Raingarden - North Stradbroke Island Hotel, QLD., Australia - Case Study

• Project Location: North Stradbroke Island Hotel, QLD., AUSTRALIA
  
• Project Details: Raingarden for Stormwater Infiltration
  
• Completion Date: October 2007

During the latter half of 2007, the redevelopment of the original Hotel site began. The entire site was reshaped and new buildings and service infrastructure installed.

As part of the redevelopment, two rainwater harvesting systems were proposed. One on the seaward side of the development which filters roof water and is stored for re use in an Atlantis 80,000 L Harvesting Tank. The Bio Retention and Harvesting System encompasses Stormwater Detention, Bio Filtration, Infiltration and Storage of Treated Stormwater. The Atlantis System is designed to harmonise in the landscape as a natural feature. The roof water is directed via pipe network to a head wall approximately in the centre of the basin.

Carpark runoff is also directed to one end of the basin via a headwall and rock drain which also encompasses footpath drainage.

The Profile of the basin is a mixture of soil profiles to maintain permeability while allowing biological filtering of the stormwater. The top layer is approx 300mm deep, and is made up of 60% washed coarse river sand and 40% mature organic loam. Surrounding the two inlet headwalls river stones are placed to prevent scouring and act as water diffusers. There is a high level inlet to comply with hydraulic requirements.