As areas become more developed, the proportion of land that has an impermeable surface (a surface through which water cannot pass and that sheds water) increases.

This results in more water running into the stormwater system at a faster rate, which can overload the network if not addressed through planning controls or infrastructure upgrades.

The 2GP contains performance standards which limit the percentage of a site area that may be covered with impermeable surfaces to manage this issue.

Variation 2 has introduced some additional examples into the definition to clarify this standard, specifically:

• paved areas including driveways and sealed/compacted metal parking areas
• sealed and compacted metal roads; and
• layers engineered to be impervious such as compacted clay

In the residential zones, impermeable surfaces cannot cover more than 50-80% of a site’s area, depending on the particular zone. To reduce the impact of intensification rezoning in Variation 2, the ‘Variation 2 mapped area’ has been applied to new General Residential 2 zoned areas. The mapped area has the effect of limiting impermeable surface coverage to a maximum of 70% of a site’s area (the limit for General Residential 1 Zone) instead of the usual General Residential 2 Zone maximum of 80%.

The Variation 2 mapped area has not been applied to pre-existing areas of General Residential 2 Zone. It also applies other rules not related to stormwater management.

For further information, contact Emily McEwan on 477 4000.