Fitzroy Gardens is a one of Melbourne’s iconic inner city garden parks and attracts 2.8 million visitors per year. The site is high profile and has been operated by the City of Melbourne as a public garden since 1917, with the land originally set aside as a public reserve in 1848. The Gardens are now home to many significant tree and plant species both exotic and Australian natives. The WSUD (Water Sensitive Urban Design) stormwater harvesting project was required to provide greater water security to the gardens during period of drought as well as reducing the overall use of potable water for irrigation.
The spatially efficient Biofilta system was chosen by the City of Melbourne to harvest stormwater from a 67ha urban catchment which includes the runoff from Parliament House to provide up to 69 million litres of fit for purpose irrigation water for the Fitzroy and Treasury Gardens. This represents over half the total irrigation demand for the 33ha of heritage listed gardens.
Working with design engineers Cardno, this system was designed to intercept two main drains and filter the gross pollutants and sediments before temporarily storing a massive 4,000,000 litres in an underground tank acting as a mini urban catchment. From the primary tank, the stormwater is pumped up through our specially constructed 247m2 Biofilta vegetated planter containing our own blended sand media and tolerant native plants.
As the water passes through the treatment bed, the combination of physical and biological treatment processes removes suspended sediments and the attached pollutants such as heavy metals and soluble nutrients from the water. Excess pollutants such as Nitrogen and Phosphorus promote algal blooms in the Yarra River and Port Phillip Bay which can detrimental to their ecological health.
The Biofilta system greatly reduces these pollutants to help protect our natural environment. Up to 48% of all total Nitrogen, 57% of Phosphorus and 85% of total suspended solids are predicted by MUSIC modelling to be removed from the catchment, easily exceeding current Best Practice Environmental Standards for this major urban catchment. Our smart control systems work to optimise the watering regime to manage the planter vegetation and health of the biofilms to work at their best and meet the demands of the irrigation system. After treatment through the Biofilta vegetation, the cleansed stormwater water drains to a 1,000,000 litre reuse tank where it ready to be utilised by the City of Melbourne to irrigate the gardens.
Contact us today to find out how Biofilta can meet your needs for spatially efficient stormwater harvesting and precinct scale pollutant removal.