The SewerFix Wet Weather Alliance (SWWA) is implementing a program of work that aims to improve the waterways of Sydney and meet Environment Protection Authority licence requirements by reducing the frequency of wet weather overflows from 13 sewerage systems. The program team is responsible both for planning (problem identification, optioneering and approvals) and delivery (design, construction, commissioning and handover) of overflow abatement solutions.
The program team has worked across the Sydney metropolitan area from the northern beaches to the Illawarra and in the Blue Mountains. Overflow abatement solutions have ranged from minor upgrades in a sewerage system (e.g. raising weir crest levels or providing storage) to the $46M Northern Beaches Storage Project – an 18ML, aboveground tank located in Brookvale that captures wet weather flows that would otherwise overflow to Curl Curl Lagoon. The total value of the program is in excess of $300M and the alliance has been operating for over six years.
The Program Alliance Agreement includes painshare/gainshare provisions for key result areas (KRAs) including cost, time, safety, environment, community and quality. The team has performed at a high level as measured by key performance indicators (KPIs) for these KRAs, with the KPIs tightening over time as lessons have been learned and new performance benchmarks have been set by the team on completed projects.
Sydney Water has also used SWWA as a vehicle to deliver other projects that have required high levels of expertise to ensure successful outcomes. One example was the planning and delivery of upgrades to the drop shafts between sections of the Blue Mountains Sewerage Tunnel to mitigate risks to the assets and the community during extreme wet weather events.