Lakes
Steve Lloyd has just written this letter regarding the dire condition of our lakes. Please take a wander around our lakes to see for yourself the algae bloom starving the waterways wildlife. Action needs to be taken.
Good afternoon Aileen,
I'm a committee member of the Cooks Beach Residents and Ratepayers Association where the question of the lake condition has been discussed at every committee meeting recently.
The concerns below were raised again at our AGM on 2nd January ‘24 at which the Mayor was present.
There is also a group of concerned and very frustrated residents who have been seeking Council's efforts to clean up the above waterways. The lakes are devoid of most bird life which succumb to the algal bloom now prevalent and the banks and water are littered with decaying, dead eels. Due to the current low water levels areas of the waterway are emitting foul smelling odours.
A brief background.
The residents group made a submission to the Community Board and councillors in July '22 for Council to consider the introduction of silver (grass) carp as a weed control measure. (Not to be confused with Koi carp). This submission was accepted by the Community board and councillors at the time and subsequently referred to council staff for further investigation.
Staff reaction In October '22to this request was to engage the services of a so-called water quality expert who produced an 80 odd page report which has since been shown to contain numerous errors and lack of reference details. The upshot of the report was to recommend a riparian planting programme which could only be implemented in the upcoming LTP. There was little or no reference to the carp question except to say that the so-called expert didn't know the difference between grass and koi carp!
This report was only released publicly on 6 September '23, 11 months after being commissioned, despite being requested on numerous occasions.
We believe the lake contains the toxic variety of horsetail weed, and other exotic weeds despite the expert above advising council all the weed is native! I reported this to WRC who sent a representative out to confirm or otherwise but as yet nothing heard back from them.
In October '23 we arranged for the principal of NZ Waterways Restorations (NZWR) to visit Cooks Beach and meet with council staff as it was our feeling that staff had made little or no attempt to investigate carp as a weed control option. NZWR is the only organisation legally allowed to supply grass carp via DOC/MPI licensing protocols.
Attending that meeting was Heather Bruce, Greg Roche, and councillors Connell and Giri-Percival.
Any concerns re carp was well and truly covered by NZWR and we feel staff acknowledged they had learned a lot about grass carp.
However and not withstanding the above, nothing has happened and numerous unanswered calls to staff finally resulted in a dive company from Hamilton coming to inspect the lake for weed clearing. After inspecting the lake prior, the Dive company turned up on 13 Dec for a suction dredge clearing operation. The pumps lasted 2 minutes before being jammed up by the weed. That was the end of that attempt to clear the lake of weed.
Why was a company engaged to clear the lake having seen what was involved only to fail dismally! And at what cost to Council/ratepayers?
On 29th December’23 a group of disgruntled residents did a partial clean of the western end of the lake (shallower end) and worst weeded over area, as large chunks of algae was gathering and starting to form a bloom. This action was taken as there was no indication from Council as to what would happen next.
As residents began arriving for their Christmas holidays and the scale of weed over seen first hand, calls were made to the water services representative based in Thames , as Greg Roche was on leave. The concern was raised that if a child fell into the lake ,say from a kayak, he/she could easily get tangled in the weed and come to grief. This gentleman’s reaction to these calls was to erect “no swimming signs” on the back of a couple of park benches!
In conclusion we as a group ask you, why has there been no investigation of the use of grass carp by council staff, as this is by far the most cost effective method and can almost be considered as a one-off cost as the fish live for quite a few years? NB grass carp have low salinity tolerance and therefore need to be contained. They would not survive in a briny/salt water environment.
We feel that staff seem to be ideologically opposed to the introduction of grass carp for whatever reason, despite these fish being widely used by many councils around NZ (Tauranga being our nearest) and appear to come up with any method to avoid the use of grass carp.
Looking forward to your response.
Cheers
Steve Lloyd
Good afternoon Aileen,
I'm a committee member of the Cooks Beach Residents and Ratepayers Association where the question of the lake condition has been discussed at every committee meeting recently.
The concerns below were raised again at our AGM on 2nd January ‘24 at which the Mayor was present.
There is also a group of concerned and very frustrated residents who have been seeking Council's efforts to clean up the above waterways. The lakes are devoid of most bird life which succumb to the algal bloom now prevalent and the banks and water are littered with decaying, dead eels. Due to the current low water levels areas of the waterway are emitting foul smelling odours.
