Since 2001, UWS’ Director, Neil Moody, has been a panel member and, for the past 16 years, the Chairman of the independent Criteria Review Committee overseeing Sydney Water’s sewerage modelling licence program.

Sydney Water maintains hydraulic sewerage network models for each Sewage Treatment System to support annual EPA reporting, evaluate system performance, and demonstrate compliance with the 2025–2030 STS licence requirements. The models are updated and validated annually using current rainfall and monitoring data and recalibrated when out of tolerance.

The validated models are simulated with a benchmark 10-year rainfall series. The resulting analyses identify changes in wet-weather overflow performance and inform regulatory compliance, overflow mitigation, and investment priorities. The audit methodologies and findings are subject to periodic review by the independent Criteria Review Committee.