Te Kaitaka/Greenslade Reserve

Location: Northcote, Tāmaki Makaurau / Auckland, Aotearoa New Zealand
Project type: Municipal urban open space and stormwater infrastructure
Delivery/lead organisations: Auckland Council (Healthy Waters), Kāinga Ora, Eke Panuku, Kaipātiki Local Board, mana whenua, design consultants
Date/period: 2020–2023
Scale: Site / Neighbourhood
Primary system or theme: Urban stormwater and flood management; blue–green infrastructure

Context

Why this site matters
Greenslade Reserve sits within the Awataha catchment, a highly urbanised area of Northcote with a history of surface flooding linked to constrained piped stormwater infrastructure. 1 The reserve forms part of the wider Te Ara Awataha Greenway, which repositions public open space as multifunctional flood and stormwater infrastructure within an intensifying urban area. 2,3

Challenge or constraint

What wasn’t working/what needed to change
Frequent flooding in the Awataha catchment placed pressure on downstream neighbourhoods and the Northcote town centre, while conventional underground upgrades alone offered limited capacity for extreme rainfall events. 1,4 The challenge was to increase flood storage and peak-flow attenuation without removing valued recreational open space.

Intervention

What was done
Greenslade Reserve was redesigned to operate as a floodable landscape that provides stormwater detention during heavy rainfall while remaining a functional sports and recreation reserve during normal conditions.

Key components

  • Lowered sports field designed to temporarily store stormwater during storm events
  • Subsurface drainage infrastructure enabling the controlled release of detained water downstream
  • Integration with the Te Ara Awataha Greenway network and associated blue–green infrastructure
  • Associated wetland planting and stream corridor upgrades linked to the Awataha Stream

Implementation notes

Design and delivery considerations

  • Sports field levels and surfaces were engineered to tolerate periodic inundation without permanent loss of recreational function 1
  • Flood storage capacity was designed to complement, not replace, existing piped stormwater infrastructure
  • Performance depends on coordination with upstream catchment interventions delivered through the wider greenway programme 2
  • Ongoing maintenance is required to manage sediment deposition and turf recovery following flood events

Outcomes

Observed or reported outcomes

  • The reserve is reported to be capable of temporarily holding several million litres of stormwater during extreme rainfall events 1
  • During the January 2023 extreme rainfall event, Greenslade Reserve and associated greenway infrastructure reportedly functioned as intended, reducing pressure on the downstream stormwater network 1

What is plausible but unmeasured

  • Reduced frequency and severity of nuisance flooding in adjacent streets and downstream areas
  • Increased public awareness and acceptance of floodable public open space as infrastructure
  • Incremental water quality treatment benefits from associated wetland and riparian planting

Evidence and limits

What the evidence supports
Council reporting indicates that floodable open space at Greenslade Reserve provided effective temporary stormwater detention during an extreme rainfall event, contributing to local flood resilience. 1

Key limitations or uncertainties

  • Performance evidence is based on event reporting rather than long-term quantitative monitoring
  • Flood mitigation benefits are context-specific and dependent on catchment-wide interventions
  • Ecological outcomes associated with wetland and riparian planting have not been formally monitored 1

Relevance to design practice

  • Public open space can be deliberately engineered to deliver flood storage while retaining everyday recreational use
  • Floodable landscapes require careful surface, drainage, and maintenance design to remain usable and publicly acceptable
  • Maximum benefit is achieved when site-scale flood detention is embedded within a coordinated catchment or neighbourhood-scale blue–green infrastructure programme

References

  1. Auckland Council. (2023). Rain drain: Northcote’s new stormwater infrastructure tested to the max. OurAuckland.
  2. Kāinga Ora – Homes and Communities. (2022). Opening of Te Ara Awataha greenway starting soon.
  3. Isthmus. (n.d.). Te Ara Awataha Greenway.
  4. Auckland Council. (2020). Green light for Greenslade Reserve upgrades. OurAuckland.