River landscape and dredging design to manage increasing flooding in Christchurch

At a Glance

  • $16M

    Project Value

  • 35K

    Cubic Metres Sediment Extracted

Location
Christchurch, New Zealand
Offices
Client
  • Christchurch City Council
Partners
  • WSP Opus
  • ENGEO
  • Jacobs

Heathcote Ōpāwaho River Dredging Design

Managing surface water became a critical focus for Christchurch City Council following the City’s earthquakes in 2010 and 2011, particularly in combatting sedimentation rates and flooding.

Dredging helps reduce the severity of smaller flood events as it deepens and widens river channels. The project set out to provide immediate relief to nearby properties affected by flooding.

Our job was to fast-track design of the dredging profile and associated bank and river landscape works to manage increasing flooding in Christchurch—not a straightforward engineering solution. Along with providing flood relief, we needed to minimise environmental impacts and enhance the planted areas.

Community activities were integral to our design as locals use the Heathcote/Ōpāwaho for leisure activities and whitebait/īnanga fishing, a custom important to Māori culture.

Community feedback to our proposal was positive as our design had great spin-offs, for example the locals were delighted with the removal of over a hundred white poplar trees which they saw as weeds. Their dense foliage had created a ‘dark area’ where people regularly partied so clearing it eliminated the associated rubbish build-up and created picnic and sitting areas instead.

At a Glance

  • $16M

    Project Value

  • 35K

    Cubic Metres Sediment Extracted

Location
Christchurch, New Zealand
Offices
Client
  • Christchurch City Council
Partners
  • WSP Opus
  • ENGEO
  • Jacobs

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