What is onsite stormwater detention (OSD)?
If our existing drainage system can’t cope with an increase of runoff, an onsite drainage (OSD) system is a requirement of the planning process.
An OSD system helps retain stormwater onsite during heavy rainfall and releases water slowly through a constrained outlet. This limits peak discharge from the site.
Local developments that have the potential to increase stormwater runoff will generally need an OSD system.
How much does it cost?
The cost will be $550 to $1250. We base our fees on the number of units or apartments proposed on the plan.
Extra costs apply if you need to make changes to your OSD plans.