Responding to a 100 Year Storm - An Actual Example in Auckland

A short duration, high-intensity storm, hit northern Auckland on 3rd July 2012. The 10-30 minute duration intensities reached 1% AEP. This storm caused the worst flooding experienced in northern Auckland since 2000 and resulted in 70 buildings being flooded.

This paper outlines the actions taken by Auckland Council’s Stormwater Operations Group in responding to this heavy storm and their field observations. The focus of this paper is as follows:

• Brief analysis of the storm event based on actual rainfall records
• Council’s response to this storm
• Causes of the reported flooding problems based on field observations

This paper also suggests actions to enable improvements in the work practices of people working in the stormwater and building industries and how to avoid similar problems of this nature in future.