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Good practice Imported

Watercare's Hūnua and Waitākere Native Forest Catchment Protection (Auckland, New Zealand)

New Zealand · Auckland · See the New Zealand profile · See the Auckland profile

Evidence: Descriptive / self-reported Top 81% 33/100 · Ask Evidence Copilot about this practice

Auckland's water utility Watercare is regenerating 2,000+ hectares of native forest in the Hūnua and Waitākere Ranges — source of ~84% of the city's water — spending at least NZ$15 million on planting over 30 years to protect water quality and defer costly treatment upgrades.

2,000+ ha
Native forest area under regeneration
NZ$15 million
Planned planting expenditure (30-year programme)
500,000
Native trees planted in record planting season
84%
Share of Auckland's drinking water sourced from Hūnua/Waitākere catchments
NZ$400 million
Cost of proposed new Waitākere treatment plant
Watercare's Hūnua and Waitākere Native Forest Catchment Protection (Auckland, New Zealand)

Details

Maturity
Scaling
Promoter
Watercare Services Limited
Period
{'end': '', 'start': '2017'}
Keywords
municipal water utility, native forest regeneration, catchment protection, forestry rights acquisition

Context

About 84% of Auckland's drinking water is collected from dams in the Hūnua and Waitākere Ranges, where largely native-forest catchments require comparatively little treatment before the water reaches the tap. Watercare, the council-owned water utility, treats this low-treatment-cost profile as a resource worth protecting: in 2017 it purchased forestry harvesting rights across former pine plantation land in the Hūnua Ranges, giving it direct control over land-use activities inside its own water catchments for the first time.

Objectives

The programme aims to protect catchment water quality and defer costly treatment upgrades by regenerating former forestry land with native forest, after the 2017 'Tasman Tempest' storm caused hundreds of landslips on forestry land that sent clay and silt into supply dams and made the water markedly harder and more expensive to treat.

Activities

The resulting 30-year programme is regenerating more than 2,000 hectares of former forestry land with native trees and plants, with Watercare planning to spend at least NZ$15 million on planting alone; in one record planting season it put half a million native trees into the ground.

Conclusions

Separately, Watercare's more recent push to build a new NZ$400 million treatment plant inside the Waitākere Ranges to replace the ageing Huia plant has drawn public and iwi opposition over native tree loss — a reminder that watershed protection and new infrastructure needs can pull in different directions even within the same utility.

Implementation
Indicative cost
Medium (€50k–€500k) — At least NZ$15 million budgeted for planting alone across a 30-year regeneration programme covering 2,000+ hectares; separate NZ$400 million capital cost for a related but distinct new treatment plant.
Time to results
Long (> 3 years) — 30-year programme beginning with the 2017 forestry-rights purchase; land regeneration and planting (including record 500,000-tree season) ongoing as of latest reporting.
Staffing & skills
Watercare Services Limited (water utility) land and forestry team

Conditions for success

  • Utility ownership/control of catchment land via acquisition of forestry harvesting rights, enabling direct land-use decisions
  • Sustained multi-decade funding commitment (NZ$15m+ over 30 years) for planting and land regeneration
  • Recognition of the direct financial link between forest cover, storm-driven landslip/turbidity events and downstream treatment costs

Common failure modes

  • Storm events (e.g. the 2017 'Tasman Tempest') can still generate landslips and turbidity from remaining forestry/former-forestry land irrespective of the programme
  • Watershed-protection goals can conflict with other utility infrastructure needs, as shown by public and iwi opposition to a new $400m treatment plant requiring native tree loss in the Waitākere Ranges

Where it fits

Governance type
council-owned water utility
Scale
city/metropolitan catchment (Auckland)
Income level
high-income

Commonly funded by

National / regional programmes

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Data sources

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