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Environment
and Community Committee
14 August 2018
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Update
on Weiti development and wider catchment issues
File No.: CP2018/14420
Te take mō te pūrongo / Purpose of the report
1. To
update the committee on the Weiti development and surrounds as well as to
provide some facts and information in response to the presentation to the July
committee by the Great Parks Society on 10 July 2018.
Whakarāpopototanga matua / Executive summary
2. There
is a long planning history in the Okura/Weiti area, dating back over a decade
to legacy Rodney District Council. For Weiti, the existing planning
provisions have been approved through the Environment Court and consents have
been issued in accordance with these provisions.
3. The
catchment drains into Karepiro Bay and the Long Bay-Okura
marine reserve. There are a variety of land uses, including forestry,
agriculture and industry and numerous streams running through these uses.
Due to the nature of soils in the area, and around most of Auckland, there will
always be some sediment run-off from the land into the coast, regardless of
land use.
4. Council
is developing a land-based model and a coast-based (hydrodynamic) model to
better understand the long-term effects of land use on the coast. These models
have the potential to be used throughout Auckland in the future.
5. In
their presentation to the July Environment and Community Committee, the Great
Parks Society raised a number of concerns around the Weiti development and
council’s regulatory role. The report provides some brief facts in
relation to:
· Compliance
of the Weiti development with earthworks and sediment conditions
· Cockle
mortality
· Sediment
from smaller sites
· Weiti
Development’s environmental monitoring reports
· The
ability to ‘shut down’ earthworks activities.
6. In
summary, staff are satisfied that that the
erosion and sediment controls at this location are achieving high levels of
effectiveness, that the erosion and sediment control conditions are being met and the adverse effects on the environment are consistent with that
envisaged through the resource consents. There are no legal grounds to
cancel or review any existing consent.
7. At
a regional level, staff have been working across disciplines and departments to
consider possible alternative approaches to reducing sediment flow into
Auckland’s coastal environments, and it is recommended that we formally
report options to the committee by the end of the calendar year.
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Ngā tūtohunga / Recommendation/s
That the Environment and
Community Committee:
a) request
a scoping report by December 2018 on options for an integrated approach
to reduce sedimentation of Auckland’s coastal waters (a regional
view, not specific to the Weiti development or the catchment), including the
following matters:
i) individual
site approaches
ii) catchment
approaches
iii) timeframe
iv) costs
v) resourcing,
including any trade-offs in work programme required to prioritise this work.
b) note
that the land-based contaminant load and coastal modelling for the
Okura/Weiti catchment will be finalised by the end of 2018.
c) note
that as the bulk earthworks on the Weiti development draw to a close,
council’s compliance monitoring staff will continue to prioritise
monitoring of the development, particularly through the individual house-building
phases.
d) request
staff to continue to work with interested parties in the Okura/Weiti area
around on-going environmental modelling in the catchment.
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Horopaki / Context
Wider catchment
8. The catchment area that ultimately drains into Karepiro Bay and the
Long Bay-Okura marine reserve is a complex and varying environment. The total
area of the catchment is approximately 7,200 hectares and contains a variety of
land uses including forestry, agriculture, residential housing, commercial and
industrial activities. There are also a number of streams running through
the catchment and through all these land uses which then flow down into the
coast.
9. All land use, including grassed paddocks, affects the coastal
receiving environments and this has been demonstrated by the increase in fine
sediment that has been recorded in the eight east-coast estuaries council
monitors across the region. The soils in the catchment and around most of
Auckland are clay-based and not particularly porous, therefore there will
always be some sediment run-off from the land into the coast.
10. The
Long Bay Okura Marine Reserve was established in 1995 through an Order of
Parliament (the Marine Reserve (Long Bay-Okura) Order 1995), and covers all of
the Okura Estuary, parts of Karepiro Bay and the coastal waters past Long Bay
to Toria Point in the south. The reserve comprises a diversity of coastal habitats; the sandy beaches
of Long Bay and Karepiro Bay, the rocky reefs off the two headlands at either
end of Long Bay, and the sandflats and mudflats of the Okura River and
estuary. Figure 1 is a map showing the extent of
the Marine Reserve.
Figure 1 – Long Bay-Okura marine reserve
Planning history of Weiti
11. Planning controls have always sought to consider and recognise the
sensitivity of the receiving environment when planning decisions are
made. Both the Weiti and Long Bay developments have been considered
through the Environment Court process.
