New Brighton (New Brighton Road) residential red zone: Summary of Technical
Information as at October 2016
Area ID: 4
Purpose of this document
The following information provides a summary of the local environmental values, conditions and potential
hazards. The information has been gathered using the best available technical data held by a number of
agencies and organisations. It does not identify or assess land use options or the feasibility of land uses.
The information in this document is not, and should not be interpreted as, a pre-determination,
recommendation or decision about future use. No decisions regarding the future use of this land have
been made.
Overview of New Brighton (New Brighton Road) residential red zone (Area 4A)
Area 4A is approximately nine hectares in area and is a long narrow strip of land located along the north
side of New Brighton Road, separated from the Ōtākaro/Avon River by Cockayne Reserve. Cockayne
Reserve combines the characteristics of a naturalised wetland margin along the Ōtākaro/Avon River with
stormwater treatment and flood conveyance functions.
Area 4A is susceptible to a number of natural hazards, which can potentially occur either in isolation or
collectively, leading to a number of adverse cascading effects. The risk from many of these hazards will
increase over time due to the accelerating effects of sea level rise. Due to the area’s proximity to the
estuary edge there is considerable risk from lateral spreading.
Location Map
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Natural Environment and Cultural Setting and Features
Natural
Environment
The area is adjacent to the Ōtākaro/Avon River and Tributaries identified as Sites
of Ecological Significance (Site ID no. SES/LP/24) in Chapter 9 (Natural and Cultural
Heritage) Appendix 9.1.4.1 of the notified version of the proposed Christchurch
Replacement District Plan1. This site is significant because it 'supports At-Risk fish
species including their migration routes, and supports indigenous vegetation and
avifauna that is representative of the Low Plains Ecological District'.
The adjacent Ōtākaro/Avon River mainstem has a significant yellow flag iris (Iris
pseudacorus) infestation. This plant is a weed that forms dense tuberous mats
excluding native wetland plants, choking wetlands and waterways and may
degrade whitebait spawning areas. The plant is designated an “unwanted
organism” under the Biosecurity Act and is identified as a pest by ECan.
Waterways
This area has frontage to the Ōtākaro/Avon River, which is classified as a
Downstream River with a 30m setback2 under Chapter 6 (General Rules and
Procedures) of the notified version of proposed Christchurch Replacement District
Plan3. Christchurch City Council’s vision for the Ōtākaro/Avon River catchment is
set out in the following document:
http://ccc.govt.nz/assets/Documents/Environment/Water/Avon-River-CatchmentVision-and-Values.pdf
Another waterway (Cockayne Reserve Drain) is subject to minimum setback
requirements (refer to Chapter 6 of the notified version of the proposed
Christchurch Replacement District Plan)4.
Groundwater –
depth below surface
Median groundwater depth is typically between 0.7m and 1.3m below surface
level at present.
Median groundwater depth with 1m sea level rise is shallower than 0.5m, and is at
the ground surface for much of Area 4.
Coastal Marine Area
Area 4A is outside the Coastal Marine Area.
Public Facilities
No public facilities are mapped in this area.
1
The Independent Hearings Panel is yet to issue a decision on Chapter 9 hence the provisions and related maps are subject to change.
A consent is required from the Christchurch City Council to build, fill or excavate within these setbacks.
3 The Independent Hearings Panel is yet to issue a decision on Chapter 6 hence the provisions and related maps are subject to change.
4 A resource consent is required from the Christchurch City Council to fill, excavate or build within this setback. Furthermore, the Independent Hearings Panel is
yet to issue its decision on Chapter 6 hence the provisions and related maps are subject to change.
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Reserves
At its north-western end, Area 4 adjoins Bower Park, a local sports park (38,442m2)
classified as Open Space Community Parks Zone under the proposed Christchurch
Replacement District Plan.
On its southern boundary, Area 4 adjoins Cockayne Reserve, a local reserve
(59,431m2) which is within Site of Ecological Significance (SES/LP/24) in Chapter 9
(Natural and Cultural Heritage) Appendix 9.1.4.1 of the notified version of the
proposed Christchurch Replacement District Plan5.
While not immediately adjoining Area 4, Rawhiti Domain sits in close proximity to
the north east. It is zoned Open Space Community Parks and is a large sports park
(613,543m2) with a golf course.
Mana Whenua /
Ngāi Tahu Interests
This area is recognised to have strong cultural significance with the connection to
Ihutai and the former Māori Reserve. It is part of a wider Ngāi Tūāhuriri takiwā
area of interest.
There are several archaeological sites of Māori origin known in this area, including
a Māori midden recorded as M35/293. The former kāinga site of Ōruapaeroa is
also within close proximity to Area 4.
The whole of Area 4 falls within the culturally significant zone which extends from
the Ōtākaro/Avon River northwards and is also part of a wider Ngāi Tūāhuriri
takiwā area of interest.
Mana Whenua and Ngāi Tahu strongly recognise the relationship of this area with
Te Ao Tūroa (Natural Environment), ecological values and water. This area also has
significant Mahinga Kai values.
