Rangitāiki River Scheme Review (Edgecumbe Floods)

Sue Powell | Oct 12, 2017

Last week, Sir Michael Cullen presented the findings of an independent review of the Rangitāiki River Scheme to the Bay of Plenty Regional Council. Tregaskis Brown was commissioned to independently manage the process on behalf of the Bay of Plenty Regional Council. The review was commissioned to look into the circumstances that led to the breach of a floodwall in Edgecumbe in April 2017, leading to the destruction of 15 homes and extensive damage to a further 250. 

The review examined the Council’s approach to managing flood hazards, and how that translated into the operation of the Rangitāiki River Scheme.

Key findings of the review:

  • The reasons for the actual floodwall failure are complex, as a series of factors contributed to the failure of the floodwall.
  • There were a number of issues that led to pressure on the system that protected Edgecumbe, that may have resulted in a different outcome had they been resolved.  These included design issues, delays in implementation, and a lack of management of residual risk to a community that existed in a location that was vulnerable to flooding.

Sue Powell , Partner, said “it was a pleasure to work with Sir Michael Cullen, Kyle Christensen from Christensen Consulting, and Charlie Price from Stantec during the review.  Tregaskis Brown is proud to have played a part by providing the wrap-around support that enabled the panel to operate at arms-length from the council in undertaking this review."

Please click here  to view the Panel’s findings.

In undertaking this role, Tregaskis Brown convened additional expertise from Pete Fitzjohn of Counsel Communications, and Tim Power from Power Law to support the review process.  


The issues encountered in the review are not uncommon in our experience.  Themes in this case that we frequently see in complex change processes include:

  • managing multiple and divergent stakeholder interests;
  • the gaps that emerge between strategy and implementation as implementers struggle to give effect to new approaches that will take many years and significant investment to implement;
  • the challenge of managing the risks that emerge in the interim; and
  • the added complexity when responsibilities are shared across different agencies.  

Tregaskis Brown has deep experience in managing difficult problems, and these problems are most deeply felt in the public sector where agencies are dealing both with complex problems with divergent stakeholder interests, and challenging implementation issues.