Once the water has been collected at the intakes from the rivers, or is drawn from the aquifer, it enters a treatment plant.

There are four treatment plants in Wellington (Te Marua, Wainuiomata, Waterloo, and Gear Island), they are owned by Greater Wellington Regional Council.

The Ministry of Health has established guidelines for safe drinking water: the Drinking Water Standards for New Zealand 2005 (revised 2008). Our treatment methods are designed to produce water that meets these standards and satisfies the needs of our customers.

Te Marua water treatment plant

The water treatment plant, pumping station and storage lakes at Te Marua were built between 1980 and 1987, to treat water taken from the Hutt River at Kaitoke. The plant has a design capacity of up to 140 million litres daily (ML/d), but typically treats around 60 ML/d on average. Water from the Te Marua treatment plant is also stored in the Stuart Macaskill lakes.   Read more

Wainuiomata water treatment plant

The Wainuiomata water treatment plant receives water from the Wainuiomata and Orongorongo rivers and three smaller creeks (Georges, Big Huia, and Little Huia). The plant's design capacity is 60 million litres per day (ML/d), but production is typically around 30 ML/d or just under 20 percent of total supply each year. Wainuiomata is the newest treatment plant in our network, opened in 1993.   Read more

Waterloo water treatment plant

Eight wells supply water from the Waiwhetu aquifer, beneath Lower Hutt, to GWRC's Waterloo Water Treatment Plant, which was commissioned in 1981. Waterloo has a maximum production capacity of 115 ML/d, but typically produces about 60 ML/d or roughly 40 percent of our total annual supply.   Read more

Gear Island water treatment plant

Gear Island water treatment plant sits beside the Hutt River at the eastern end of the Petone foreshore. The plant was commissioned in 1935 and, like Waterloo, treats water from the Waiwhetu aquifer.   Read more

Waiwhetu Aquifer - chlorination

Greater Wellington Regional Council has approved the permanent chlorination of Lower Hutt drinking water. The Council voted in favour of a recommendation from Wellington Water, based on our Waterloo Wellfield Water Quality Contamination Investigations Report. Access the report in related documents at the bottom of this page.   Read more