Better late than never!
NIWA staff installing an automatic sediment recorder below the gates of the Oakden canal 29 March 2022
Just Checking
On returning from the Coast I made a diversion to see if Trustpower was diverting the Wilberforce flows into Lake Coleridge given the Rakaia River was running below the March minimum flow of 105 m3/sec.
Lake Coleridge was low and the Oakden canal was not flowing. Good.
NIWA
I took the opportunity to ask the NIWA crew what they were working on and was advised they were installing a sediment recorder in order that Ecan and Trustpower would be able to measure compliance with CRC consent CRC173073.
I was aware of previous CRC consents issued to ECNZ regarding the amount of sediment allowed to enter Lake Coleridge via the Harper River and Wilberforce River diversions.
According to the NIWA crew, it would not have been possible to measure the sediment without a device such as they were installing.
When I asked about the lack of flow in the Oakden canal I was informed that Trustpower’s digger driver is presently off work due to COVID.
When I asked if a similar device was planned for the Harper River diversion I received a look of amusement.
Harper River Diversion
The delta formed at the head of Lake Coleridge by the Harper River Diversion
The bridge over the Harper diversion has recently been replaced after the previous bridge was washed out. Evidence Trustpower had allowed a massive flood through this canal
Further Investigation required
Decades ago my father and I used to fish the junction of the Wilberforce and Rakaia Rivers while jet boating to the Hydra Waters confluence further upstream.
There were usually a few salmon waiting to run up the Wilberforce as well as some feisty rainbow trout in the lower Wilberforce pools.
CRC consent CRC172936 stipulates only 3 m3/sec of residual flow immediately downstream of Trustpower’s dams need be left in the Wilberforce River.
It seems likely such a low flow would be lost to groundwater before the downstream confluence with the Rakaia River?
If this were the case a significant number of returning adult salmon would be blocked from the upstream Wilberforce River tributaries.
Conversely if adult salmon could negotiate this stretch of the Wilberforce, are there fish screens to prevent the returning juveniles from being diverted into Lake Coleridge?
The Rakaia River NWCO
The NZFFA, NZ Salmon Anglers and other river advocates are waiting for a reply from a letter NZFFA sent to David Parker requesting a meeting to discuss Ecan’s apparent failure to give effect to the minimum flows proscribed in the amended Rakaia River NWCO 1988.
We will post an update when we get a reply.
Dr Peter Trolove
President NZFFA
[Some relevant CRC consents attached below]
CRC173082
|
Client Name
|
Trustpower Limited
|
Consent Location
|
Lake Coleridge Power Station, LAKE COLERIDGE
|
State
|
Issued - Active
|
To
|
to discharge water from the Harper Diversion Canal to Lake Coleridge at or about map reference K34:849-736
|
Commencement Date
|
24 Dec 1996
|
Date This Consent Number Issued
|
28 Oct 2016
|
Expiry Date
|
19 Dec 2031
|
Please note there has been a change to how we represent the date fields. The ‘Date This Consent Number Issued’ is the date this version of the consent was issued. The ‘Commencement Date’ is when the original version of this consent was issued as per s116 of the Resource Management Act 1991.
|
The maximum rate of discharge from the Harper Diversion Canal shall be 40 cumecs.
The consent holder shall maintain a record of when the diversion of water through the Harper Diversion is shut off and shall make such record available to the Canterbury Regional Council on request.
The cosnent holder shall carry out further delta surveys using the sites and methods used by R M Kirk and J C Allen as detailed in the Report W42 to the Lake Coleridge Working Party:
-
- at five year intervals and;
- one survey after an extreme natural event such as when the lake level exceeds the maximum operating level of 509.4 metres or is below the minimum ooperating level of 505.6 metres. The first survey under (i) above shall be undertaken within three years from the date of commencement of this consent. A report in writing on each survey shall be made to the Canterbury Regional Council.
- 4
The consent holder shall advise the North Canterbury Fish and Game Council as soon as is practicable of the intention to close the Harper Diversion Intake gates to facilitate the salvage of fish in the Harper Diversion Canal.
The consent holder shall take such measures as the Canterbury Regional Council may reasonably require to remedy or mitigate the effects of damage from erosion caused to property of other persons by the consent holders operations in the exercise of this consent.
The provisions of Section 125 of the Resource Management Act shall not apply until six years from the date of commencement of this consent.