12. Rodney District Council (RDC) incorporated into
its District Plan provisions that allowed for the clustering of up to 550
dwellings at Weiti. RDC derived that figure by combining the number of
dwellings that could have been developed as of right under a surrounding Rodney
rural zone (Countryside Living Rural) in its 1993 District Plan (that being 400
dwellings), plus 150 dwellings that were already provided for under RDC Special
8 Zone.
13. It was considered that clustering the 550
dwellings would have a lower impact at Weiti and on the surrounding receiving
environment than the provision of 550 dwellings on countryside living lots
spread across the whole of the Weiti land.
14. All these provisions (including a limit of 550 dwellings) were
carried over into the Auckland Unitary Plan.
Tātaritanga me ngā tohutohu / Analysis and advice
Weiti – what council is doing
15. There are
three main elements to council’s work in this area – long term
monitoring, scientific modelling of the contaminant load (from current and
predicted land uses which provides inputs to a coastal-processes model that
subsequently describes the fate of these contaminants in the near-shore coastal
zone), and the monitoring of the Weiti development.
State of Our Environment modelling
16. Auckland Council, and previous Councils, have been monitoring the
health of the ecological communities on intertidal mud and sandflats within the
Okura Estuary since 2000 to try to understand the effects of land use over
time. A further seven small east coast estuaries are also monitored by Auckland
Council. Monitoring is carried out twice a year at four sites within each
estuary. In Okura, council monitors ten sites in recognition of the changing
land uses in the catchment.
17. Subtidal reef
ecology has been monitored in the reserve (Long Bay area) and nearby coastal
locations since 1999. Intertidal reef ecology was monitored by Auckland Council
in 2013 and will be repeating this next year. There has been other intertidal
reef monitoring by the Department of Conservation. Contaminants in sediment
have been monitored in the lower parts of Vaughans and Awaruku Streams since
1999 and on the Long Bay beach since 1998.
Land-based contaminant load (sources) and coastal (fate) modelling
18. A dynamic contaminant load model will characterise the load of
sediment, copper and zinc coming off the land as defined by the various land
uses undertaken within the catchment. This will provide inputs as loads to the
coastal hydrodynamic model. This coastal modelling is supported by the
deployment of water quality buoys that provide finer resolution continuous data
on currents, waves, sediment deposition rates and a number of other water
quality parameters. This data will be used to model sediment transportation
throughout the Okura and Weiti Estuaries, Karepiro Bay and the entirety of the
Long Bay-Okura Marine Reserve. This modelling will provide a better
understanding of the fate of sediment and the urban-derived metals copper and
zinc being discharged into the coastal receiving environment. The combination
of the land-based model and this hydrodynamic model will help to understand the
movement and sources of contaminants from these catchments.
19. Council staff
offered the opportunity for local developers, iwi and the Great Parks Society
to assist with both the land-based
contaminant load model scenarios and the coastal modelling approach. To
date, Williams Land Ltd has contributed and staff have met with representatives
of the Long Bay Okura Great Parks Society. Most field data has already
been collected and consultants are starting to assess possible land use
scenarios so that sedimentation effects can be modelled under changing
circumstances.
20. The hydrodynamic model is being developed primarily for the purpose
of assessing the long-term effects of different land use scenarios of the
catchment. However, the calibrated hydrodynamic model may also be used to
better understand the fate of sediment discharged during the earthworks phase
of development, from any given point within the coastal model’s
boundaries, and this approach can be applied to other receiving environments in
the Auckland area. This model is due to be completed by the end of the calendar
year.
Monitoring of Weiti development
21. In relation to the Weiti development, senior
earthworks specialists have been monitoring the bulk earthworks over the past
few years. The Weiti development is a high priority site in terms of
monitoring and is one of the most intensely monitored sites in the region with
regularly fortnightly monitoring by council. The developer has
voluntarily contracted independent experts to monitor the site in the alternate
weeks. The monitoring of this site has shown that the erosion and
sediment controls at this location are achieving high levels of effectiveness
and that the erosion and sediment control conditions are being met.
