River Intake Structure
Date: July 2013
We were engaged by Fonterra to upgrade the raw water intake from the Waikato River, for the factory water supply to the Te Rapa site.
The upgrade involved replacing the existing aging steel sheetpile channel with a submerged passive screen and buried intake pipeline. The project began with the assessment of daily and peak supply flows required at the factory and an assessment of low river levels to confirm the placement of the new intake screen.
A peak daily flowrate of 28,000m³/day was required by the factory and special consideration was given to supply this volume at times of future low river levels during 1 in 100 year low flows. The design required an 800OD diameter gravity intake pipe constructed within the existing channel to reduce the volume of excavation and mitigate environmental effects associated with working on the banks of the River.
Construction of the replacement intake was undertaken during the small window when the Factory was in ‘shutdown’ mode during July. At this time the River level fluctuated approximately 3m due to winter storms providing a challenging environment for the Contractor.
Structural elements to protect the screen against debris strikes and river bed scour/accumulation were included in the design and provided confidence for Fonterra.
A very high level of health and safety was expected by the Principal and this was stringently adhered to by the Contractor with regular liaison between the Engineer and Fonterra.
Our supervision and management of the construction provided an efficiently run project and with the Principal and the Contractor the project was brought in on time and under budget. The final product has provided Fonterra with a raw water intake that has a minimal environmental footprint, is pleasing to the eye and provides the Te Rapa factory with its present water requirements as well as allowing for future growth.
- Procure and construction administration
Date: July 2013
PDP had the challenge of balancing the client’s objective to upgrade the intake during the Factory’s shutdown period.
PDP was responsible for ensuring the design complied with all aspects of the resource consent including flow, velocity, navigational clearance and environmental protection.
The work involved:
- Hydrologic and hydraulic assessment
- Managing river modelling and assessments
- Preliminary and detailed design
- Construction estimates and tender evaluation
All the design, pipe work design and process equipment selection was done by PDP. The construction documentation was prepared and run under NZS3910.
PDP activities included:
- Preparation of all design and contract documentation
- Coordination between suppliers and site engineering staff and overall project planning
- Construction administration