Stormwater assets help to manage the rainfall in our city. This includes our drainage pits and pipes and also our water-sensitive assets, such as rain gardens and wetlands that help to keep our waterways clean.

We have recently completed a study of the capacity of the stormwater network to identify areas that need improvement to control flooding. The costs of these upgrades still need to be quantified. These costs will be assessed over time and will be reflected in future revisions of our Asset Plan and Financial Plan.

The replacement value of our stormwater assets is $288.9 million, representing 23.35% of our total assets.

Future challenges and opportunities

  • Development Density

    • Continued urban consolidation increases impermeable areas, resulting in increased stormwater runoff.
    • Strained capacity of the existing drainage network.
    • Strategic approach required to mitigate flooding and stormwater quality improvement initiatives.

  • Ageing Infrastructure

    • Lack of knowledge of condition of drainage network due to expense of analyse underground assets
    • Older stormwater assets are under capacity and require upgrade to improve flood protection.
    • Impacts of tree roots on drainage infrastructure.
    • Under-investment in drainage capacity results in increased maintenance costs.

  • Climate Change

    • Increase in both scale and frequency of extreme weather events leading to flooding.
    • Reduced capacity of existing current system to provide flood protection.
    • Desire to slow/detain stormwater through water sensitive design to enhance local amenity and reduce stormwater flow.

  • Environmental Sustainability

    • Increasing need to make use of stormwater runoff as a sustainable resource. This will mean that we will need to provide infrastructure to capture, treat and reuse collected stormwater and wastewater.
    • Ongoing maintenance costs associated with Water Sensitive Urban Design solutions.