The project involved the conversion of grassland, previously beef grazing land, into a large nursery site at the base of the Brynderwyn Hills near Waipu, beside SH1.

Site works involved removing topsoil, reshaping the clay subsoils and then capping it with compacted rock before it was covered with weedmat and irrigation to form the nursery hardstand.

Running underneath the nursery is the subsurface drainage system. The design of the system flows to a central stormwater spine which conveys the water to a storage dam, but with very little gradient across the system finding the right pipes was key to the success of the project.

“The height of the ends of the nursery areas are a maximum elevation of 1m, so the whole area has very little head pressure to push the stormwater out the 0.3% gradient of the drainage spine,” says Terry Wearmouth, Director for Kauri Park, the company behind the nursery development. “In the future 5000m² of the nursery site will be covered in a glasshouse.”

To cope with the limited gradient of the site and the differences across the site – between the covered and uncovered nursery areas – Wearmouth says it was determined that one side of the drainage spine needed a 630mm pipe while the fully open side needed a 800mm pipe.

After talking through the options, the team decided EUROFLO® pipe was ideal for the project.

“The service and advice from P&F Global were great.”

“The drainlayers had not used EUROFLO® before this project but commented on how light and strong the pipes were. Compared to concrete pipes in this situation, where the groundwater was higher than the pipe work and the area had to be pumped dry, the process of laying the pipe was completed easily four times faster than concrete and with half the labour.”

Wearmouth says the P&F Global team were also supportive when instructions from the engineers called for larger pipe sizes, making it easy to manage returns and replacements.

In addition to finding the pipes lightweight, the drainlayers found the installation of the EUROFLO® pipes very straightforward.

“One experienced drainlayer could run a team with little experience due to the simplicity of installation.”

“We had an excellent experience with EUROFLO® and would definitely recommend this product for ease of handling and installation. The twin skinned pipe conveys the stormwater as well as any other smooth walled pipe,” says Wearmouth. “We’re looking forward to seeing how they perform in heavy rains.”

WHAT: EUROFLO® Pipe
WHERE: Nursery on the corner of SH1 and Glenmohr Rd, Whangarei District, Northland.
WHEN: Nov 2018 – May 2019
WHO: Kauri Park Nurseries, Reyburn & Bryant, and Clements Contractors

 Download a copy of the case study here