Wellsford ditches Hoteo River for bore water

Watercare has identified a new groundwater source for Wellsford as part of a $1 billion plan to upgrade water and wastewater infrastructure for the northern parts of Auckland over the next 10 years.

Assuming Watercare can secure appropriate consents, the new source, off Wayby Valley Road, will replace the Hoteo River as Wellsford’s primary water source. Watercare spokesperson Maxine Clayton says groundwater has a number of advantages over river water. It is not subject to the same seasonal fluctuations as a river – particularly during a drought – and requires less treatment because it is a protected source.

“Rivers are usually surrounded by farmland and may be contaminated to a greater or lesser extent by herbicides, fertilisers and so forth,” she says.   

Moreover, it’s anticipated the Hoteo will not have the capacity to meet Wellsford’s projected growth in the coming decades.

Warkworth switched to bore water in December 2018, which subsequently led to a barrage of complaints about residue build-up in plumbing fittings and appliances due to the higher mineral content (hardness) of the water, in particular the presence of silica.

But Watercare principal water quality scientist Tatiana Derevianko says the new groundwater source in Wellsford is lower in both total hardness and silica, compared to other groundwater sources managed and operated by Watercare.

A treatment plant will be built in Wellsford to handle the bore water, which is likely to be completed in the early 2030s.  

Details of the Wellsford bore water plan are contained in Watercare’s new Asset Management Plan 2021-2041, which was published this month.  

The plan noted that Warkworth’s population is expected to quadruple over the next 25 years and over the next decade there will be a major focus on an upgrade to area’s wastewater system.

When complete, a pump station in Lucy Moore Park will pump Warkworth wastewater to a new wastewater treatment plant at Snells Beach via a deep-underground tunnel. Once treated it will be discharged into the ocean, south of Martins Bay.

Watercare has allocated finances for the project and hopes to secure a resource consent and begin construction later this year.