Challies Island Bridge

Project Info

Client: Fulton Hogan

Project Description

Taylors constructed a moveable bridge across the Waimea River in Tasman to minimise the environmental impact of the new Challies Island quarry.

Fulton Hogan has a consent to extract the gravel from the Challies Island site and remediate the extraction sites into wetlands. Fulton Hogan has contracted Taylors Contracting to complete the gravel extractions.

KEY ACHIEVEMENTS
The 30m bridge allows 80-tonne (laden) rigid dump trucks to cross the river from the 22ha Challies Island site on the west bank, to the Appleby processing plant one kilometre downstream.

It can be removed in 48 hours if a major flood is predicted, and ensures no vehicle comes into contact with the water, eliminating sediment discharge and allowing continuous unimpeded fish passage.

The Challies Island 30m bridge allows 80-tonne (laden) rigid dump trucks to cross the river from the 22-hectare Challies Island site on the west bank.

The Challies Island bridge was an interesting technical challenge. Developing the bridge concept required innovative problem-solving and required significant financial investment from Taylors Contracting.

Fulton Hogan have a consent to extract the gravel from the Challies Island site and remediate the extraction sites to wetlands. Fulton Hogan have contracted Taylors Contracting to complete the gravel extractions.

Gravel extraction takes place over a specified period of time during the year which will have minimal impact on bird populations.

The bridge is designed and installed with consideration to the dynamic river flows and the consent requirements to not create erosion of the riverbed. Other considerations, such as not creating a navigational hazard to other river users (jetboats and kayaks), were incorporated into the design and installation.

Taylors are responsible for consent compliance during a forecast flood event which stipulates the bridge must be removed if the temporary foundations become compromised. Our flood response plan was developed by Dave Robinson and refined after each large rainfall event and elevated river flow. Further development of the process will be required through the coming years once the location of the next bridge site is identified.

Key Achievements
The bridge can be removed within 48 hours if a major flood is predicted and ensures no vehicle comes into contact with the water, eliminating sediment discharge and allowing continuous unimpeded fish passage as well as access for other river users.

The Bridge Project was a success from two standpoints:
Designing and Installing a relocatable bridge, which is a huge testament to the skill and capability of our Workshop team who constructed it from modular components with little to no instruction from the manufacturer.
Working within the strictly controlled river environment in a specified timeframe fell to the Project Management team of Nelson Civil Department. Construction of the bridge abutments, monitoring river levels during the extraction process, and fulfilling volumes to the client in full and on time.

Challenges
During gravel extraction there is ongoing community sensitivity in relation to this job. That requires us to be diligent around our communications with the community and our methodology.

The main challenges are noise and dust which are proactively managed to stay within required limits.

Te Mana o Te Wai, or mana of the water, is about recognising the vital importance of clean, healthy water for maintaining the health of our water bodies, freshwater ecosystems, and the communities that rely upon them for their sustenance and wellbeing.

Related Projects