This paper presents the methodology used to develop Stormwater Management Areas

for Flow Control (SMAF) as proposed to be used in the Auckland Unitary Plan to manage

the small frequent flows up to the 1 in 1 to 2-year ARI that have the most impact on

channel erosion and stream health, that is, zones 1 and 2 in the above figure. The 1 in

1 to 2-year event corresponds approximately to the natural ‘bank full’ condition (the top

of the banks formed in the natural channel cross section) and thus have a significant

impact on the erosion of the channel.

David Kettle, Director, D&B Kettle Consulting Ltd

Ian Mayhew, Andrew Stuart Limited

Josh Irvine, Stormwater Modelling Team, Auckland Council

Damian Young, Director, Morphum Environmental