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Lake front? Passive recreation? Pools of snot?

Updated: Nov 2

By Pauline Stewart.

Background: This is about the lakes or ponds at Cooks Beach. They are fresh water but an eye sore and a health hazard. Diquat gel has been used by the council for 20 years to clear the lakes of exotic weeds and the green slime. It acts as a desiccant. That means the structure of the weed gets broken down. It can’t photo synthesise and so leaves drop to the bottom. The plant doesn’t die at all, just the top leaves drop off. Everyone thinks this is terrible stuff, but the di quart gel has been approved. It is sprayed with a backpack. It hits the water, spreads out and then sinks. When the water level drops, it doesn’t kill the weeds, and we are trying to kill those weeds. They drop away out of sight, that means out of mind, but it comes back with a vengeance when the summer comes.

The Council decided not to do any more spraying because it wasn’t working. (It worked only temporarily three or four months of the year). When the lakes were established, they were intended as a storm water retention system which seems to work well. When the developers did the sub-division, the lakes/ponds were marketed as ‘lake front’. They are now called ‘passive recreation’ on the Council plan of the area. One resident rang The Informer to describe the lakes as ‘descending into pools of snot.’

First stage of Community Board/Council process July 2022

When the Council stopped doing the spraying, a representative group we will call the Cooks Beach team (CB) went to the Council. They had an option in mind and another option had been mentioned by the Council. The Cooks Beach team had thoroughly researched their option (Second Option).

Option One: Mechanical harvesting was the option mentioned by the Council - a bit like mowing lawns – got to keep doing that. The cost of this is prohibitive and this would have discouraged the Council.

Option Two: Proposed by CB team – Grass (silver) carp as a weed control measure (not Koi Carp).

Their submission was made last July 2022. The then Community Board and Councillors whole heartedly accepted the report and as a result, it was recommended to TCDC staff that they investigate the use of Grass(silver) Carp - the option proposed by the CB action group. This meant the commissioning of a report by a consulting company in Auckland, who were reputedly experts in the field of freshwater lake contamination and the matter of grass (silver) carp. This study commenced on 22 October, the same month as a newly elected TCDC and Mercury Bay Community Board began their term of service.

The CB group made enquiries, but there was no further communication, except the local CB representatives were promised by Council that they would receive a copy of the report. Finally in August 2023 the report came – just two months ago.

Between October 22 and end of summer, given what had happened over the summer with cyclones and storms, the CB action group backed off putting pressure on Council, as they were very busy coping with storm damage. All that time, the weeds came and went, depending on how high the lake level was.

The level has been higher than average, but the residents know the weed is still there and the green surface reveals that.

There is a radio-controlled yacht club that uses the lakes, and it is an interest and activity the residents are keen to keep. Children and families love to kayak on the lakes. That would be too much of a health hazard now.

Back to the weeds – the issue is serious and needs to be addressed.

A group of residents have taken things into their own hands to save complete stagnation and actually did a partial clean out of one section of the lakes. On enquiry, they had pulled out two tons of weed by developing a kind of steel bar rake with a hook. It was jokingly suggested to talk to the Council about using this system. It is labour intensive and costly.

Puzzling note: What the residents refer to as weed that needs controlling, is referred to by specific councillors as containing some ‘native plants.’ However, there are often a lot of weeds that are not native.

Second stage of Council process: Community Board meeting 6 September.

The consultant’s report had arrived in August. A presentation by two CB representatives on 6 September 2023 was a five-minute presentation in the public forum segment. At 10.00am, Greg Roche and Brett Houston, Waterways Manager, came into the meeting and presented the consultant’s report to Council (the one that had been commissioned by the then Community Board in October 2022).

The Cooks Beach presenters were allowed to sit and listen to the presentation of the Consultants’ report, but they were not allowed to speak or comment.

In their words the report had the effect of ‘killing an ant with a sledge hammer.’

There was huge disappointment and frustration as a result of this report and the long period of waiting a hearing nothing.


