Managing Bushfire Risk for Critical Infrastructure – Water Treatment

The bushfire emergency over the 2019/2020 summer highlighted the importance of protecting critical infrastructure from fire. The unprecedented scale of the recent east coast fires saw several water treatment plants severely damaged, causing significant issues for post-fire recovery.

Umwelt’s recent experience included bushfire risk assessment for the St Mary’s Water Treatment Plant in Sydney, NSW.

Additional process cycles were being added to upgrade the plant, and this required detailed bushfire risk analysis to support engineering design. The services included:

  • modelling bushfire hazard across the site to assess Bushfire Attack Levels (BAL) for all buildings and equipment
  • a review of proposed designs, particularly the new electrical switch room and the methane capture cycle
  • assessment of the fire history of the site and surrounding land uses
  • review of engineering design against modelled fire risk, and an analysis of potential design changes to address identified risks.

Sewage treatment is critical infrastructure and cannot be offline for even short periods. As a result a high level of bushfire risk assessment and mitigation was required to keep the facility operational under as wide a range of conditions as possible.

The principal challenge to overcome on the site was visualising the interaction between the fire risk and the underground services. As a water recycling plant, there was a dense network of water and power services underneath all parts of the site, and this constrained the placement of the new power supply.

The solution was to use a live GIS (ArcCollector tool in ArcGIS) that allowed us to overlay the Bushfire Attack Level model onto the design drawings of the site.

This allowed Umwelt’s bushfire assessors to show the design team where the bushfire hazard extended to, and then workshop as a group the potential design solutions to arrive at an optimum approach.

For further information, please contact our Principal Environmental Consultant – Bushfire, Cormac Farrell on 1300 793 267 or