Supporting the ground-breaking development of Rotokauri Rise.
Rotokauri Rise
Client: Tainui Group Holdings
- 1 endangered species
- 7 minutes saved per journey
- 700 people attended the community day
- 28,000 m³ spoil excavated and moved
Project Background
Located on the western side of Kirikiriroa (Hamilton), Rotokauri is close to amenities yet still enjoys the idyllic vista of the rolling Waikato hills.
Identified by Hamilton City Council as an attractive and sustainable growth cell, the area is undergoing significant development with a new ground-breaking residential development, Rotokauri Rise, currently underway.
Project Overview
The project's biggest challenge was due to the condition of the soils and the very shallow water table. The team encountered significant groundwater installing the stormwater and wastewater infrastructure with the aquifer approximately 1.5 to 2m below the existing ground level.
With the Rotokauri Drain running through the site, substantial rainfall in May and June 2022 lifted the water levels very high and caused flooding across the site.
Dewatering was a constant battle for the project team to overcome. Different techniques, such as dewatering spears, were used to pump thousands of litres of groundwater daily. At its height, nine six-inch dewatering pumps were utilised to keep the excavation dry.
Working with the shallow water table, commonplace for the area, prompted our first experience with dewatering spears. Due to its success on this project, we would readily look to utilise this method again where high groundwater is encountered.
Under the dewatering consent, stringent environmental controls and monitoring were required to ensure the adjacent Rotokauri Drain was maintained clear of silt and suspended solids. Weekly water samples of the drain showed that the controls in place were effective, an endorsement of the hard work the team put in to protect the surrounding environment.
The Dempsey Wood team, led by Jonathan Kay, showed great proficiency and resilience throughout the project.
Outcomes
Committed to enhancing equitable outcomes across all our projects, we work closely with our clients to optimise employment opportunities. While site staff numbers have fluctuated throughout the project, on average, 40 to 55% of employees identify as Waikato Tainui.
Additionally, we engaged with Kiwistaff, a non-traditional recruitment initiative that provides a bespoke matchmaking service and focuses on sustainable employment. As a result, one Kiwistaff employee was hired on our Rotokauri site, and we aim to increase this number on upcoming projects.
Through Alignz recruitment, we took three labour-hire employees to permanent contracts, with a fourth to join the DW whānau shortly.
Rotokauri experienced some fantastic community highlights hosting students from Tai Wananga Wharekura and Ngaa Taiaatia Kura as part of Smart Waikato's SSEP (Secondary Schools Employer Partnerships) programme and tribal members taking part in Te Waharoa – the Gateway to the Trades programme.
A very successful Digger Day was hosted in May 2021 for the wider Waikato community. With a BBQ, giant sandpit, face painters and digger demonstrations, the day saw several hundred people pass through the site, getting a bit muddy and embracing the water challenges.
