Benefits

Benefit 1 - Biofiltration systems can remove heavy metals and hydrocarbons from stormwater

Biofiltration systems built in accordance with current best practice are very effective in removing heavy metals (Zhang et. al. 2012; Feng, et. al. 2012; Zinger & Deletic 2011) and hydrocarbons, while less effective for removing pesticides.

Benefit 2 - A submerged zone in biofilters enhances pollutant removal

The presence of a submerged zone in biofilters increases the overall removal of pathogens and nutrients (Payne, et. al. 2013 ^PDF).

Benefit 3 - Raingardens have 10% land take compared with wetlands for equivalent treatment

Raingardens are an effective way to remove sediments and nutrients from stormwater and require approximately 10% space of a wetland for equivalent treatment performance.

Benefit 4 - Biofilters are a low energy stormwater treatment technology

with the potential to provide both water quality and quantity benefits (CRC for Water Sensitive Cities, 2015, Adoption Guidelines for Stormwater Biofiltration Systems)

Benefit 5 - Streetscape raingardens can deliver uplift on property values

Project outcomes

Equivalent once-off payment

For every extra house that is

within 50m of a raingarden
within 100m of a raingarden

$36,000 per property
$54,000 per property

^{Polyakov M, Iftekhar S, Zhang F and Fogarty J (2015) The amenity value of WSUD infrastructure: A case study on raingardens. Proceedings of the 59th Annual Conference of the Australian Agricultural and Resource Economics Society. Rotorua, New Zealand.}