As developments keep growing, some local council stormwater systems are under pressure. To alleviate the pressure on the stormwater system – local councils now require new developments to have an on-site detention and retention system. Also commonly known as OSD tanks. The purpose of OSD tanks is to slowly release the rain-water collected back into the storm water.
A typical on-site Detention and on-site Retention system will often look something like this:

Retention – In retention water tanks the water below the OSD is used for re-use. In short, the water under the OSD fitting can be stored and used by the home-owner at a later date. Read the rest