If at any time, the consent holder does not exercise this consent for a continuous period of two years, the consent shall not be cancelled under Section 126 of the Resource Management Act 1991.
The Canterbury Regional Council may annually, on the last working day of June, serve notice of its intention to review the conditions of this consent for the purposes of:
-
- dealing with any adverse effect on the environment which may arise from the exercise of the consent and which is appropriate to deal with at a later stage; or
- requiring the adoption of the best practicable option to remove or reduce any adverse effect on the environment; or
- complying with the requirements of a relevant rule in an operative regional plan.
- 9
Charges, set in accordance with section 36 of the Resource Management Act 1991, shall be paid to the Regional Council for the carrying out of its functions in relation to the administration, monitoring and supervision of resource consents and for the carrying out of its functions under section 35 of the Act.
CRC172936
|
Client Name
|
Trustpower Limited
|
Consent Location
|
Lake Coleridge Power Station, WILBERFORCE RIVER
|
State
|
Issued - Active
|
To
|
to dam water in the Wilberforce River by means of a series of temporary gravel weirs/embankment at or about map reference K34:815-774
|
Commencement Date
|
24 Dec 1996
|
Date This Consent Number Issued
|
28 Oct 2016
|
Expiry Date
|
19 Dec 2031
|
Please note there has been a change to how we represent the date fields. The ‘Date This Consent Number Issued’ is the date this version of the consent was issued. The ‘Commencement Date’ is when the original version of this consent was issued as per s116 of the Resource Management Act 1991.
|
The consent holder shall maintain a surface flow of water in the Wilberforce immediately downstream of the diversion bank which by estimation shall not be less than three cumecs.
The consent holder shall take such measures as the Canterbury Regional Council may reasonably require to remedy or mitigate the effects of damage from erosion caused to property of other persons by the consent holders operations in the exercise of this consent.
The Canterbury Regional Council may annually, on the last working day of June, serve notice of its intention to review the conditions of this consent for the purposes of:
-
- dealing with any adverse effect on the environment which may arise from the exercise of the consent and which is appropriate to deal with at a later stage; or
- requiring the adoption of the best practicable option to remove or reduce any adverse effect on the environment; or
- complying with the requirements of a relevant rule in an operative regional plan.
- 4
Charges, set in accordance with section 36 of the Resource Management Act 1991, shall be paid to the Regional Council for the carrying out of its functions in relation to the administration, monitoring and supervision of resource consents and for the carrying out of its functions under section 35 of the Act.
CRC173073
|
Client Name
|
Trustpower Limited
|
Consent Location
|
Lake Coleridge Power Station, WILBERFORCE RIVER
|
State
|
Issued - Active
|
To
|
to discharge water from the Oakden Canal to Lake Coleridge at or about map reference K34:837-740
|
Commencement Date
|
24 Dec 1996
|
Date This Consent Number Issued
|
28 Oct 2016
|
Expiry Date
|
19 Dec 2031
|
Please note there has been a change to how we represent the date fields. The ‘Date This Consent Number Issued’ is the date this version of the consent was issued. The ‘Commencement Date’ is when the original version of this consent was issued as per s116 of the Resource Management Act 1991.
|
The maximum rate of discharge from the Oakden Canal shall be 50 cumecs.
When the suspended sediment content of the discharge to Lake Coleridge is likely to exceed 350 tonnes per day, the consent holder shall take immediate steps to cease the discharge until such time as the suspended sediment content of the discharge is unlikely to exceed 350 tonnes per day.
The consent holder shall maintain a record of when the diversion of water through the Wilberforce Diversion Canal is shut off and shall make such record available to the Canterbury Regional Council on request.
CRC173073
|
Client Name
|
Trustpower Limited
|
Consent Location
|
Lake Coleridge Power Station, WILBERFORCE RIVER
|
State
|
Issued - Active
|
To
|
to discharge water from the Oakden Canal to Lake Coleridge at or about map reference K34:837-740
|
Commencement Date
|
24 Dec 1996
|
Date This Consent Number Issued
|
28 Oct 2016
|
Expiry Date
|
19 Dec 2031
|
Please note there has been a change to how we represent the date fields. The ‘Date This Consent Number Issued’ is the date this version of the consent was issued. The ‘Commencement Date’ is when the original version of this consent was issued as per s116 of the Resource Management Act 1991.
|
The maximum rate of discharge from the Oakden Canal shall be 50 cumecs.
