Diversifying our water sources helps secure our water supply system against droughts and floods. Using alternative water sources to meet demand makes better use of all the water available to us, and saves drinking water for specific purposes where high-quality water is needed.
As part of a holistic approach to water management, we are working closely with the retail water companies and councils to harness alternative water sources in local communities.
We supply the retail water companies with highly treated recycled water from our wastewater treatment plants. This can be used for many non-drinking purposes, such as providing water for:
public spaces like parks, gardens and sports grounds
household toilets, laundries and gardens
Stormwater can be collected and used for many purposes – including watering sports grounds, parks and gardens, and replenishing wetland habitats.
Stormwater harvesting schemes typically collect water from Melbourne Water or council-owned drains, then store and treat it before it is used. Treatment methods include mechanical water treatment plants and natural systems such as wetlands, which reduce the amount of pathogens and pollutants in the water. The amount of treatment needed depends on how the water is used and its quality, which varies according to where the water came from and how often it rains.
Water sensitive urban design treatments
Water sensitive urban design helps protect waterways by improving stormwater quality and reducing the amount of runoff. There are a variety of techniques ranging from large-scale green roofs to household raingardens.
Rainwater tanks capture the best quality rainwater directly from roofs, before the water becomes polluted from the ground or drainage system. The Victorian Government has information about installing rainwater tanks, and offers rebates to homes and businesses.
Sewer mining recycles water at a local scale by removing sewage from mains and treating it on-site – before it reaches the treatment plant. This produces high quality recycled water that can be used nearby, while waste by-products are returned to the sewerage system.
Sewer mining plants are usually small and use a combination of conventional filtration, biological, membrane and disinfection processes.
Groundwater is found below the earth’s surface in the pores and crevices of soil and rocks. It is considered an alternative to surface water, and has supplemented water supplies in some severely drought-affected areas in Victoria.
Bores and wells are used to extract groundwater from aquifers – underground layers of rock, gravel, sand or silt that allow water to pass through.
Groundwater is vulnerable to drought and climate change, so we manage and monitor how it is allocated. We are also researching ways to use recycled water for replenishing aquifers.