What is On-Site Detention(OSD)?
In simple terms, it is a way of collecting the rainfalls on a site (known as stormwater), storing it temporarily and then releasing it slowly so that it does not worsen the downstream flooding.
Why do we need OSD ?
The aim of providing OSD for new developments or redevelopments is to delay and reduce the stormwater flows(discharge) from the pre-development levels, thus reducing flood risks caused by stormwater runoff.
What happen if there is no OSD ?
- Frequent surcharge at local drains
- Further bank erosion at local creeks
- Downstream flooding would get steadily worse
- Completed flood mitigation works would become less effective
- Community would suffer increased flooding
- Local council would be forced to spend more on further flood works
- Developers would have passed on the cost of dealing with the increased runoff to the rest of the community / council.
Which developments need OSD facilities ?
- Single dwellings, extensions, additions and improvements
- All commercial, industrial and special use developments and buildings
- Townhouses, villas, home units, duplexes
- Dual occupancies
- Tennis courts
- Roads, car parks and other sealed areas
- Public buildings
How do OSD look like ?
There are generally 3 types of OSD which is:
Editor:- Dilah – 11 March 14