The Filterra® Bioscape® is a collaborative approach with stakeholders to deliver a water-sensitive design solution that is only a fraction of a traditional rain garden. This is showcased at the Kayelene Place site in Ōmokoroa collaborating with Western Bay of Plenty District Council, Maven, CB Civil and Vitruvius Ltd to deliver a great solution in a tight space where conventional systems wouldn’t fit.
While the footprint is smaller, the site has a lot of challenges and restrictions. Consideration has to be taken during design since the Council Stormwater reserve is right next to the stream as the receiving environment, high rainfall events can increase the water level on the stream and surcharge into the Filterra® Bioscape® system. Future water level rise can also surcharge into the Filterra® Bioscape® system. Raising the Filterra® Bioscape® can also cause flooding on the upstream catchment so had a restricted level where the Filterra® Bioscape® can fit. There is also a flooding risk on the Stormwater Council reserve, a high bund was designed to prevent any flooding from washing/scouring the system.
BENEFITS OF THE FILTERRA® BIOSCAPE®:
Originally the treatment system specified was a Rain Garden and Swales for the 5.6 hectares catchment. The original Rain Garden footprint needed to be approx. 1,315m². The council-owned stormwater reserve land was not big enough for the 1,315m² of rain garden. Also, the Rain Garden had to be installed next to the road, however, since the roads are next to steep land, the rain gardens need a structural retaining wall which increases the cost significantly.
The specified Filterra® Bioscape® only needed 205m² of footprint, which now can be fitted solely in the Stormwater Council reserves.
The Filterra® Bioscape® can treat at the same level as the Rain Garden but at a fraction of the footprint.
The single location of the system and reduced footprint reduce the cost of maintenance and overall lifecycle to the council.
Using native plants in the Filterra® Bioscape® to promote Te Mana O Te Wai.
Working with the council, we will install a display to educate the local community on what the system is for and create ownership with the community.
TARGET CONTAMINANTS AND MAINTENANCE:
Targeting sediment, heavy metals and nutrients.
The maintenance is simple and easy only requiring the replacement of the layer of mulch on top every 6 months.
