Rain garden - Wanniassa (Lake Tuggeranong catchment)
Rain garden, Athllon Drive between Langdon Avenue and Fincham Crescent, Wanniassa
This new rain garden beside Wanniassa Playing Fields improves the quality of water flowing into Lake Tuggeranong in two ways:
1: The rain garden will filter and clean urban stormwater run-off, removing nutrients and pollutants that contribute to blue-green algal blooms.
2: It replaced an informal parking area which was causing erosion, with sediment flowing into the creek and Lake Tuggeranong when it rained.
It will also be a valuable educational resource for students at the adjacent St Anthony's Primary School, with rocks and seating in two areas designed to serve as outdoor classroom spaces.
The finished rain garden (comprising three separate pods) has a combined treatment area of approximately 2,315 square metres and remove around 20,000kg of nitrogen, phosphorous and suspended sediment every year.
One tree was removed but several new trees were planted. Casuarina Cunninghamiana match the existing trees and provide additional shade for the rain garden.
A two year macrophytes (water quality plants) establishment period has commenced. Establishment period refers to the process by which a plant becomes established in a new habitat.
During the final design phase, some changes were made to the original concept designs to accommodate services, community feedback and maximise water quality benefits.
- The final design includes three rain garden pods instead of two which will enable better distribution of the stormwater across the surface of the raingarden, resulting in healthier vegetation, fewer maintenance issues and better performance.
- The treatment area is 6.5% larger than in the design presented for community consultation, with a consequent increased treatment capacity.
- To reduce the potential for clogging of the filter media, the final design incorporates both a GPT and a sediment forebay. Together, these will remove approximately 90% of suspended matter from the stormwater, better enabling the raingarden to remove dissolved contaminants such as nutrients.
- To reduce the 'wear and tear' on the grassed areas, the access tracks for maintenance vehicles have been extended in the final design.
- Underground telecommunication cables will be re-routed to eliminate conflict with the western-most raingarden pod.
Find out what you can do on your own block to improve water quality in our lakes and waterways.
Landscape design plan
Click on the image to enlarge.