A) It took a year and the report seemed to go in a totally misinformed direction. (This has been admitted to some extent by Greg Roche of TCDC)

B) The only reference to grass (silver) Carp, which was the main reason for the commissioned report, was a half-page on page 50 of the report and it was the wrong kind of carp. Of course, Koi Carp are definitely an unwanted species, but the option put forward to clear the lakes was Grass (silver) Carp. Gray Jamieson, Director of NZ Waterways Restoration (NZWRA), and who is the only DOC and MPI approved supplier of the grass (Silver) Carp in New Zealand was not consulted. This seemed unbelievable to the Cooks Beach people as there had been no consultation with the one waterways restoration company that had been successful working with several NZ regional councils on the same problem at Cooks Beach with the same solution the Cooks beach (CB) team had recommended.

C) There was no glossary on the Consultant’s report to substantiate their ‘research.’ Parts were a direct cut and paste off the internet.

D) The cost of such a report seemed exorbitant and the cost has not yet been stated.

E) No comment or questions were allowed when the consultants’ report was being made. The CB team were grateful for the pertinent challenges through questions asked of the consultant by then Community Board member, Deli Connell. Most of these could not be answered adequately (remember the Cooks Beach representatives weren’t allowed to ask questions or comment). Before this, when the CB team knew the commissioned report was to be tabled, they asked if they could be present. They were denied by a TCDC Manager, but when the team challenged it through a TCDC councillor, they were given the right to attend - thus their 5-minute presentation came about. The fact that they were forbidden from commenting or asking questions on a matter where there was little experience and knowledge on the subject from the Community Board and Council belies common sense. Yet CB people live with the problem and take on the responsibility of keeping the ponds clean in the meantime.

Third Stage of the process, a step initiated by Cooks Beach at Cooks Beach

The CB team were clear on this point; they were not saying that Grass (silver) Carp are the only option, but they were asking the Council to seriously investigate it as an option. Their report did not do this and the Community Board with Councillors present adopting it was a mistake. There were so many red flags when the questioned asked could not be answered by Greg Roche and Brett Houston. To keep things moving and communication open, the team invited Gray Jamieson of NZWRA and TCDC representatives and staff to come to a meeting with local Cooks Beach residents. That meeting occurred at Cooks Beach on Friday 13 October.

Grey Jamieson spoke of Grass (Silver) Carp as very suitable and of successful situations in similar settings around NZ. About Grass (Silver) Carp: They are herbivores; eat the more nutritious leaves from the top down; do not breed; are saline sensitive so need keeping in with fences or they die in salt water if they escape; live a long time so are economical; do not eat the food source out or eat out the native plants. Mr Jamieson described how the carp transform these stagnated green slime pools by themselves.

Still no progress and summer is coming: It seemed like a successful meeting, and it was reported as such at the recent Community Board meeting.

However, an email by the CB team has been received from Council with the effect that there will be no more action at this time and that there is nothing to report. How is that positive?

A prompt email response from the CB team to this has resulted in. Deli Connell TCDC asking Brett Houston (staff) to include this matter of the Grass (Silver)Carp in the Cooks Beach local committee’s agenda that has recently been formed to look at flooding and stormwater issues with TCDC.

Editors note: The interminable processes often not instigated out of experience and wisdom, are good intentioned, but they cost the taxpayer too much, and they go on too long. The issues are treated in a circular manner, not really listening to the experience and knowledge of local people who face the situations every day and who are in touch daily with their issue. More open processes are needed as policy and operational matters are excluding the people who pay the bills. Submissions are not trusted if the current practices are not efficient and do not bear witness to listening to the residents and rate payers. Things simply take too much time and shut out the very people who initiate the matters and look for and pay for the resolution. There should not be two sides to matters such as this. The ratepayers and residents require a better service from the people they elect who actually are working on their behalf and the staff whose job it is to serve the directives of the elected members.

Caption: : Algae and weed/slime build up in the culvert joining the two lakes.

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