A brief background.
The residents group made a submission to the Community Board and councillors in July '22 for Council to consider the introduction of silver (grass) carp as a weed control measure. (Not to be confused with Koi carp). This submission was accepted by the Community board and councillors at the time and subsequently referred to council staff for further investigation.
Staff reaction In October '22to this request was to engage the services of a so-called water quality expert who produced an 80 odd page report which has since been shown to contain numerous errors and lack of reference details. The upshot of the report was to recommend a riparian planting programme which could only be implemented in the upcoming LTP. There was little or no reference to the carp question except to say that the so-called expert didn't know the difference between grass and koi carp!
This report was only released publicly on 6 September '23, 11 months after being commissioned, despite being requested on numerous occasions.
We believe the lake contains the toxic variety of horsetail weed, and other exotic weeds despite the expert above advising council all the weed is native! I reported this to WRC who sent a representative out to confirm or otherwise but as yet nothing heard back from them.
In October '23 we arranged for the principal of NZ Waterways Restorations (NZWR) to visit Cooks Beach and meet with council staff as it was our feeling that staff had made little or no attempt to investigate carp as a weed control option. NZWR is the only organisation legally allowed to supply grass carp via DOC/MPI licensing protocols.
Attending that meeting was Heather Bruce, Greg Roche, and councillors Connell and Giri-Percival.
Any concerns re carp was well and truly covered by NZWR and we feel staff acknowledged they had learned a lot about grass carp.
However and not withstanding the above, nothing has happened and numerous unanswered calls to staff finally resulted in a dive company from Hamilton coming to inspect the lake for weed clearing. After inspecting the lake prior, the Dive company turned up on 13 Dec for a suction dredge clearing operation. The pumps lasted 2 minutes before being jammed up by the weed. That was the end of that attempt to clear the lake of weed.
Why was a company engaged to clear the lake having seen what was involved only to fail dismally! And at what cost to Council/ratepayers?
On 29th December’23 a group of disgruntled residents did a partial clean of the western end of the lake (shallower end) and worst weeded over area, as large chunks of algae was gathering and starting to form a bloom. This action was taken as there was no indication from Council as to what would happen next.
As residents began arriving for their Christmas holidays and the scale of weed over seen first hand, calls were made to the water services representative based in Thames , as Greg Roche was on leave. The concern was raised that if a child fell into the lake ,say from a kayak, he/she could easily get tangled in the weed and come to grief. This gentleman’s reaction to these calls was to erect “no swimming signs” on the back of a couple of park benches!
In conclusion we as a group ask you, why has there been no investigation of the use of grass carp by council staff, as this is by far the most cost effective method and can almost be considered as a one-off cost as the fish live for quite a few years? NB grass carp have low salinity tolerance and therefore need to be contained. They would not survive in a briny/salt water environment.
We feel that staff seem to be ideologically opposed to the introduction of grass carp for whatever reason, despite these fish being widely used by many councils around NZ (Tauranga being our nearest) and appear to come up with any method to avoid the use of grass carp.
Looking forward to your response.
Cheers
Steve Lloyd
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Background: for about the last 20 years the weed control has been by way of aquatic spraying using diquat gel. Apart from the name diquat is a very user friendly spray acting as a desiccant. This causes breakdown of the leaf structure so that the weed is unable to photosynthesise and consequently sinks to the bottom composting over time. The root structure is not affected and dependent on water conditions the weed usually sprouts away in 3-4 months negating any effect of the spray. Council has determined (presumably) that for this reason the spray program has been discontinued.
Council employees have mentioned another weed control method and that is mechanical harvesting. This is an extremely expensive method of weed control, and would need to be done on a regular basis. To my understanding this has not gone anywhere possibly due to the high repetitive costs involved.
The third proposal was to stock the waterways with grass or silver carp as they are known. This was the subject of our proposal submitted to the Community Board in July 2022. We received a subsequent email from the Board acknowledging the potential benefits of the carp proposal and that this would be referred to Council staff for follow up/investigation. To date the only action we’re aware of was the appointment of a water quality scientist to inspect the waterway on behalf of the Council. That occurred mid October last year. Apart from a few “snippets” relating to the carp nothing in that report has been released to the public.
Background: grass carp are herbivores and should NOT be confused with koi carp. Although grass carp are considered a pest there are strict control protocols in place for their release.