22. It is important to note that these conditions
are designed to perform during normal weather patterns, however, during extreme
weather events discharge of some sediment will occur. In recognition of
this, Adaptive Environmental Monitoring and Management Response Plans are
required to be sent to council following a trigger event of significant
rainfall (greater than 25mm in a 24-hour period and/or
15mm within 1 hour). To date Auckland Council
have received 38 trigger event reports. These reports have not identified any
areas of significant concern, any identified remedial action has been
undertaken quickly and staff remain satisfied that the erosion and sediment
controls are achieving a high level of effectiveness.
23. The aerial photos shown in the public forum
presentation of a plume of sedimentation discharging into the marine reserve is
a typical occurrence along Auckland’s coastline as a result of
significant rainfall. While urban development and earthworks may be a
contributing factor, there is currently no evidence that the level of
sedimentation observed in a significant rainfall around Okura/Weiti is any more
or less typical to the rest of Auckland’s coastline.
Response to some of the matters presented by the Great Parks
Society
24. Staff wish to
provide some facts and information in relation to the matters presented to the
Committee by the Great Parks Society in public forum on 10 July 2018.
Compliance of Weiti development with earthworks and
sediment conditions
25. In the presentation it was alleged that there have been high levels
of non-compliance at various sites surrounding the Long Bay-Okura Marine
Reserve. This included a claim that the Weiti site had a non-compliance
level of 75% from late 2015. This figure had been derived by considering
all scores of “2”, “3” or “4” in compliance
inspection reports as non-compliance and therefore resulting in adverse effects
on the environment.
26. Council’s compliance monitoring team uses a 1-4 scoring model
defined as follows:
· 1 = fully compliant;
· 2 = minor non-compliance where there is evidence of or potential for
no more than minor effects on the environment;
· 3 = more than minor non-compliance where there is evidence of or
potential for more than minor effects on the environment; and
· 4 = significant effect on the environment.
27. The score given during any particular compliance inspection is not a
site average but the highest score of any one of the erosion and sediment
control devices that were inspected. At its peak there were around 35
devices and 10 kilometres of silt fence that were in use at the Weiti
development. This meant that if there was a small maintenance issue identified
in any of those devices or with the silt fence, the overall score for that
inspection would be scored as a ‘2’ (minor non-compliance where
there is evidence of or potential for no more than minor effects on the
environment). In addition, a score of 2 is often issued when preventative or
maintenance issues have been identified to ensure environmental harm does not
occur in the future. Therefore, in such a case, there may have been no
adverse effects on the environment and the score of 2 is to avoid any
such effects in the future.
28. Therefore, staff do not consider a score of 2 to indicate any
adverse effects on the environment that are beyond that expected under the
resource consent. Of the 110 inspection reports for Weiti Development,
107 had a score of 1 or 2. For the 3 occasions where a 3 was scored, the
developer mitigated the issues in a timely manner that ensured minimal impact
on the receiving environment. Staff remain satisfied with the
compliance of the Weiti development and the adverse effects on the environment
are consistent with that envisaged through the resource consents.
Cockle mortality
29. A die-off of large numbers of cockles in the Okura estuary was
reported in April 2018. Samples were sent to the Ministry for Primary
Industries (MPI) for testing and investigation in April and May. The results
from both samples sent for testing were inconclusive and unable to pinpoint a
primary cause. The pathology identified a degree of environmental stress which
could be due to a number of variables such as high sediment during a rainfall
event, sustained high water temperatures or exposure to high temperatures
during low tide. Without samples from other locations there is no context for
whether this degree of environmental stress is present in other
estuaries. Internationally and nationally, these types of mortality
events are typically multi-factorial with interactions between a number of
stressors. Monitoring of mortality by the Department of Conservation has
confirmed that the mortality has not been ongoing.
30. MPI also advised that there have been increased shellfish
mortalities reported throughout the country this summer, including in the
Whangateau estuary.
Sediment from smaller sites
31. Staff agree that small sites do generate sediment and the cumulative
effect of this can be significant if not managed properly. These small
sites must all comply with erosion and sediment control provisions set out in
the Auckland Unitary Plan and/or any conditions of their resource
consent. Council has put considerable effort into ensuring small sites
are managed in a compliant manner. This includes the production of the
“Building on small sites” booklet which is printed in English and
Mandarin and the “Building on small sites” series of videos that
also include Mandarin subtitles. Council is also continuing to develop
targeted compliance programmes that focus on large scale small site programmes.
