Completion imminent for Bridgewater sewer upgrade

SA Water is ticking off major milestones in its upgrade of the Bridgewater sewer network by installing over 100m of new sewer main and supporting erosion protection along Cox Creek. The project will be completed by November 2024.

The pipe was built alongside an existing sewer main that has now been decommissioned as part of the upgrade. To complete the project, a new flow meter and valve will be installed in the coming weeks, along with the reinstatement of a small creek crossing and revegetation of native flora in the immediate work area.

SA Water’s Senior Manager of Capital Delivery, Peter Seltsikas, said construction was temporarily paused while the utility revisited the designs and location of the flow meter and valve.

“This approach ensured we could optimise their design and install them in an area away from the public that our people could easily and safely access,” Mr Seltsikas said.

“Importantly, given the sewer main travels under Cox Creek, the flow meter measures the volume of sewage moving through the pipe at any given time – enabling us to detect if it experiences a leak or break.

“Once the meter and valve are installed, our crews will reinstate an existing small creek crossing by carefully placing rocks of a similar size, which we needed to remove to lay the new pipe.”

Ahead of the project, SA Water undertook a risk assessment of its sewer infrastructure and the surrounding creek banks. The assessment identified that the creek channel had become significantly wider over time due to erosion.

Mr Seltsikas said sewer networks are designed to take advantage of gravity, with pumping mains also needed depending on the area’s topography.

“As a result, some of our infrastructure is often located parallel to watercourses to use gravity to carry sewage from higher points in the network to our pump stations, such as the existing pipe along Ayr Street,” Mr Seltsikas said.

“This pipe collects sewage from around 70 homes upstream and discharges it at our pump station.

“At this point, the sewage is pumped into our new sewer main that runs under Cox Creek, which was laid parallel to the old pipe to suit the hydraulic limitations of Bridgewater’s undulating landscape.”

Image: SA Water