Pest control programme in the Hūnua Ranges

28 September 2018

Water supply dams back in service

Update: 18 October 2018

Following heavy rain on the night of 11 October, we have done further testing at all four dams. The tests have all come back clear, with no 1080 detected.

Update: 4 October 2018

We have returned our Wairoa and Mangatawhiri water supply dams to service after approval was given from the medical officer of health earlier today.

The dams had been out of service as a planned precautionary measure since before Auckland Council carried out its 1080 application on September 27.

Watercare has been regularly testing samples of water from multiple locations within each dam since the aerial application was implemented in the surrounding forest.

All samples returned results showing no sodium fluoroacetate (1080) was detected.

Final stage of pest control programme now complete

Update: 9am, Monday 1 October

We are carrying out extensive water quality testing after Auckland Council completed the final stage of its pest control programme on Thursday 27 September.

Wairoa dam water testing results

  Sample point 1 Sample point 2 Sample point 3 Sample point 4
Pre-1080 drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
4-8 hours after drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
20-24 hours after drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
40-48 hours after drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
After 11 October Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓


Mangatawhiri dam water testing results

  Sample point 1 Sample point 2 Sample point 3 Sample point 4
Pre-1080 drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
4-8 hours after drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
20-24 hours after drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
40-48 hours after drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
After 11 October Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓


Auckland Council to undertake final stage of pest control programme

Update: 9am, Thursday 27 September

Today, Auckland Council will undertake the third and final stage of its pest control operation in the Hūnua Ranges. This involves applying sodium fluoroacetate (1080) to a block of land surrounding Wairoa and Mangatawhiri water supply dams.

In preparation, we have taken these dams out of service. This means there is no risk to Aucklanders’ water supply. Once the application is complete, we will carry out extensive water quality testing and report the results on this page.

Last week, we took Cosseys and Mangatangi water supply dams out of service ahead of council carrying out the second stage of its application. Yesterday, the Auckland Regional Public Health Service completed its review of our extensive water sampling results – which showed 1080 was not detected in the dams – and approved their return to service.

Watercare to take dams out of service during Auckland Council’s pest control programme

Update: 9am, Monday 24 September

We are carrying out extensive water quality testing after Auckland Council completed the first stage of its pest control programme on Saturday 22 September.

Cosseys dam water testing results

  Sample point 1 Sample point 2 Sample point 3 Sample point 4
Pre-1080 drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
4-8 hours after drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
20-24 hours after drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
40-48 hours after drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
After 11 October Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓


Mangatangi dam water testing results

  Sample point 1 Sample point 2 Sample point 3 Sample point 4
Pre-1080 drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
4-8 hours after drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
20-24 hours after drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
40-48 hours after drop Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓
After 11 October Undetected ✓ Undetected ✓ Undetected ✓ Undetected ✓


Update: 4pm, Friday, 21 September

Auckland Council is intending to carry out the second stage of its pest control operation this weekend, weather permitting. This comes after they received the green light from the Environment Court.

The operation involves applying sodium fluoroacetate (1080) to a block of land surrounding Cosseys and Mangatangi water supply dams.

Our customers can be confident that their water supply will continue to be safe to drink.

We will take the water supply dams out of service before the operation begins and then carry out extensive water quality testing over several days. The results will be reported in the tables at the top of the page.

Our water sampling plan incorporates recommendations by Landcare Research and was approved by the Auckland Regional Public Health Service.

Testing will be carried out by Watercare Laboratory Services, an IANZ accredited lab with IANZ-approved test methodology for 1080. Water samples will also be tested at a second lab to provide further reassurance.

The Ministry of Health sets a Provisional Maximum Acceptable Value for 1080 of 0.0035mg/L for sodium fluoroacetate (1080). The Auckland Regional Public Health Service has set a maximum of 0.00175mg/L for drinking water.

We will only return our dams to services once the level of 1080 is below the detectable limit and approval has been given from the Medical Officer of Health.

Update: 4pm, Friday 14 September

Auckland Council has provided the following update on their pest control programme:

The council, joined by the Department of Conservation and other programme partners, presented evidence and made submissions to the Environment Court on 13 and 14 September in response to an application for an enforcement order to prevent the aerial Hunua pest management programme being carried out.

The court reserved its decision until next Friday (or sooner if the judge and commissioners are able to deliver their decision earlier than that). The temporary injunction that currently applies has been extended.

Any decisions about delivering the Hunua programme will be dependent on the court’s decision and, if in the council’s favour, the weather forecast. The right wind conditions and a fine weather window on either side of the bait application are required.

This update is available on the council’s website.

Update: 12pm, Thursday 6 September

Auckland Council is carrying out the first stage of its pest control operation today and tomorrow.

This involves applying non-toxic pre-feed bait to the entire operational area to get the pests used to eating the pellets. For more information, please visit the council website.

Watercare to take dams out of service during Auckland Council’s pest control programme

4 September 2018

Last week, Auckland Council announced that its second pest control operation involving the application of sodium fluoroacetate (1080) in the Hūnua Ranges and surrounding land was close to getting underway.

Watercare owns and operates four water supply dams in the Hūnua Ranges which provide 65 per cent of Auckland’s drinking water. To ensure our city’s drinking water remains safe, we will take the dams out of service during the council operation and carry out stringent water quality testing before they return to service.

The pest control operation will be carried out in three stages:

  1. A non-toxic pre-feed will be applied to the entire operational area to get the pests used to eating the pellets. 

  2. Sodium fluoroacetate (1080) will be applied to a block of land surrounding Cosseys and Mangatangi dams. These dams will be out of service until water quality testing is complete and the Medical Officer of Health is satisfied the drinking water is safe.

  3. Once Cosseys and Mangatangi dams are back in service, sodium fluoroacetate (1080) will be applied to a block of land surrounding Wairoa and Mangatawhiri dams. As with the previous application, these dams will be out of service until water quality testing is complete and the Medical Officer of Health is satisfied the drinking water is safe.

Watercare chief operations officer Shane Morgan says Aucklanders need not be concerned.

“We will report the results of the water quality testing on our website, so that the public can have full confidence in the measures we are taking to protect their health.”

A water sampling plan has been developed by Watercare using recommendations by Landcare Research and approved by the Auckland Regional Public Health Service.

Testing will be carried out by Watercare Laboratory Services, an IANZ accredited lab.

Water will be tested at four locations within each dam. These locations represent sites where the run-off from the catchment enters the dam.

Mr Morgan says even with two dams closed at a time, there is still enough water for all Aucklanders.

“Our other Hūnua dams, along with dams in the Waitākere Ranges, water from the Waikato River and various ground sources are capable of maintaining high quality supply at daily use levels.”

The council pest control operation is guided by the best practice use of 1080, set down by the government, and the conditions of permission granted to the council by the Auckland Regional Public Health Service (ARPHS).

Auckland Council says they are carrying out a well-planned, complex operation. They encourage people to read the information on the council’s website. Here you can find out more about the operation and the use of 1080, how it is being carried out and the safety measures in place.
 
 

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