We’ll be installing a diversion structure in Elster Creek to divert overland floodwaters through the Elsternwick Park retarding basin and into the new drain. When there is a significant storm or flood event, the diversion structure will continue to let some low to mid flows down Elster Creek and Elwood Canal, but will redirect high flows through existing culverts under Bent Avenue, through the Elsternwick Park retarding basin and into the expanded inlet to the new drain (located in the south-western corner of Elsternwick Park). This will reduce flooding to properties downstream of Elsternwick Park.

The Elwood Main Drain Duplication Project will reduce flooding to more than 530 properties in Elwood and Brighton. If we installed a litter trap at the end of the drain, it would fill up incredibly quickly (we estimate in about 15 minutes in high rainfall events), which would cause the whole system to back up and create flooding, which is the opposite of what we’re trying to achieve.

Gross pollutant traps and litter traps get overtopped or bypassed in extremely high flows – this is how they’re designed so that they don’t clog up and cause flooding. These ‘end of system’ interventions are also not the best or most contemporary way to manage litter, as they don’t solve the issue of litter making it into our waterways and bays in the first place.

Around 95 per cent of litter that ends up in Port Phillip Bay originates from land and is washed into suburban stormwater drains. So it doesn’t make sense to simply ‘catch litter at the end’. The best way to address litter in the catchment is to manage it in a holistic way, driven by evidence-based data. We’re working closely with local councils in the area, as we know they play a strong role in preventing and minimising pollution and litter through their management of the land that feeds our stormwater systems.

The total volume and quality of water that will flow into Port Phillip Bay will not change as a result of the project. The only difference is that some of these flows will enter the bay approximately 1.6 kilometres further south of where it currently does. The new drain will simply redirect flows away from the Elwood Canal, which does not have enough capacity to carry large volumes of water in storms and high rainfall events, which is why the Elwood area floods so extensively.

Water quality improvements will be delivered under Bayside City Council’s masterplan for Yalukit Willam Nature Reserve, including a new wetland system which will help treat baseflows from Elster Creek and stormwater entering the wetland. This will help filter pollutants out from the water before it enters the bay.

Like you, we don't like seeing litter and pollution end up in our systems and into our waterways and the bay. Each year we spend $3-5 million cleaning litter from Melbourne’s waterways. If litter wasn’t such a problem, we could make better use of that money to achieve greater improvements to the amenity of our waterways and open spaces.

The best way to address litter in the catchment is to manage it in a holistic way, driven by evidence-based data. We’re working closely with local councils in the area, as we know they play a strong role in preventing and minimising pollution and litter through their management of the land that feeds our stormwater systems.