When the suspended sediment content of the discharge to Lake Coleridge is likely to exceed 350 tonnes per day, the consent holder shall take immediate steps to cease the discharge until such time as the suspended sediment content of the discharge is unlikely to exceed 350 tonnes per day.
The consent holder shall maintain a record of when the diversion of water through the Wilberforce Diversion Canal is shut off and shall make such record available to the Canterbury Regional Council on request.
The consent holder shall continuously measure and record the levels of turbidity of the water in the Oakden Canal except when the diversion is shut off.
The consent holder shall, for a period of five years from the date of commencement of this consent:
-
- undertake at six-monthly intervals, surveys of the macrophyte communities of Lake Coleridge, in particular respect of species, abundance, cover and biomass estimates.
- undertake three surveys at two-yearly intervals at three selected sites and at two depths of macroinvertebrates in Lake Coleridge in particular respect of species and abundance
- continuously monitor the levels of water on Lake Coleridge using the Lake Coleridge datum as a reference
- undertake a creel survey every year
- measure and record samples of scales and otoliths from fish caught in the lake at the time the creel survey is carried out
- the consent holder shall supply such records and the results of surveys undertaken in an annual report to the Canterbury Regional Council
- the consent holder shall prepare a final report with a sumary and interpretation of the results of the surveys carried out under this condition and shall provide a copy of the report to the Canterbury Regional Council by 31 March 2002.
- 6
The consent holder shall measure the secchi depth of the lake water monthly at a mid-lake location.
The consent holder may apply for a change or cancellation of condition (6) of this consent at any time after five years from the date of commencement of this consent.
The Canterbury Regional Council may annually, on the last working day of June, serve notice of its intention to review the conditions of this consent for the purposes of:
-
- dealing with any adverse effect on the environment which may arise from the exercise of the consent and which is appropriate to deal with at a later stage; or
- requiring the adoption of the best practicable option to remove or reduce any adverse effect on the environment; or
- complying with the requirements of a relevant rule in an operative regional plan; or
- requiring a reduction in the suspended sediment content in the discharge to Lake Coleridge through the Oakden Canal; or
- extending or reviewing the period of the surveys required under conidtion (5) of this consent.
- 9
Charges, set in accordance with section 36 of the Resource Management Act 1991, shall be paid to the Regional Council for the carrying out of its functions in relation to the administration, monitoring and supervision of resource consents and for the carrying out of its functions under section 35 of the Act.
The consent holder shall, for a period of five years from the date of commencement of this consent:
-
- undertake at six-monthly intervals, surveys of the macrophyte communities of Lake Coleridge, in particular respect of species, abundance, cover and biomass estimates.
- undertake three surveys at two-yearly intervals at three selected sites and at two depths of macroinvertebrates in Lake Coleridge in particular respect of species and abundance
- continuously monitor the levels of water on Lake Coleridge using the Lake Coleridge datum as a reference
- undertake a creel survey every year
- measure and record samples of scales and otoliths from fish caught in the lake at the time the creel survey is carried out
- the consent holder shall supply such records and the results of surveys undertaken in an annual report to the Canterbury Regional Council
- the consent holder shall prepare a final report with a sumary and interpretation of the results of the surveys carried out under this condition and shall provide a copy of the report to the Canterbury Regional Council by 31 March 2002.
- 6
The consent holder shall measure the secchi depth of the lake water monthly at a mid-lake location.
The consent holder may apply for a change or cancellation of condition (6) of this consent at any time after five years from the date of commencement of this consent.
The Canterbury Regional Council may annually, on the last working day of June, serve notice of its intention to review the conditions of this consent for the purposes of:
-
- dealing with any adverse effect on the environment which may arise from the exercise of the consent and which is appropriate to deal with at a later stage; or
- requiring the adoption of the best practicable option to remove or reduce any adverse effect on the environment; or
- complying with the requirements of a relevant rule in an operative regional plan; or
- requiring a reduction in the suspended sediment content in the discharge to Lake Coleridge through the Oakden Canal; or
- extending or reviewing the period of the surveys required under conidtion (5) of this consent.
- 9
Charges, set in accordance with section 36 of the Resource Management Act 1991, shall be paid to the Regional Council for the carrying out of its functions in relation to the administration, monitoring and supervision of resource consents and for the carrying out of its functions under section 35 of the Act. |