Any potential release site is inspected by DOC and Council to determine possible effects on releasing into specific waterways. Should there be no issues then DOC and the fish supplier company apply for a licence from the MPI for a predetermined quantity of fish, depending on weed over levels. A management contract can be arranged to provide monitoring of the fish. EG if too many are put into the lake and they don’t thrive then numbers are reduced. Conversely if not enough fish are supplied then the numbers are boosted. These fish are known as “the cows of the ponds” as they graze rather than clean out a weed source.
Containment is an important factor in any release of grass carp. This regard DOC has a minimum agreed mesh size of 35mm for covering outlet drains and importantly to stop fish escaping. I personally spoke with Council staff pointing out where outlet streams and pipes needed to be meshed. These fish are highly salinity intolerant meaning if they got into the stream leading down to the outlet point towards Shakespeare cliff they will certainly not survive.
Cost: my cost estimate for Council spraying the Cooks Beach Lakes (4 hectares in area) as presented to the Community Board last year was conservatively $10,000 being an annual spray cost back then.
Cost of carp advised at that time was $8000 to supply 100 fish based on an estimated 25% weed over factor. As these fish live for a number of years then this cost can be considered as a one-off with future management monitoring numbers etc.
During my discussions with Council staff I urged him to make further enquiries to the fish supplying company VIZ, nzwaterways.co.nz Their website is really worth a visit. To my knowledge Council employees have made no attempt to obtain any information whatsoever from NZ Waterways Restorations despite being given the contacts. And despite these fish being placed in storm water ponds in and around Tauranga, and Hauraki district council staff have seemingly made no attempt to do an in depth due diligence. They are now widely supplied throughout NZ (refer their website) and I understand are now in the Pauanui lakes golf course ponds as a private release.
Council employees have mentioned another weed control method and that is mechanical harvesting. This is an extremely expensive method of weed control, and would need to be done on a regular basis. To my understanding this has not gone anywhere possibly due to the high repetitive costs involved.
The third proposal was to stock the waterways with grass or silver carp as they are known. This was the subject of our proposal submitted to the Community Board in July 2022. We received a subsequent email from the Board acknowledging the potential benefits of the carp proposal and that this would be referred to Council staff for follow up/investigation. To date the only action we’re aware of was the appointment of a water quality scientist to inspect the waterway on behalf of the Council. That occurred mid October last year. Apart from a few “snippets” relating to the carp nothing in that report has been released to the public.
Background: grass carp are herbivores and should NOT be confused with koi carp. Although grass carp are considered a pest there are strict control protocols in place for their release.
Any potential release site is inspected by DOC and Council to determine possible effects on releasing into specific waterways. Should there be no issues then DOC and the fish supplier company apply for a licence from the MPI for a predetermined quantity of fish, depending on weed over levels. A management contract can be arranged to provide monitoring of the fish. EG if too many are put into the lake and they don’t thrive then numbers are reduced. Conversely if not enough fish are supplied then the numbers are boosted. These fish are known as “the cows of the ponds” as they graze rather than clean out a weed source.
Containment is an important factor in any release of grass carp. This regard DOC has a minimum agreed mesh size of 35mm for covering outlet drains and importantly to stop fish escaping. I personally spoke with Council staff pointing out where outlet streams and pipes needed to be meshed. These fish are highly salinity intolerant meaning if they got into the stream leading down to the outlet point towards Shakespeare cliff they will certainly not survive.
Cost: my cost estimate for Council spraying the Cooks Beach Lakes (4 hectares in area) as presented to the Community Board last year was conservatively $10,000 being an annual spray cost back then.
Cost of carp advised at that time was $8000 to supply 100 fish based on an estimated 25% weed over factor. As these fish live for a number of years then this cost can be considered as a one-off with future management monitoring numbers etc.
During my discussions with Council staff I urged him to make further enquiries to the fish supplying company VIZ, nzwaterways.co.nz Their website is really worth a visit. To my knowledge Council employees have made no attempt to obtain any information whatsoever from NZ Waterways Restorations despite being given the contacts. And despite these fish being placed in storm water ponds in and around Tauranga, and Hauraki district council staff have seemingly made no attempt to do an in depth due diligence. They are now widely supplied throughout NZ (refer their website) and I understand are now in the Pauanui lakes golf course ponds as a private release.