Archaeology and
Heritage
Chapter 9 (Natural and Cultural Heritage) of the notified version of the Proposed
Christchurch Replacement District Plan: No listed features.
New Zealand Archaeological Association: There are two listed archaeological sites
within the boundary of Area 4. One of these is a midden and the other is a burial
which is associated with an indicative Archaeological Area.
There are several archaeological sites of Māori origin known in the locality,
including a Māori midden recorded as M35/293. The former kāinga site of
Ōruapaeroa is also within close proximity to Area 4.
Accordingly, there is the potential for further items or sites of archaeological value
to be discovered.
Special or Other
Features
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The Bower Tavern is located within this area at the south end of Bower Avenue.
The Independent Hearings Panel is yet to issue a decision on Chapter 9 hence the provisions and related maps are subject to change.
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Hazards
Coastal Hazard
Coastal inundation
Coastal Erosion
Tsunami
SLR = Sea Level Rise
assumed to be 0.4m
over the next 50
years and 1m over
the next 100 years.
Almost all of Area 4 is subject to coastal inundation in a one in 50 year storm taking
into account sea level rise within the next 50 years. Much of the area may be
subject to coastal erosion, especially the bank edges.
The existing average ground elevation above perigean high tide level is 0.4m. Most
of the land in this area is within ±0.4m of these average levels.
For more information on coastal hazards, Christchurch City Council have a web
page dedicated to coastal hazards which can be accessed at:
http://www.ccc.govt.nz/environment/land/coast/coastalhazards/
Information on tsunami risk is available at:
http://ecan.govt.nz/advice/emergencies-and-hazard/tsunami/Pages/southamerican-tsunami-modelling.aspx
Flooding
ARI = Average
Recurrence Interval
All Area 4 falls within the proposed Christchurch Replacement District Plan Flood
Management Area (200 year flood event), and about three-quarters of the area
falls within the High Flood Hazard Management Area (more than 1m depth in 500
year flood).
Area 4 is away from the main floodway, so it may be possible to place fill without
exacerbating flooding elsewhere. If it was proposed to raise the land above flood
level, the average fill height needed would be about 1.2m. Any filling would need
to allow drainage to prevent damming of runoff from the green zone to the east.
The depth of flooding for 50 and 200 year flood events with 1m sea level rise may
be over 0.7m for most of Area 4, with the south-eastern end of Area 4 with over
1.0 of flood depth. In the 200 year scenario, the extent of this deeper water
increases.
It is noted that Cockayne Reserve provides a geographic buffer for Area 4 from the
Ōtākaro/Avon River.
For further information on flood hazards refer to the: ‘Flooding’ and ‘District Plan’
pages on the Regenerate Christchurch webpage.
Geotechnical
Earthquake induced
Liquefaction, lateral
spreading
Subsidence
(consolidation)
In Area 4, the main geotechnical constraint is the thin and weak non-liquefying
ground surface crust, resulting in the potential for moderate to severe
liquefaction-induced subsidence. There are also constraints due to the potential
for major area-wide lateral spreading towards the river.
For more information on geotechnical issues in this area refer to the following
geotechnical summary:
http://ceraarchive.dpmc.govt.nz/documents/flat-land-geotechnical-summaries
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Contamination
LLUR Listed Land Use
Register
Hazardous Activities and Industries List (HAIL) sites associated with storage tanks,
service station, workshop, waste disposal and coal/firewood yard. The age of
dwellings means that soil contamination from asbestos is possible.
Infrastructure
Wastewater
Wastewater mains cross this area, following the alignment of Bower Avenue
north/south, as well as New Brighton Road in an east/west direction, along
Rawson and at the eastern boundary of the sub-area along Hawke Street.
Water supply
A water supply main follows New Brighton Road for the length of the area, with an
extension northwards up Pratt Street. A pumping station is situated to the north in
Rawhiti Domain.
Stormwater
management
Stormwater mains cross the area, discharging into the Ōtākaro/Avon River at
Bower Avenue, and in five separate points between Palmers Road and Hawke
Street.
In June 2015, Christchurch City Council lodged a resource consent application with
Environment Canterbury for the discharge of water and contaminants to land and
water, including coastal water, from the existing and future reticulated
stormwater network. The proposal includes all reticulated networks within
Christchurch City and Banks Peninsula.
Parts of the residential red zone have been identified under the Ōtākaro/Avon
Stormwater Management Plan (appended to the resource consent application) as
being potentially developed as a detention storage basin, first flush basins and
wetland to service the adjacent existing urban area. The construction of such
facilities will depend on the outcome of decisions relating to the future use of the
residential red zone.
Submissions have closed on the application and a hearing is expected to proceed
after February 2017. Further details can be found at:
http://ecan.govt.nz/get-involved/consent-projects/cccstormwater/pages/notification.aspx
Transport
This area is accessed from New Brighton Road, which is classified as a Main
Distributor/Collector road, extending the length of the southern boundary of Area
4A.
Local streets Palmers, Baker, Rawson and Pratt connect long residential roads in
the green zone to New Brighton Road. These have been assessed by Council
transport engineers as important transport links between the green zone and the
wider traffic network.
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