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Hutt and Wainuiomata/Orongorongo water collection areas

Hutt and Wainuiomata/Orongorongo water collection areas

Updated 17 November 2021 1:41pm

Managing water catchments

Ki uta ki tai - from the mountains to the sea, water is life

(Whaitua committee)

Wellington relies on safe and reliable drinking water. Most of this water comes from the Hutt and Wainuiomata/Orongorongo water collection areas. These areas supply around 60% of Wellington's water, with the remainder is comes from the Waiwhetu aquifer system below the Hutt Valley.

Safe and reliable drinking water doesn't arrive at your tap without planning and managing the bush and forest in the water collection areas - and that's part of our job at Greater Wellington Regional Council to help Wellington Water deliver good quality drinking water to you.

Managing threats to water quality

The Hutt and Wainuiomata/Orongorongo water collection areas are rugged and remote areas with forests. We need to actively manage threats that may impact on water quality including controlling plant and animal pests. Plant pests include gorse, lotus, and wilding pines. Animal pests include deer, goats, possums, rats, stoats and weseals.

People and vehicles can carry weed seeds and diseases into these areas. To minimise the chance of this happening we ensure that all vehicles entering the collection areas are cleaned on entry. On guide walking tours people are checked to make sure they have clean boots and equipment.

Restricted access

We restrict and limit access to these areas to reduce the risk of water contamination. Hunting is allowed but you need a permit in both catchment areas but limited to the roar season in the Wainuiomata/Orongongo catchment.  Nearby GWRC and DOC regional parks including the Remutaka, Tararua and Pakuratahi Forest Parks and the Kaitoke Regional Park provide full recreation access for Wellingtonians to get out and enjoy the great outdoors near to their city.


As part of routine management, we monitor the water collection areas to identify threats to water quality and supply. We check forest vegetation health and look for loss of vegetation cover from pest animal browsing. We monitor rainfall and stream flows.

Wellington Water continually monitors water quality, looking for organisms such as giardia and cryptosporidium that can make people sick.  

Hutt and Wainuiomata/Orongorongo Water Collection Areas management plan

The management plan for the Hutt and Wainuiomata/ Orongorgono Water Collection areas outlines how Wellington Water and GWRC will work together to help ensure that enough clean water is delivered to meet the Wellington region's needs with a minimal amount of intervention at the water treatment plants.

You can find out more about protection of our water catchment areas by downloading the:

Water Catchment Management plan information sheet

Water Catchment Management plan summary sheet

Hutt and Wainuiomata Orongorongo Water Collections Areas Management Plan