Clark Street Culvert – Renewal and Restoration

Client: Auckland Council

Aerial view showing renewal and restoration of Rewarewa Culvert, and the new pocket park and stream boardwalk in New Lynn.

Aerial view showing renewal and restoration of Rewarewa Culvert, and the new pocket park and stream boardwalk in New Lynn.

A major flooding event in March 2017 resulted in the collapse of stormwater infrastructure at the Great North Road to Clark Street intersection, and extensive flood damage to public infrastructure and private property. The flooding was caused by blockage of a 1500 mm culvert under Great North Road. Emergency works were put in place to isolate dangerous areas for public safety and to restore functionality to the existing infrastructure.

Following the storm event, Morphum Environmental was engaged by Auckland Council to assess options to provide for conveyance of flows, in the Rewarewa Stream under Great North Road. The options assessment resulted in the installation of an upgraded culvert and erosion protection structures, to increase culvert capacity to improve the existing service level, to convey flows up to the 100-year ARI event. The preferred option provided the largest amount of flood protection and allowed for construction to be undertaken while still maintaining traffic and pedestrian access.

The required works presented an opportunity to enhance the stream environment and social aspects relative to the New Lynn community. A stream boardwalk and community pocket park were created, through the collaborative efforts of Auckland Council, Fulton Hogan and Morphum Environmental.

Morphum Environmental provided engineers representative’s assistance and project support to the stormwater culvert upgrade, stream rehabilitation and elevated pedestrian boardwalk. In addition to this, Morphum Environmental was involved in preparing ecological impact assessments for resource consent applications, for both the emergency works of the collapsed stormwater infrastructure and the Rewarewa Stream boardwalk.

Key deliverables:

  • Options assessment for flood protection

  • Construction monitoring and administration

  • Progress management and financial monitoring

  • Environmental site management plan

  • Ecological impact assessment

  • Contract pricing negotiations

  • Design input and review

  • Monitoring of performance and contingency planning