An upgrade of Bridgewater’s sewer network is nearing completion, with SA Water ticking off major milestones by installing more than 100 metres of new sewer main and supporting erosion protection along Cox Creek.

The pipe – which travels beneath Cox Creek from a pump station located on Ayr Street – was built alongside an existing sewer main that has now been decommissioned as part of the upgrade.

A new flow meter and valve will be installed in coming weeks to complete the project, 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 could still be easily and safely accessed by our people,” Peter 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 in order to lay the new pipe.

“We’ll also plant native vegetation such as tubestock Poa labillardierei, which is a tussock grass, and Acaena novae-zelandiae – more commonly known as bidgee widgee – along the top of the new gabion wall to help it blend in with the surrounding environment.

“Following the completion of our project, the Adelaide Hills Council and Bridgewater Friends of Cox Creek will have the opportunity to restore native vegetation in the broader area we’ve been working in, with the cost of the new plants to be funded by SA Water.”

Ahead of the project, SA Water undertook a risk assessment of its sewer infrastructure and the surrounding creek banks, which identified 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,” Peter 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 in parallel to the old pipe to suit the hydraulic limitations of Bridgewater’s undulating landscape.”

All work as part of the sewer network upgrade is expected to be complete in November 2024.