Journey to Success - Raetihi WTP Upgrade

The Raetihi township water supply was contaminated in September 2013 as a result of a diesel spill incident to the Headwaters of the Makotuku River in the Tongariro National Park. The spill occurred at the Turoa ski field which is 27 kilometres away from the intake. This resulted in the drinking water supply being interrupted for 21 days while the plant and reticulation network were cleaned and a temporary supply was installed. At the time of the incident the treatment was basic with surface water abstracted into two raw water settling ponds and a chlorination system. This incident highlighted the inadequacy of preventive measures at the existing plant for the drinking-water supply scheme.

In order to achieve DWSNZ compliance as soon as possible, Ruapehu District Council (RDC) in partnership with Veolia developed and implemented an improvement programme. This secured Capital Assistance Funding from Central Government enabling a long term solution to be implemented in a high deprivation population.

In July 2018 the upgrade to the WTP was completed. Water safety and resilience of the supply are now compliant with DWSNZ.

After completion of the upgrade, the community were invited to come together for an orientation day. Posters, group tours and a live streamed Facebook presentation, followed by an edited video were all used to communicate the upgrades to the new plant, and provide feedback to the community around works completed and security of the supply.

This paper describes the approaches that RDC and Veolia have used in upgrading the Raetihi WTP to ensure water safety, achieve DWSNZ compliance, and overcome the financial and time challenges. It also provides an overview of the upgraded WTP including its performance, and lessons learnt along the journey.