Building new water infrastructure usually takes years. Exemplary public health is the driver for these projects, where details need to be spot on to ensure assets are safe, reliable and resilient. But with Auckland in drought during 2020, the teams at Watercare and Brian Perry Civil had mere months to come up with a solution to add resilience to the region’s water supply.
Fortunately, scarcity breeds creativity, as the saying goes. With a commitment to collaboration, innovation and daily tai chi, the project team took just 61 days to reinstate the disused Papakura Water Treatment Plant site, which feeds from the Ōtūwairoa/Hays Creek Dam in the Hūnua Ranges.
The $68-million project to re-establish a water treatment plant (WTP) on the site was always in Watercare’s plans, but was accelerated by the drought, which led to the decision to do the build in two stages.
The first stage, completed in January 2021, included the construction of a temporary treatment plant and the replacement of the Papakura No. 2 water main from the old treatment plant on the site to the intersection of Hūnua and Dominion roads. With the drought over and the temporary plant now offline, stage two is well underway with an advanced, state-of-the-art, permanent WTP due for completion later this year.
When up and running, the facility will be able to process up to 12 million litres of water each day. But that’s not before the temporary, stage one solution resulted in a much‑needed six-million-litre-a-day boost to Auckland’s water supply while the city recovered from drought.
The successful build led to the project winning the Excellence in Water Project category at the recent Institute of Public Works Engineering Australasia New Zealand Asset Management Excellence Awards, and being highly commended at the Civil Contractors New Zealand Awards. It also received an operations award from Water New Zealand.
Watercare Operations Commissioning Manager Axel Dumont says completing stage one was a feat of teamwork and problem solving to come up with an innovative solution amid multiple constraints. ‘These wins are a chance to acknowledge and celebrate what can be achieved with a collaborative approach between a motivated client, a determined contractor, bold subcontractors and innovative suppliers – everyone went above and beyond to meet the brief.’
The project was complex due to the congested site, the lifting sequence of large plant and equipment, the ‘build to commission’ nature, the limited ability to plan too far ahead, and limited working hours with neighbours in close proximity.
Dumont adds that the outcome is a worthy showcase project that demonstrates technical excellence, collaboration, innovation, and exceptional health and safety standards – while bringing tangible relief to the Auckland community.
Central to the project was the use of LEGO-like modular and containerised treatment and chemical systems that are designed to be relocated. This also enabled offsite fabrication with easier installation – key to ensuring an expedited program.
‘It’s not the first time this type of mobile, temporary design has been used, but it’s certainly the biggest project of this type we’ve done,’ says Dumont. ‘It was made possible because we were able to draw on all of our previous experiences to create something better.
‘Through this process, we’ve also established a design that can be replicated for future projects – removing design cost, and other barriers to innovation and action.’
From the build, the tanks, vessels, pumps and equipment have already been adapted and incorporated into stage two – minimising waste and the overall project cost. The remaining temporary infrastructure now forms part of Watercare’s mobile water treatment systems fleet, and supports temporary works for infrastructure delivery projects.
Other key components from stage one included installing 150 tonnes of water treatment equipment: a flocculation clarifier system, two membrane trains, a dual UV treatment container, four granular activated carbon containers and containerised chemical dosing systems.
The team also installed all the site-run polyethylene and stainless steel pipework, as well as electrical cable and tray. They also completed difficult structural repairs to existing reservoirs, and new interconnecting and outlet pipework.
The project was set up as part of Watercare’s Enterprise Model, which focuses on building long-term partnerships with contractors to realise benefits in three core areas: sustainability, cost and safety. Dumont says this meant Watercare was able to undertake early contractor involvement with Brian Perry Civil (BPC) so the teams could work – and problem solve – together, from the start.
BPC Completions Operations Manager Kate Loveridge says co-locating and planning together for the three months before construction started was invaluable in mitigating risks and optimising the 61-day ‘build to commission’ program.
‘The fact that we had real collaboration and support from Watercare to feed into the design and safety aspects in particular was very evident when we got to site and started to build. An example of this was the ability to lift in all of the equipment within four days of being on site, which gave the mechanical and electrical teams the best start to the program. What would normally be a major complex lift was done without a hitch from day one and was a direct result of our work together offsite as designers, constructors, and planners,’ says Loveridge.
Technology also became a vital tool in ensuring accurate and precise communication between all parties.
Lean construction tool Last Planner was used and overlapped several trade streams – detailing key milestones communicated via an interactive whiteboard, real-time drone shots, 3D modelling and 360-degree videos.
‘This was useful when the civil team needed to excavate the trench and lay polyethylene pipe under the high‑voltage powerlines, and the mechanical team had to install large‑diameter pipes,’ explains Loveridge.
‘Both teams had to agree on how to connect the pipes, as the design was not practical. This critical activity had to be resolved late on a Friday, as the following week’s work depended on it being complete.’
This was just one of many challenges that the teams worked through on the build. At its peak, about 120 staff members were working on the small construction site, which created both logistical, and health and safety challenges. These were addressed by dividing the site into multiple work areas and having people work within their area, which reduced the amount of people and equipment moving between the working areas and around the site. A shuttle bus service was set up to run between the site and the satellite car park and fabrication yard in Papakura – reducing cars and other vehicle movements on site.
The summer temperatures and lack of shade on site led to measures like water stations being set up, electrolytes provided for people’s water bottles, ice machines made available and increased breaks during the day. Tai chi classes were held on site so that the construction crew could learn and practice mindfulness techniques. This enhanced their concentration so they could return home safely to their families every day.
Dumont credits the overall success of the project to the passion and dedication of the teams involved. ‘We wouldn’t have been able to deliver this new plant in such a short time frame without the teamwork between our people, the BPC team and the crews on the ground – so a huge thank you goes to everyone involved.’
All images courtesy of Watercare.