Business South November 2021

50 | Waterfall Park project comes up trumps T Russell Fredric CONTRACTING Wilson Contractors: Civil Contractors Otago Awards O tago-based Wilson Contractors has won two 2021 Civil Contractors NZ Otago Branch awards. The family business managed to trump larger national construction companies for a complex roading infrastructure project at Waterfall Park near Arrowtown, garnering an environmental award plus the award for projects over $5 million It was especially satisfying for Wilsons to win an award on a highly sensitive site that not only had an ecologically important creek running through it, but also because the creek flowed into Lake Hayes which has received much publicity about long-standing environ- mental issues. The project is part of developer Winton’s luxury development within the picturesque Ayrburn and Waterfall Park through which Mill Creek flows past heritage buildings to be remediated and on into Lake Hayes. Wilson Contractors’ chief executive Steve Osborne says it was a difficult project “with many moving parts”. “Works were carried out under a tight pro- gram with difficult environmental constraints. We are happy the teams work has been recog- nised by leading specialists in the construction industry.” The project included creating two diversions for new creek crossings. These crossings were both concrete box culverts with a combination of in-situ and precast elements used. “The design stage was a collaborative process, allowing the designers, pre-caster and on-site crew to all influence the design to simplify and reduce the onsite build time. “This in turn reduced the risk of working in a sensitive environment with a tight deadline caused by consent conditions only allowing work requiring creek diversions within a tight four month period. “Covid-19 added to the pressure to then cut this four month period even shorter.” Hazardous work was undertaken to reme- diate contaminated soil onsite from previous historical farming operations, removing about 2000 cubic meters of contaminated soil to a sealed on-site encapsulation cell. Extensive temporary works design and construction was also required. This included a temporary bridge, crane pads, haul roads, shoring, form work, propping and scaffolding. Site engineer for the $5.5m project, Isaac Harrison, says it was an interesting and com- plex project, in a beautiful location. “Environmental concerns added quite a significant extra stage. The extensive sedi- ment run-off controls included cut-off drains, sediment ponds, decant systems and silt traps at the onset. It was essential we protected Mill Creek at all times.” “There’s been a big emphasis on achieving a high-quality, high-end result. It’s been good to be able to deliver this.” Roading work, including a new intersec- tion on Arrowtown-Lake Hayes Road, overall required 20,000 cubic metres of earthworks, three waters infrastructure, and utilities. Achieving the awards was a collaborative effort between Winton, Wilson Contractors, consultants and subcontractors, Queenstown Lakes District Council and Otago Regional Council. “Wilsons would like to thank all involved.” Because of the project’s complexity, Wilson Contractors considerable experience over many years was a key to its success. This year’s awards follow nine others in various categories for projects completed in Otago and Southland over 10 years, includ- ing the 2020 Civil Contractors NZ Southland Branch Open Award for, Invercargill sewer main project and the 2020 Otago Branch Environmental Award for Tuckers Beach Trail, Queenstown. Headquartered in Queenstown, Wilson Contractors has branches in Cromwell and In- vercargill and staff based throughout Central Otago and Southland.