Restoring drinking water during Auckland’s 2020–21 drought, from a temporary plant producing water in 61 days to a new 12 ML/day permanent plant.

Client: Watercare Services Limited
Services: Civil and structural engineering, temporary works
Location: Papakura, Auckland
Scale: 12 ML/day · 61 days to first water · 100+ workers on site daily
Status: Complete 2023

01 / Project overview

The brief

During Auckland’s 2020–21 drought, Watercare’s water sources fell to critically low levels. Watercare identified the decommissioned Papakura Water Treatment Plant, fed by the Hays Creek Dam, as a way to urgently restore local supply. That meant delivering a temporary treatment plant at speed, followed by a new 12 ML/day permanent plant on the same brownfield site – automated, operationally stable and compliant with the Drinking Water Standards for New Zealand.

Watercare engaged us directly for civil and structural engineering. We mobilised a team of 30 within an integrated design team alongside process, mechanical and electrical designers across New Zealand and Australia. The site was tight, two existing reservoirs had to stay in service for both plants, and COVID-19 was disrupting supply chains.

02 / Our approach

How we delivered it

Designing at emergency pace

The programme left no room for conventional formal design reviews. Instead, we set up discipline-based working groups with Watercare, the contractor and the wider design team to coordinate design and document every decision. Early contractor involvement let us deal with material availability during design, reducing COVID-19 procurement risk.

Civil and structural design

In-house, we delivered underground pipework, roading and pavements (including Civil 3D surface modelling), bulk earthworks, temporary works to manage stormwater runoff, and full structural design of foundations, pipe supports and framing. We also coordinated geotechnical, survey, utility investigation, traffic management and consenting inputs, and our design supported a construction workforce of more than 100 people on site each day.

Keeping the reservoirs working

Overhead view of the treatment plant: reservoirs, solar-panelled process building and site roads

Drawing on our reservoir inspection work for Watercare, we identified early that both reservoirs were in average to poor condition, so remedial works could be planned. Pipework to and from the reservoirs was reconfigured to suit both stages. When the scour line failed its pressure test, a temporary plug kept the reservoir in service, and an externally operated mud valve replaced relining – cheaper, and with no confined space entry.

03 / The outcome

“The temporary plant was producing AA-graded drinking water within 61 days of the early contractor involvement phase. The permanent 12 ML/day plant, completed in January 2023, now runs as an automated, compliant asset, and the project won Excellence in Water at the 2021 IPWEA Awards.”

04 / Gallery