Stormwater Management Devices for the Auckland Region – Success in Our Sites

One of the consequences of city growth is that stormwater runoff occurs in greater volumes and higher velocities. To mitigate this, and still allow our city to grow, Auckland Council has adopted an approach which recognises the importance of preserving and enhancing natural hydrology as part of the infrastructure development process. The Unitary Plan, with its strong emphasis on incorporating green infrastructure into urban design, allows for high development growth while maximising social, cultural and environmental outcomes.

To achieve this, it was important that Council produced design approaches for implementing water sensitive design for stormwater management, so that developers and their designers and contractors can achieve the outcomes required by the Unitary Plan. Stormwater Management Devices in the Auckland Region (GD01) provides detailed interpretive designs for implementing these green infrastructure provisions.

In developing this document, Auckland Council’s Engineering and Technical Services Department has changed how we develop technical guidance. We have engaged comprehensively with internal experts, industry and Mana Whenua, as well as elected officials, from scoping onwards, to develop this guideline to replace TP10 for maximum user friendliness. The document contains concise specifications for building wetlands, bioretention devices, swales, pervious paving and green roofs, along with other devices, presented in a clear and user friendly format.

This paper presents some of the key challenges that were faced in undertaking an integrated consultation approach including:

Consultation:

• Developing a Community of Practice with diverse stakeholders from diverse backgrounds
• Working with Mana Whenua to align the outcomes with core cultural values
• Aligning expectations across the region and communicating the new approach

Interpretation:

• Teasing out the key differences between the Unitary Plan provisions and its predecessor, the Air, Land and Water Plan
• Interpreting provisions around imperviousness

Design and approach:

• Allowing the right people to have a voice around design and specifications
• Finding consensus on how to design complex site-specific devices such as wetlands

2018 Stormwater Conference

Although the process has not been without its challenges, the result is an approach to water sensitive design that paves the way for building a greener, more resilient city. As Auckland grows, so should its natural health and liveability.