Wetlands have pros and cons
What are the implications of an artificial wetland on the park’s enjoyment and maintenance?
Large-scale wetlands often require fencing for safety and environmental protection, which significantly reduces public accessibility. Wetlands support biodiversity but generally do not allow for active recreation such as walking, running, or playing. In wet conditions, adjacent paths may become slippery, muddy or impassable.
From a maintenance standpoint, wetlands are expensive to manage over time. Issues such as invasive weeds in the water and on the land, sediment build-up, poor water quality leading to botulism in ducks, midges and mosquito control and pest management including rats, are pervasive and require ongoing resources. Without careful management, they become degraded and will pose health and aesthetic concerns for nearby residents and park users.
The concept picture shown here poses many questions, not least of which, is “will an artificial wetland of this size work?” Other questions follow:
Why was recreation not integrated into the original proposal?
What is the long-term viability of the proposed (very large) wetland?
Will an artificial wetland work in this location on top of fractured basalt rock, that drains and dries out especially in summer?
The existing pond, dries and drains each summer
Has Auckland Council fully assessed the operational and maintenance costs to ratepayers, including the artificial wetland and the rest of the land?
Has Council evaluated the long-term earnings and Net-Present Value of the golf course, including its lease, rates contribution and maintenance savings?
Has Council considered the broader economic, social, cultural, and community value that the golf course provides to the North Shore and greater Auckland?
Has Council considered the VALUE of existing and future trees, that will be lost in favour of a large wetland area?
The large wetland area takes up space where more trees could go. More holes means more trees and more habitats for birds and nature.
We know our course:
16 years of drainage work, means we know the water, the rock (basalt) and the soil
We know the course drains away, especially in summer, which is also why the course returns to usable condition even after heavy rains
We know that a large wetland will be problematic during dry periods
We know the 1m diameter concrete main trunk sewer pipe, that runs through the middle of the course is old (circ. 1960)
The soils are alluvial and contain gravels, sands, silt, clay and peat – no problem for a golf course – but a big problem if intended for two huge artificial mounds
It is likely that the vegetation that covered the park area originally, was like the native forest left on the other side of Northcote Road alongside the motorway now called Smith’s Bush. Much of Smith’s Bush is below the level of AF Thomas park, which suggests that AF Thomas Park was never a wetland, but much more likely forest.
The Existing Pond Area
The pond dries out during the summer months and requires constant management and maintenance
The following statement is an extract from Frank Tian’s very recent memo (Healthy Waters Operations Manager for the North Shore) on the operational considerations of both options in the recent Feasibility Report.
Key Statement in Frank’s memo:
“Generally speaking, from an operations perspective, our preferred approach is to maximise the dry detention for stormwater attenuation, similar to what council built at Sunnynook or Greenslade, due to the following considerations associated with the wetland:
Infection of invasive weeds (Alligator weeds were found upstream, Parrot Feather weeds were also found in North Shore),
Debris from the large contribution catchment,
Silt build up and removal,
Aquatic weed control
Stagnant and possibly smelly water issue during dry and hot summers
We note that the above-mentioned concerns are typical concerns for any proposed wetland, particularly large-scale wetlands.”
Tom Mansell’s statement around costs and mosquitoes: Takapuna Golf Course: Auckland Council confirms controversial flood prevention plan - NZ Herald
“Mansell said maintenance costs for the wetland will not be low. They need to control mosquitoes by keeping the water flowing, and maintain the flood-detention capacity to a high level.” (The quote is near the end of article).
Finally:
Note: Minutes of the June 2025 meeting of the Devonport-Takapuna Local Board Workshop note this issue has been raised.
“Raised concerns about mosquito issues at AF Thomas Park; staff advised options are being explored to mitigate this.”
Key points are that a large wetland will be:
artificial (inconsistent with what is already onsite)
costly to maintain, even more so if its required to be done to a high standard
stagnant, smelly, rats, midges, mosquitos, invasive weeds
a liability for Auckland Council to maintain (within a limited operational budget) which will lead to substantial future costs to refurbish
prone to sediment build-up.
