North West Growth Area on-site stormwater detention (OSD)
The impervious surface within the North West Growth Area is increasing significantly due to development, resulting in larger volumes of stormwater runoff and much higher stormwater peak discharges. This has the potential to damage our natural creek systems, and/or cause local stormwater flooding and major river flooding.
We are building large regional flood detention basins that are funded through Section 7.11 developer contributions to mitigate these risks.
We may also require permanent OSD to support our regional flood detention basins and/or temporary OSD until regional basins are completed.
OSD is used to control the peak flow of stormwater and then control its discharge to limit damage.
The map Land zoned under north west growth area SEPP - on-site stormwater detention (OSD) requirements indicates the areas that require permanent and temporary OSD, and areas where the regional flood detention basins have been completed.