The completion of a $6.6 million project has improved the security of the Waikato District’s drinking water supply.
Four new reservoirs at Ngaruawahia, Hopuhopu, Huntly and Pokeno mean that Waikato District Council’s drinking water storage capacity has increased by 9.75 million litres.
A range of contractors were instrumental in the completion of the work, within budget. GHD carried out hydraulic modelling, detailed design and consenting along with sub-consultant Ergo Consulting for electrical design and specifications. Spartan Construction as head contractor carried out all the earthworks and civil pipework. Reliant Solutions undertook construction of foundations, reservoirs and pipework within reservoir foundations. Permastore supplied detailed reservoir design and materials from Spain and Calibre Consulting provided structural and detailed design for foundations. And McKay completed the works on electrical and control systems.
The work required extensive collaboration with stakeholders, who played a crucial role in the success of the project. These included Heritage New Zealand, local iwi Ngaati Tamainupo, Turangawaewae Marae and Waikato Tainui, and utilities providers WEL Network, Counties Power and Kiwi Rail.
Council’s Project Manager for the work Richard Clark said the new reservoirs are an integral part of Council’s long-term strategy for better security of drinking water supply in the district, particularly in the central area. “That strategy recommended having a minimum of 24 hours’ water supply should other treatment systems fail and require a temporary shutdown for maintenance. The extra reservoirs cater for that,” he said.
Basically the reservoirs build resilience in the water supply network, according to Council’s Waters Manager Karl Pavlovich. “We now have a minimum of 24 hours of water storage across the central area of the district and Pokeno,” he said. “In addition to storage volume, these reservoirs also provide pressure improvements to parts of the network and enable further residential development in the district.”
The reservoirs have a manufacturer’s certified material warranty of 20 years and a design life of 50 years.