Stormwater management for new development
We've developed stormwater attenuation and bioretention design guidelines to help developers mitigate stormwater runoff and prevent increased flooding risks.
Council expects stormwater management solutions to be evaluated on an individual property and site-specific basis, taking into account the risk of flooding in the downstream catchment and the existing level of service.
These guidelines are provided to help developers and their representatives determine the acceptable solution, in combination with our Engineering Standards for Land Development.
Stormwater attenuation design guide
This guide outlines a list of possible options and includes the following:
- key requirements for stormwater attenuation tanks
- specific requirements for building consents
- links to resources
- information about soak holes and rain gardens
- a simple worked example.
Stormwater attenuation design guide(PDF, 2MB)
Residential bioretention design guide
This is intended to provide guidance for residential stormwater treatment, on a small scale, lot-by-lot basis. It covers:
- site conditions
- design components
- examples for planter beds, rain gardens and bioretention swales
- a simple worked example.
Residential bioretention design guide(PDF, 1MB)
Why stormwater management is required for new development
Council is required to ensure that the impact of new development on flood risks for existing properties is minimised and, where possible, effectively mitigated.
Ongoing residential intensification and infill development is resulting in greater impervious surface coverage and increased total and peak stormwater runoff. Without mitigation, this will increase the risk of flooding for some properties in some parts of the city.