the cost of full renewal making relining an important alternative where it was viable.

How long did it take to collect the data?

Many councils and utilities shared their data very rapidly, but collecting a set that represented the whole state took over six months and there were still gaps, particularly in condition and criticality assessment and installation dates. So, the accuracy in terms of the materials, sizes and ages of pipes out there is great, but we would like to know more about how much is installed or rehabilitated on an annual basis.

Has your work been shared outside Queensland or Australia?

There are two papers and four fact sheets published on the web and which were reviewed extensively by the water sector and Queensland Government. We have also received feedback from other utilities around Australia.

What has been the response and feedback?

Responses from across the water and sewerage sector have been supportive. There are not many people who doubt the impending increase in network infrastructure reaching the end of its useful life. The data is fairly conclusive. However, the reference to an ‘infrastructure cliff’ was deliberately provocative.

Whether an asset deficit amounts to a ‘cliff’ really depends on how utilities restructure investment in renewal, relining and repair in coming years. Some are making large efforts to better understand the optimal mix of assessment, monitoring and rehabilitation.

Others may not be aware of how hard the problem is going to bite them. The reports provide some insight on how to achieve this balance in regional Queensland and what the total costs might be if things are left to the last minute.

What are the next steps?

The initial research was focused on mains due to their being buried and ‘out of sight and mind’. At the request of the industry, qldwater is incorporating the need for greater focus on strategic investment in the Roadmap for the Queensland sector which is currently in development.

There are also ongoing discussions involving councils, the LGAQ and Queensland Government about optimal solutions for efficiently addressing ageing water and sewerage infrastructure. Currently qldwater is exploring further research into other assets, particularly treatment plants across Queensland to examine future investment needs more broadly.

A major challenge is the diversity of our sector; multiple councils manage around 300 schemes with water and sewerage services many of which are very small. This diversity and the remote nature of many communities complicates the already difficult task of proactive investment in a sector that is essential to, but not always well understood by, the communities it serves.