21 February 2023
Cher Ryker
Via email
Email
: [FYI request #21805 email]
Dear Cher
REQUEST FOR INFORMATION UNDER THE LOCAL GOVERNMENT OFFICIAL INFORMATION AND MEETINGS
ACT 1987 (LGOIMA) – AUCKLAND COUNCIL’S HŪNUA RANGES PEST CONTROL OPERATION DURING
AUCKLAND FLOODING
Your request
Thank you for your online enquiry, dated 12 February 2023, expressing your concerns around Auckland
Council’s Hūnua Ranges pest control operation during Auckland flooding.
For ease of reference, I capture your enquiry here.
“I would like to have all the information and data and response that you have about the impacts of
the 1080 depositing on the Hunua ranges in 2022 and the flooding of Auckland 2023,what are the
effects that can cause harm towards humans, animals and the Water supply ? I I also would like all
data report including site locations, maintenance and operations taken out between the 23/01/23
and 29/01/23”
As requested in your email, we have constituted your online enquiry as a LGOIMA request under the Local
Government Official Information and Meetings Act 1987.
Our response
We answer the first part of your question below regarding the 1080 operation in 2022.
Background
First of all, we would like to inform you that the pest control operations in the Hūnua Ranges are
undertaken by Auckland Council. During these pest control operations, Watercare’s role is to protect the
water supply. How we do this is explained below.
Pest Free Auckland is Auckland Council’s targeted programme to control pest animals and plants across
Tāmaki Makaurau. Auckland Council provides advice, support and community education on the threats and
control of pests – se
e Pest plants and animals for more information.
In 2015, Auckland Council aerially applied 1080 (sodium fluoroacetate) to approximately 21,500 hectares of
parkland and private land in the Hūnua Ranges area. A few months after the last application, monitoring
results showed the lowest recorded figures for rats and possums. There was zero percent found in the
kōkako management areas.
A similar operation was conducted in Hūnua in August/September 2018.
2022 pest control operation
Between August and November 2022, Auckland Council conducted another application of 1080 bait the
Hūnua Ranges area. This was done in three stages:
1. A non-toxic pre-feed is applied to the entire operational area to get the pests used to eating pellets.
2. Sodium fluoroacetate (1080) was then applied to a block of land surrounding Cosseys and Mangatangi
dams. These dams are taken out of service until water quality testing was complete and the Medical
Officer of Health was satisfied the drinking water was safe.
3. Once Cosseys and Mangatangi dams were back in service, sodium fluoroacetate (1080) was applied to a
block of land surrounding the remaining two dams in the Hūnua Ranges, namely Wairoa and
Mangatawhiri dams. As with the first application, these dams remained out of service until water
quality testing was complete and the Medical Officer of Health was satisfied the drinking water was
safe.
Role of Watercare
As Auckland Council’s pest control operations occur in water catchment areas, they require careful
planning. We can assure you that Watercare worked closely with Auckland Council to ensure the ongoing
safety of Auckland’s water supply, including:
• Ensuring that the helicopters do not fly over water supply reservoirs when carrying bait
• Ensuring there are also exclusion zones around reservoirs where no bait will be applied
• Using accurate (GPS) technology to apply the bait
• Suspending the reservoirs before the operation and only returning them to service after rigorous water
testing confirms there is no 1080 detected in the water
• Working with landowners to understand what streams they use for drinking water that flow out of the
operational area
• Keeping a close watch on the weather forecast to determine the optimal weather 'window' for the
operation.
Our water sampling plan
We developed our sampling plan using recommendations from Landcare Research and our plan was
approved by the Auckland Regional Public Health Service.
All testing results were recorded publicly on ou
r website, and we did not put our Hūnua dams back in
service until all samples show there were no 1080 detected in the water.
Testing was being carried out by Watercare Laboratory Services, an IANZ accredited lab. Duplicate samples
were flown to Christchurch and hand delivered to the Landcare Laboratory. This ensured the quickest
possible analysis of the duplicate samples.
In 2022, all results showed either below the detection limit or ‘undetected’ results.
Even with two of the four Hūnua dams closed at a time, there was still plenty of water to meet Auckland’s
needs. The diversity of our water sources – with dams in the Waitākere Ranges, water from the Waikato
River and groundwater supplies – means we continued to safely treat enough drinking water for our
customers while the pest control operation was carried out by Auckland Council.
Watercare takes very careful steps to ensure all the drinking water we supply (even during and after pest
control operations) presents no risk to public health. Indeed, we supply safe, reliable drinking water to our
Auckland customers 24/7, every day of the year.
We seek clarification of the second part of your question
We understand that the second part of your question is as follows:
“I would like to have all the information and data and response that you have about the impacts of the
flooding of Auckland 2023, what are the effects that can cause harm towards humans, animals and the
Water supply ?
I also would like all data report including site locations, maintenance and operations taken out between the
23/01/23 and 29/01/23”
Your request as currently framed will be very difficult to meet without substantial collation or research as
you have requested every piece of information held by Watercare regarding the recent floods.
Unless your request is amended, we may have to refuse it under section 17(f) of the LGOIMA, which applies
where the information cannot be made available without substantial collation or research.
To enable us to meet our statutory obligation to make and communicate our decision on your request,
please let us know
by 28 February 2023 whether you wish to narrow down your request. If you narrow
your request, this will be considered to be a new request for the purpose of calculating the maximum
statutory timeframe for response section 13(7) of the LGOIMA.
Further options
You have the right to seek an investigation and review by the Ombudsman of this response. Information
about how to make a complaint is available at www.ombudsman.parliament.nz or freephone 0800 802
602.
Yours sincerely
Andrew Mercer
Acting Chief Operations Officer
