Watercare Services
Mairangi Bay, Auckland
June – October 2019
In 2019, Watercare engaged Cassidy Construction to design and build a new roof for the 63-year-old Kōwhai Reservoir. This followed the successful completion of a similar upgrade at the Pinehill Reservoir, also on Auckland’s North Shore.
The job involved engineered dismantling and removal of the reservoir’s aging 30m-diameter concrete dome lid, and installation of a robust modern roof made from a structural steel frame and longrun composite cladding supported by a central concrete column to ensure no excess load is added to the walls. This task needed to be achieved with minimal disruption to the residential neighbourhood and without damaging the reservoir, so our in-house engineers designed a safe demolition methodology using temporary internal scaffolding to prevent the seven-metre-high walls from collapsing inwards.
We began by cutting a small hole on the roof and propping the entire roof up with scaffolding. Then we cut the roof into 60 sections that weighed approximately 2.5 tonnes each, and craned them out using a custom-designed lifting jig. The pieces were then broken on site and sent to a concrete recycling facility.
We also carried out major upgrades to pipework and the inlet chambers, including constructing large concrete chambers that house new altitude valve sets to control water levels.
The project required close collaboration with Watercare and specialist subcontractors, and was completed within a tight schedule so the 4.6 million litre water asset could be returned to service as soon as possible.
Watercare Services
Mairangi Bay, Auckland
June – October 2019
In 2019, Watercare engaged Cassidy Construction to design and build a new roof for the 63-year-old Kōwhai Reservoir. This followed the successful completion of a similar upgrade at the Pinehill Reservoir, also on Auckland’s North Shore.
The job involved engineered dismantling and removal of the reservoir’s aging 30m-diameter concrete dome lid, and installation of a robust modern roof made from a structural steel frame and longrun composite cladding supported by a central concrete column to ensure no excess load is added to the walls. This task needed to be achieved with minimal disruption to the residential neighbourhood and without damaging the reservoir, so our in-house engineers designed a safe demolition methodology using temporary internal scaffolding to prevent the seven-metre-high walls from collapsing inwards.
We began by cutting a small hole on the roof and propping the entire roof up with scaffolding. Then we cut the roof into 60 sections that weighed approximately 2.5 tonnes each, and craned them out using a custom-designed lifting jig. The pieces were then broken on site and sent to a concrete recycling facility.
We also carried out major upgrades to pipework and the inlet chambers, including constructing large concrete chambers that house new altitude valve sets to control water levels.
The project required close collaboration with Watercare and specialist subcontractors, and was completed within a tight schedule so the 4.6 million litre water asset could be returned to service as soon as possible.