PROJECT DESCRIPTION
In 2014 WSP was initially engaged to conduct a condition assessment and reinstatement options study. This was due to age related deterioration of the rubble mound breakwater. Significant volumes of stone and sand accretion had also blocked the leeward lifeboat slipway in the years following the 2010-11 Canterbury earthquakes, necessitating ad-hoc dredging. The source of the accreted material was determined to be cliff collapses at Sumner Head updrift of the site.
Subsequently WSP were engaged to proceed with design development of the preferred breakwater reinstatement option in 2016, including stakeholder and council requested enhancements and dredging, through to the completion of construction in 2017.
In addition to coastal and civil engineering design WSP provided the full range of associated in-house professional services for successful project delivery, including:
- Stakeholder engagement – Consultation with the lifeboat institution, surf lifesaving club, residents’ association, historical society, recreational boating, fishing and surf clubs, Runanga Iwi and statutory authorities.
- Surveying and modelling – Topographic and bathymetric surveys for digital terrain and 3D design models, and simplified wave modelling, including UAV photogrammetric ‘as-built’ baseline surveys for future condition monitoring.
- Assessment of environmental effects – Ecological and archaeological inspections and assessments for resource and heritage consent applications.
- Contract documentation – Production of tender/contract documents (including specification, drawings and bill of quantities).
- Contractor procurement – Tender assessment in accordance with CCC processes, and field and laboratory testing and assessment of the contractor’s proposed armourstone quarry.
- Construction – Contract administration (NZS 3910), engineering / MSQA observation, archaeological monitoring, ornithological assessment and ‘as-built’ surveys and record drawings.
PROJECT CHALLENGES
High profile local project with multiple stakeholder and user interests.
OUR APPROACH
- Comprehensive site study and assessment.
- Collaborative community engagement.
- Integrated consultancy services provision.
- Application of technology and international best practice coastal engineering design.
OUTCOME
- Enhanced breakwater reinstatement design with improved hydraulic and overtopping performance to cater for future sea level rise.
- Improved wave conditions in the lee of the breakwater roundhead for the lifeboat operations and recreational boat ramp usage.
- Deepened slipway access channel to enable ‘all-tide’ lifeboat launch and recovery.
- Permanent ‘restricted access’ ramps for future breakwater maintenance and slipway dredging.
- Improved crown road and car parking.
LIST OF PRIMARY SERVICES
- Advisory
- Design
- Construction Management
- Archaeology
- Resource Consent Planning
- Civil Engineering
- Coastal Engineering
