746-26-376-AC - Orakei Basin Boardwalk - ECI and Construction

Orakei Basin Boardwalk, a key connection in the Glen Innes to Tamaki cycle way, is located along the Northern end of the Orakei Basin, along a double-tracked rail embankment, inside the KiwiRail rail corridor.

The boardwalk was originally built in 2009 and widened in 2018/19. When the boardwalk was widened, the deck was replaced over the full width, but the substructure from 2009 remained.…

Orakei Basin Boardwalk, a key connection in the Glen Innes to Tamaki cycle way, is located along the Northern end of the Orakei Basin, along a double-tracked rail embankment, inside the KiwiRail rail corridor.

The boardwalk was originally built in 2009 and widened in 2018/19. When the boardwalk was widened, the deck was replaced over the full width, but the substructure from 2009 remained. In 2020, the handrails were replaced after feedback from the community. At the eastern end of the boardwalk, there is a bridge that spans across the spillway for the sluice gates.

The boardwalk is used by over 1,300 users per day and there is no easy alternative route. It is a well-loved and highly appreciated asset to the community and to commuters to and from the CBD.

Recent inspections of the boardwalk have identified displacement of the handrails on the eastern end along the railway side of the boardwalk. Following further investigation, it was found that the piles under the old (2009) section of boardwalk had decayed and been significantly affected by teredo worm – to the point that some piles no longer support the structure.

A 2.5m wide, 230m long section of the boardwalk has subsequently been cordoned off as a safety precaution pending implementation of a remedial solution.
Stage 4 of the Glen Innes to Tamaki cycleway has commenced to the west of Orakei Basin (Section 4 – Orakei to Tamaki Drive) and when that is completed in Q4 of 2026, this will complete the full cycleway from Glen Innes to Tamaki Drive.

It is therefore essential that the proposed construction methodology for Section 3 remedial works:
• Completes all works prior to Stage 4 go-live.
• Maintains continuous public access along the cycle way during the Stage 3 works

An ECI model is proposed as there is a need for:
• constructability advice for the final stages of design, particularly focussed on the design of boardwalk foundation system and substructure elements.
• need for early procurement of some long lead time items (i.e. significant number of steel piles which may need to be procured overseas).
• support required for consenting, stakeholder management and programming to meet the time constraints and coordination across multiple sites.