Weiti Development’s Environmental
Monitoring Reports
32. Council staff accept and agree with the methodology, analysis and
conclusions of Boffa Miskell, MPS and Ridley Dunphy in their various
environmental reporting of the site for Weiti Development.
“Shut down” earthworks activities
33. The Weiti
development is proceeding in accordance with resource consent and Auckland
Unitary Plan provisions. There is no evidence of adverse environmental
effects greater than anticipated by those provisions. Therefore, there
are no legal grounds to cancel any consent, review conditions or impose
different conditions under either the Auckland Unitary Plan or the Resource
Management Act 1991.
Ngā whakaaweawe ā-rohe me ngā tirohanga a te
poari ā-rohe /
Local impacts and local board views
34. The Chair of
the Hibiscus and Bays Local Board spoke in support of the Great Parks Society
at the Environment and Community Committee in July. The Great Parks Society
represents some members of the community who are concerned about the adverse
environmental effects of development on the marine reserve.
35. This report
is an update on existing development and relates to consents and planning
provisions approved over decades by the Environment Court and council.
There are no specific local impacts as a result of this report but any future
provisions may have a local impact.
Tauākī whakaaweawe Māori / Māori impact
statement
36. The mauri of
water is of critical importance to Māori. At a higher level, council
will include and consider Māori dimensions in any work that is done around
improving Auckland’s water quality.
37. In relation
to this report, given that it is an update on existing development as it
relates to already approved consents and Unitary Plan provisions, there is no
specific impact on Māori. However, it may be that on-going work
coming from this report will have direct impact on Māori and they will be
asked to be part of any such work.
Ngā ritenga ā-pūtea / Financial implications
38. There are no
financial implications as a result of this report. However, should the
Committee request scoping work to be done, this will include the likely
financial cost of any options. Any future work is unlikely to be fully
budgeted and will likely require a re-prioritisation of other work. If
this is the case, it will be included in the next report to Committee.
Ngā raru tūpono / Risks
39. The
recommendations of the report focus on finalising the modelling, continuing
with a high level of monitoring of development sites, as well as scoping
options for a possible review of existing provisions and guidance documents
around sedimentation. There are no significant risks related to the
proposed recommendations. The main risk with these recommendations
relates to work programme – the scoping work will take internal resource
which would otherwise be spent on other work and there is a risk that the
delivery of other work may be delayed.
Ngā koringa ā-muri / Next steps
40. The quality
of water and the greater environment is a key focus of this council through the
Auckland Plan 2050 and the Long-term Plan 2018-28. The question is
whether or not the existing conditions and controls normally imposed on land
uses requiring consent for earthwork activities are “good enough”
when it comes to the impact on the environment and the long-term health of
ecosystems? In view of this, there are a number of actions that can be
taken:
· Council staff will continue with the monitoring regime of the
remaining bulk earthworks and small sites of the Weiti development to ensure
compliance with resource consents and the Auckland Unitary Plan;
· Council
will continue to reach out to interested parties for involvement in the long
term monitoring and modelling of the catchment;
· Council will continue to work with the Hauraki Gulf Forum and the
other agencies to improve the health of the Hauraki Gulf;
· Council will continue to defend the location of Rural Urban Boundary
throughout the region, including in Okura, in recognition of its role in
protecting the sensitive receiving environment that surrounds it;
· The forthcoming Enhancements Plan Change to the Auckland Unitary
Plan will include reference to the updated Guidance for Erosion and Sediment
Control (GD05) for Land Disturbing Activities. This updated guidance includes
the “protection of receiving environments, including sensitive receiving
environments” within the fundamental principles of erosion and sediment
control, makes explicit reference to the impacts of climate change on weather
patterns and refers developers to best practice guidance within the Small Sites
booklet in English and Mandarin; and
· Staff
will continue to work across disciplines and departments to identify
alternative approaches and solutions to sedimentation. Should the
Committee wish to consider this matter more formally, staff will need to scope
this and come back to the Committee with advice about timing, cost and
potential work programme trade-offs.
Ngā
tāpirihanga / Attachments
There are no attachments for
this report.
Ngā kaihaina / Signatories
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Author
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Megan Tyler – Acting General Manager Licensing
and Regulatory
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Authoriser
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Dean Kimpton - Chief Operating Officer
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