Water Done Well: the new era of water delivery

Fulton Hogan Rapid Capture

Queenstown Lakes District Council

An iPhone-based app developed by Fulton Hogan’s Engineering Solutions is helping Queenstown Lakes District Council (QLDC) make the right calls on its extensive range of water assets.

QLDC has tens of thousands of assets across its 137 pump stations and treatment plants – from pressure sensors to large pumps, switchboards and HVACs.

‘FHRapid Capture’ has been developed to record all individual assets and their condition for QLDC to prioritise maintenance requirements and investment.

QLDC Asset Engineer, Sultan Akhmatov, says good asset management starts with good asset information, and a clear understanding of the infrastructure communities rely on every day.

“Knowing what assets we have, what condition they’re in and where the risks lie helps us plan maintenance and renewals with confidence, prioritise future investment and continue delivering reliable water services across Queenstown Lakes,” Sultan says.

“We’ve appreciated the collaborative approach and the shared focus on building asset information that is practical, reliable and useful for the teams managing these services every day.”

Engineering Solutions is Fulton Hogan’s specialist arm for developing new, and enhancing existing, systems.

Lateral thinking behind team’s horizontal drill

New Plymouth District Council

Fulton Hogan’s Environmental Solutions and Taranaki Water teams are showing potable water lines can be laid through contaminated soil without disrupting the substrate – and saving money in the process.

During an early contractor involvement (ECI) exercise with New Plymouth District Council, Foreman Josh Lehrke identified an opportunity to horizontally drill a 210m length of 250 OD water line using a special aluminium pipe with polyethylene outer layer.

Known as Protecta-Line, the pipe is relatively common in Europe on contaminated brownfields sites to ensure drinking water is uncontaminated, but is new locally, especially for horizontal drilling.
The alternative would have been to trench a ductile iron pipe in the traditional way, disposing of the 315m3 of arsenic and chromium contaminated soil. At circa $350 per tonne for disposal, this would have cost $110,250, excluding traffic management and plant and labour associated with excavation costs. The team thus reduced the project cost by more than $200K on the approximately $600K job.

Project Manager, Te Amorangi Simeon, says while directional drilling is common for HDPE pipe, this may be the first time Protecta-Line pipe has been used locally to place pipework through contaminated soil. The approach also avoided the need for a resource consent, being within permitted activity guidelines.

Heatmapping wastewater pipes

Hastings District Council

Fulton Hogan is helping keep our ‘arteries’ clear, using GIS (geographic information systems) to heat map the wastewater pipes that criss-cross our towns and cities.

The heatmaps highlight areas that are most prone to the build-up of anything from rags and wipes to fatberg residues and sanitary products. They also identify tree roots and cracked pipes, all presented on an interactive map in real time with zoom-in charts.

The more intense the colour on the map, the bigger the problem area. By identifying the areas most prone to clogging, councils are in the best position to make timely investment decisions for maintenance or capital works.

Harania Creek Flood Resilience Project

Auckland City Council

There are few better examples of climate mitigation than the Harania Creek Flood Resilience Project in Mangere, Auckland.

When the 19km Central Interceptor sewage line was built across Harania Creek in 1964, a culvert within an embankment was sufficient for the creek to make its way to the Manakau Harbour, even in the worst storm.

Almost 60 years on, the Harania catchment was among the worst affected areas in Auckland’s January 2023 floods. More than 60 homes were damaged, of which 13 presented intolerable risk to life should there be a repeat event.

The City Council’s Healthy Waters team responded by asking Fulton Hogan to undertake the technically challenging task of re-routing the 2.5m diameter central interceptor by way of a 3.2m Infrapipe HDPE pipe to keep the interceptor operating while building a pipe bridge and installing a 37m, 1800mm diameter and 111 tonne pipe on the bridge.

The Harania Flood Resilience Project is a key project in Auckland Council Healthy Waters’ Make Space for Water programme. The programme is to reduce flood risk and improve infrastructure resilience by increasing stormwater capacity, upgrading critical wastewater networks and ensuring waterways are adequate for severe weather events.

Wānaka wastewater treatment plant

Queenstown Lakes District Council

The expanded Wānaka wastewater treatment plant is one of the best examples of critical infrastructure being fundamentally upgraded in a live, high-risk environment while maintaining service, safety and community confidence.

In one of New Zealand’s fastest-growing communities, the wastewater treatment plant was nearing capacity. Alongside design consultant, Beca, Fulton Hogan delivered major upgrades for Queenstown Lakes District Council (QLDC) within a fully operational live plant, involving complex staging, 12 critical tie-ins, and tightly controlled shutdown windows while maintaining uninterrupted wastewater treatment.

The upgrade has more than doubled treatment capacity, increasing average flow from 3,796 m³/day to 7,873 m³/day and peak wet weather flow from 7,701 m³/day to 16,130 m³/day, providing capacity for around 30 years of projected growth.

The project also included four innovations:
– in-situ tank construction to Wānaka Airport
– a revised inlet structure installed largely as precast to shorten programme exposure
– a steel coffer dam for work in a live decant tank, and;
– a bespoke diffuser lifting mechanism to allow future maintenance while the basin remains live.

These innovations reduced risk, improved quality, protected programme and improved the long-term operation of the asset.

As QLDC project manager Trent Beckman-Cross said:

“Tying in a significant extension to this plant without halting the treatment process presented a challenge in itself. But with the plant being at, or near capacity, the margin for error was even lower. I am proud of this project and of the positive learnings that are being applied to other projects, as a result.”

Te Marua Water Treatment Plant

Wellington Water

In just 10 months and inside a stretch target, Fulton Hogan built a new dissolved air filtration (DAF) system for Wellington Water, adding 20 million litres per day to Wellington’s network. We have since added two further DAFs, bringing Te Marua’s capacity to 140 million litres per day.

In doing so:
– Traditional processes for new asset procurement and integration were streamlined for accelerated construction.
– WTP operators were closely involved in the design’s review and sign-off, ensuring shared responsibility, maximising teamwork and readying them for the plant’s future operation.
– Multiple test runs ascertained the condition of assets for critical tie-ins, enabled asset renewals and helped identify additional servicing needs.
– All just 30 metres from a major fault line, requiring planning and construction to account for a one-in-2500-year earthquake.

“Moving at pace is challenging on any major project. But when it involves the careful co-ordination of asset development and management teams and their sometime diverging interests, and a system-wide awareness of potential ‘upstream’ and ‘downstream’ effects, it is at another level.”

Wellington Water’s Chief Advisor for Drinking Water, Laurence Edwards.