As climate patterns become unpredictable and water security more fragile, integrated water infrastructure systems that can adapt to both flood and drought conditions can build resilience in vulnerable communities. Stormwater harvesting is poised to transform water management in Australia by unlocking greater supply and delivering strong economic, social and environmental outcomes.
Collecting and treating stormwater from urban areas using integrated infrastructure has positive, long-term benefits, according to Kurt Jensen, General Manager (Victoria and Tasmania) at Atlan Stormwater Australia.
“What we do today has an impact on society for the next 100-plus years,” he said at the Engineers Australia’s webinar on practical applications of stormwater harvesting. “With water, we have to remember that it’s not ours to keep, it’s ours to share.”
Modern stormwater management incorporates sustainability practices, capturing pollutants and preventing flooding to help future-proof cities. Stormwater assets intercept contaminants in urban catchments before they can flow downstream and pollute lakes, oceans and rivers. Dual-purpose systems combining on-site stormwater detention (OSD) and stormwater harvesting provide water for reuse and manage local flooding – and are supported by stormwater treatment devices.
Building in these functions in water infrastructure projects across Australia has significant environmental and economic benefits, Jensen told the thought leadership webinar jointly hosted by Atlan Stormwater.
Supporting conventional detention systems that hold excess stormwater but remain empty until rain events, Jensen advocated for more multi-use retention and detention assets. These innovations look to improve site efficiencies, detaining stormwater to avoid flooding in storm scenarios, and storing captured stormwater for an array of other potential uses during dry periods.
“We put in a lot of detention tanks, which are designed to run empty,” Jensen said. “But with the advancements in artificial intelligence and control systems, I think there’s a big missed opportunity in having a system that retains water from the back of a rain event, stores it for re-use and then can release stored stormwater when forecasts predict upcoming rain.”
Water quality management
Jensen addressed concerns about water quality, particularly hydrocarbon contamination from roads and car parks. Stormwater inflows can be treated for many pollutants, including sediment, nutrients, heavy metals, gross pollutants and hydrocarbons. Capturing these at the source in urban catchments prevents them travelling downstream or into stormwater tanks.
“Stormwater harvesting is not just a technical challenge, it’s a fundamental shift in how we value and manage water,” Jensen said. “So the real question isn’t whether it’s possible, but whether we’re bold enough to make it happen at scale.”
Technological advancements such as weather monitoring, apps and sophisticated modelling could lead to smart tanks that can adjust their water quantity in real time.
Stormwater harvesting in action
There are many commercial and residential examples of engineers combining stormwater retention with harvesting infrastructure.
In Knox City Council’s Dobson Park and Tim Neville Arboretum, a comprehensive system provides treatment capacity for up to 3 million litres of stormwater daily. The installation includes stormwater management with Atlan’s Flowceptor device, a 575,000-litre above-ground panel tank, tertiary treatment systems, wetlands and storage ponds that are connected via radio link to ensure the operation runs seamlessly.
An OSD solution in Cowes, Victoria, shows how harvesting can increase housing density and develop community spaces. The 3.1 million litre system uses AtlanChamber technology and replaces traditional green infrastructure with underground chambers. This increases development opportunities by maximising land yield through subsurface installation.
At Balmoral Park, a municipal-scale project harvests water from a 50-ha catchment, storing 1.7 million litres in AtlanChamber systems for sports field irrigation. Intelligent monitoring systems maintain water quality through real-time measurement of pH, electrical conductivity and turbidity. This installation addresses flood management while also delivering a reliable non-potable water source.
Potential for significant cost savings
Harvested stormwater could deliver significant savings. It costs between 50 cents and $1.50 per kilolitre compared to $2-5 per kilolitre for potable water, Jensen said.
“With that sort of difference and gap, you’ll have a very quick return on investment on stormwater harvesting,” Jensen said.
Melbourne uses an estimated 350 gigalitres of potable water annually, with only 10 gigalitres sourced from stormwater or rainwater harvesting. Jensen believes this is an opportunity to dramatically expand stormwater harvesting.
Stormwater harvesting systems also lower overall water use and water bills and reduce the load on water networks. They could build drought resilience and water conservation by allowing stormwater to be recaptured and stored during wet periods to use in dry conditions.
Innovations in storage
Innovation in stormwater storage has boosted project efficiency and expedited installation timelines. AtlanCube is a geocellular underground tank system built with recycled materials, which offers a 97 per cent void ratio for water storage and requires only two components per cubic metre.
“It’s exactly the footprint of an Australian standard pallet, which is the most efficient way to store an underground structure and move it around to get it to site,” Jensen said.
For projects requiring larger capacity or different configurations, the MegaVault precast concrete system was used in a recent data centre. Engineers installed a hybrid solution that included both detention for stormwater management and retention for cooling tower supply and toilet flushing, finishing a 1.5 million litre installation in just eight days.
These modular systems can be configured to meet specific project requirements while maintaining the strength needed for various surface uses, including concrete-based artificial sports fields and car parks. Modular designs allow stormwater assets to be delivered to site ready to install, reducing project delays and improving quality control and logistics.
Atlan’s range of locally manufactured modular systems can be configured to meet specific project requirements and development areas. Fully trafficable and suitable for subsurface installation to increase land yield, Atlan’s water quantity range includes precast concrete tanks AtlanVault and MegaVault, AtlanChamber’s open bottomed arched infiltration system, and geocellular tank system AtlanCube.
Specialising in the design, manufacture, installation and maintenance of stormwater harvesting systems – Atlan provides a wide range of treatment assets, stormwater tanks, pump stations and management systems. Their design team is experienced in assisting developers, engineers and councils to configure treatment assets and water quantity infrastructure to suit project scale, scope and budget.
Learn more in Engineer Australia and Atlan Stormwater’s latest webinar, Practical Applications of Stormwater Harvesting.
